I always keep my pda in the cradle charging whenever I can (most of an average day) just like the instructions say so. A guy I work with says it's better for battery life to discharge them (near) fully and then recharge.
My battery life is now very short (after about 10 months use) and I am going to buy a replacement. Anyone know for sure which is the best way to keep batteries in good shape?
Thanks in advance ... Dr Firstpost
http://www.batteryuniversity.com/parttwo-34.htm
How to prolong lithium-based batteries
Battery research is focusing heavily on lithium chemistries, so much so that one could presume that all portable devices will be powered with lithium-ion batteries in the future. In many ways, lithium-ion is superior to nickel and lead-based chemistries and the applications for lithium-ion batteries are growing as a result.
Lithium-ion has not yet fully matured and is being improved continuously. New metal and chemical combinations are being tried every six months to increase energy density and prolong service life. The improvements in longevity after each change will not be known for a few years.
A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.
Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate. (Read more in 'Choosing the right battery for portable computing', Part Two.)
Aging of lithium-ion is an issue that is often ignored. Depending on the state-of-charge and storage temperature, lithium-based batteries have a typical lifetime of 2-3 years (longer if partially charged and kept cool). The clock starts ticking as soon as the battery comes off the manufacturing line. The capacity loss manifests itself in increased internal resistance caused by oxidation. Eventually, the cell resistance will reach a point where the pack can no longer deliver the stored energy, although the battery may still contain ample charge. Increasing internal resistance is common to cobalt-based lithium-ion, a chemistry that is found in laptops and cell phones. The lower energy dense manganese-based lithium-ion, also known as spinel, maintains the internal resistance through its life but loses capacity due to chemical decompositions.
The speed by which lithium-ion ages is governed by temperature and state-of-charge. Figure 1 illustrates the capacity loss as a function of these two parameters.
Figure 1: Permanent capacity loss of lithium-ion as a function of temperature and charge level.
High charge levels and elevated temperatures hasten permanent capacity loss. Improvements in chemistry have increased the storage performance of lithium-ion batteries.
There are no remedies to restore lithium-ion once worn out. A momentary improvement in performance is noticeable when heating up the battery. This lowers the internal resistance but the condition reverts back to its former state when the temperature drops.
If possible, store the battery in a cool place at about a 40% state-of-charge. Some reserve charge is needed to keep the battery and its protection circuit operational during prolonged storage. The most harmful combination is full charge at high temperature. This is the case when placing a cell phone or spare battery in a hot car. Running a laptop computer on the mains has a similar temperature problem. While the battery is kept fully charged, the inside temperature during operation rises to 45°C (113°F).
Removing the battery from the laptop when running on fixed power protects the battery from heat but some battery and laptop manufacturers caution against it. They say that dust and moisture accumulating inside the battery casing could damage the laptop. The dealers will be happy to provide you with a new pack when a replacement is needed a little sooner.
The question is often asked, should the laptop be disconnected from the main when not in use? With lithium-ion it does not matter. Once the battery is fully charged, no further charge is applied. It is recommended, however, to turn the laptop off overnight because heat harms the battery.
A large number of lithium-ion batteries for cell phones are being discarded under the warranty return policy. Some failed batteries are sent to service centers or the manufacturer, where they are refurbished. Studies show that 80%-90% of the returned batteries can be repaired and returned to service.
Some lithium-ion batteries fail due to excessive low discharge. If discharged below 2.5 volts per cell, the internal safety circuit opens and the battery appears dead. A charge with the original charger is no longer possible. Some battery analyzers (Cadex) feature a boost function that reactivates the protection circuit of a failed battery and enables a recharge. However, if the cell voltage has fallen below 1.5V/cell and has remained in that state for a few days, a recharge should be avoided because of safety concerns. To prevent failure, never store the battery fully discharged. Apply some charge before storage, and then charge fully before use.
All personal computers (and some other electronic devices) contain a battery for memory back up. This battery is commonly a small non-rechargeable lithium cell, which provides a small current when the device is turned off. The PC uses the battery to retain certain information when the power is off. These are the BIOS settings, current date and time, as well as resource assignment for Plug and Play systems. Storage does shorten the service life of the backup battery to a few years. Some say 1-2 years. By keeping the computer connected to the main, albeit turned off, a battery on the PC motherboards should be good for 5-7 years. A PC should give the advanced warning when battery gets low. A dead back-up battery will wipe out the volatile memory and erase certain settings. After battery is replaced, the PC should again be operational.
Simple Guidelines
Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.
Batteries with fuel gauge (laptops) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.
Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the battery at a 40% charge level.
Consider removing the battery from a laptop when running on fixed power. (Some laptop manufacturers are concerned about dust and moisture accumulating inside the battery casing.)
Avoid purchasing spare lithium-ion batteries for later use. Observe manufacturing date. Do not buy old stock, even if sold at clearance prices.
If you have a spare lithium-ion battery, use one to the fullest and keep the other cool by placing it in the refrigerator. Do not freeze the battery. For best results, store the battery at 40% state-of-charge.
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Created: February 2003, Last edited: June 2005
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About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc
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V
The short answer.
No. Lithium batteries prefer to be topped up frequently and don't like being fully discharged.
Thanks TheBrit :wink:
Just to add - you can do damage to a lithium battery by entirely discharging it, so don't. Top up away. But expect to replace after a couple of years!
V
Thanks for the replys & detail.
Maybe my batteries are suffering from 'digital memory' - they have hardly ever been run down to device switch-off. For my new ones I'll try fully discharging every 30 recharges as suggested and see how that goes.
I'll post results of test in a years time!
I don't believe in topping them constantly. A friend and I bought our new phones 2 weeks apart from each other. I always heard to discharge them before charging, he on the other hand never cared. Just 6 months in now, his dies in 2 hours or less, with light use. I am playing music, surfing FB etc. all day long. Right now at 15 hours discharging and still 40% battery. He has charged his 5 times today due to phone going into low battery life, and only been up 11 hours.
It only happens with the Niquel-Cadmium not with the Lithium
jrodcamaro said:
I don't believe in topping them constantly. A friend and I bought our new phones 2 weeks apart from each other. I always heard to discharge them before charging, he on the other hand never cared. Just 6 months in now, his dies in 2 hours or less, with light use. I am playing music, surfing FB etc. all day long. Right now at 15 hours discharging and still 40% battery. He has charged his 5 times today due to phone going into low battery life, and only been up 11 hours.
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Wut
I’ve, in all Windows Mobile forums, very often posted on the fact that Lithium-Ion / Polymer batteries should always be recharged whenever possible. That is, you should put your handheld / handset on the charger whenever possible. NEVER EVER wait before the handheld shuts down because even after only 4 months, your battery will only hold about a third (!) of its original charge holding capacity and, as opposed to what several people say, putting the device on the charger only once a day (or two-three days with devices with better battery life – mostly, TI OMAP-based handsets) on a regular basis (not waiting for the battery to completely deplete) will also have an adverse effect on the battery life.
Now, Groucho's pretty cool Nokia N95 blog has published a remarkable article, which is of extreme interest to anyone having a device with a Lithium Ion or Polymer-based rechargeable battery (not only Nokia N95 users – again, this info applies to ALL current Windows Mobile handsets, and a lot more other gadgets like digital cameras etc.). The figures he shows certainly prove I’ve been right when I recommended recharging your device whenever possible.
Groucho has purchased three N95’s (again and again, don’t think this discussion only applies to the N95 – it does apply to ANY device out there!) at the same time and used them in a pretty similar way. He, however, made absolutely sure he charged the device in three consistent (not mixing up the devices) and radically different ways: the first was charged only once a day (every night), not during the day; the second was charged when it has completely shut down because of the battery’s going flat and the third was almost always on charger whenever possible. The difference in the battery capacity, based on the different ways of recharging, turned out to be astonishing: the second battery (which was always let go flat, and only after that was it put on a charger) could only hold slightly more than a third of the battery that was always on charger whenever possible. The latter battery, in addition, fared considerably (about 16%) better than the battery only regularly (every night) recharged.
Note that the blog post has a mistake (which has no effect on the credibility of the results): it states they will have exactly the same charge holding capabilities throughout their life, and, suddenly, they die (“They have a finite shelf life which starts from the day they are manufactured and their condition from then degrades to the point where they fail! This is not to be confused with their charge holding abilities which are very good for their full life! When they go they just go!”). This is, of course, incorrect: their capacity will degrade over time. Just an example: my HP iPAQ 2210, which I bought right after it was released in Europe, at first, shut down at 2-3% battery level. After about two years, this raised to about 20% and, after three years, this was already around 35-38%. This also shows – along with a multitude of other examples – that these batteries do lose capacity over time. Also note that, as I’ve also recommended several times, Battery University has a decent article on all these questions – except for, of course, real-world results like the above.
Verdict: ignore if somebody says the opposite. Recharge your handheld whenever possible.
Menneisyys said:
I’ve, in all Windows Mobile forums, very often posted on the fact that Lithium-Ion / Polymer batteries should always be recharged whenever possible. That is, you should put your handheld / handset on the charger whenever possible. NEVER EVER wait before the handheld shuts down because even after only 4 months, your battery will only hold about a third (!) of its original charge holding capacity and, as opposed to what several people say, putting the device on the charger only once a day (or two-three days with devices with better battery life – mostly, TI OMAP-based handsets) on a regular basis (not waiting for the battery to completely deplete) will also have an adverse effect on the battery life.
Now, Groucho's pretty cool Nokia N95 blog has published a remarkable article, which is of extreme interest to anyone having a device with a Lithium Ion or Polymer-based rechargeable battery (not only Nokia N95 users – again, this info applies to ALL current Windows Mobile handsets, and a lot more other gadgets like digital cameras etc.). The figures he shows certainly prove I’ve been right when I recommended recharging your device whenever possible.
Groucho has purchased three N95’s (again and again, don’t think this discussion only applies to the N95 – it does apply to ANY device out there!) at the same time and used them in a pretty similar way. He, however, made absolutely sure he charged the device in three consistent (not mixing up the devices) and radically different ways: the first was charged only once a day (every night), not during the day; the second was charged when it has completely shut down because of the battery’s going flat and the third was almost always on charger whenever possible. The difference in the battery capacity, based on the different ways of recharging, turned out to be astonishing: the second battery (which was always let go flat, and only after that was it put on a charger) could only hold slightly more than a third of the battery that was always on charger whenever possible. The latter battery, in addition, fared considerably (about 16%) better than the battery only regularly (every night) recharged.
Note that the blog post has a mistake (which has no effect on the credibility of the results): it states they will have exactly the same charge holding capabilities throughout their life, and, suddenly, they die (“They have a finite shelf life which starts from the day they are manufactured and their condition from then degrades to the point where they fail! This is not to be confused with their charge holding abilities which are very good for their full life! When they go they just go!”). This is, of course, incorrect: their capacity will degrade over time. Just an example: my HP iPAQ 2210, which I bought right after it was released in Europe, at first, shut down at 2-3% battery level. After about two years, this raised to about 20% and, after three years, this was already around 35-38%. This also shows – along with a multitude of other examples – that these batteries do lose capacity over time. Also note that, as I’ve also recommended several times, Battery University has a decent article on all these questions – except for, of course, real-world results like the above.
Verdict: ignore if somebody says the opposite. Recharge your handheld whenever possible.
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An excellent post and very valuable info.It'll certainly help out many,who believe that the batteries shud only be charged once a day or when it's almost finished or going flat,by this the life of the batteries is saved and prolonged as against to charging whenever possible or more than once in a day,this concept is believed as charging more than one time will create a new charging point every time and will not fully charge the battery,thus,will impact the charge retaining capabilities of the battery and ultimately die out soon.
You are absolutely correct in saying that "This is, of course, incorrect: their capacity will degrade over time."and "that these batteries do lose capacity over time",Of course,they have a finite life cycle from the day they are manufactured,infact every gadget,machinery,electric appliances,PCs,Tvs and all everyday utilities have a life cycle and will die out with passage of time and longer use.
It has been observed in this and many other forums,people posting that their devices have gone dead due to battery going flat as they forgot to charge it. Than it becomes a pain in the A** to get it recharged again and get the phone alive again, Therefore,to avoid this dreadful scenario,it is always better to get the battery charged whenever possible,CUZ IT'S GONNA DIE OUT SOMEDAY,for sure,whether you charge it once a day or when it's gone flat or charge it whenever possible,but definitely save yourself from the horrible situation of getting a dead phone,due to a flat battery and frustrating ways to get it charged again.
Just to mention here,it's my personal experience, as I myself got into this situation once,while in a hurry and urgency,I forgot to get the battery charged and didn't realize it was almost going flat,after a couple of hours,suddenly the phone went dead,I wanted to make some very important calls,but there was no way I cud get the phone Power On,frantically started to look for ways to get it charged as I didn't have the charger with me,I tried to get it charged through usb connection with the Pc,but NO GO,it never started charging and there were no lights on the phone,In short I tried in many ways to get it charged and phone started.
Even,when I got back home,tried it with the Wall charger,it refused to charge,I got horrified.took it to a service shop.They said that while my trying to get it charge through various methods and again n again trying to wake the phone,the Pulse of the battery has gone down from the level,which it requires to communicate with the phone and start charging,Ultimately,it has to be Jump Started to get it working,therefore,I made a rule of my everyday working to get it charged a couple of times during the day,Now I have never to fear and face that dreadful situation again,And let me point out here that I have not seen any degration in the charging or performance of the battery so far as I'm doing this since last six months or so.
Thank you for confirming my believes in charging for more than once is advisable and will not effect much on the battery charge retention and life cycle
Cheer
Good writing ! I didn't know that it affected the battery that much! Thanks!
You are correct in saying that only charging a device when it has run down to 0% (or close) is bad for Lithium Ion batteries. That incorrect advice is left over from the Nickel Cadmium (Ni-Cd) era, when it worked on batteries with that chemistry to prolong their life due to the "memory effect".
But I don't think saying that Li-Ion batteries should be charged "as often as possible" is quite right, because keeping them at or near 100% charge WILL shorten their life, just like keeping them at or near 0% will (but not as much admittedly).
If you want to maximize the life of your Li-Ion batteries, you should make sure that they don't get any hotter than 25 degrees celcius (77F), and you should try to keep them in a state of 40% to 60% charge as much as possible (that means take it out of the charger without letting it get to 100%!).
Of course keeping it between 40% and 60% only lets you use 20% of the battery's full capacity, which is not convenient at all! So the next best thing is to charge it to 100%, then recharge it when it gets down to 40%.
Letting it get below 40% is the most damaging, but constantly keeping it above 60% charge is also damaging in the long term.
One last tip: Li-Ion batteries last longer the slower you charge them. So charge them with USB from the computer rather than an AC mains adapter, as this is usually the slower method (USB from a computer contains 0.5 Amps of current, whereas many AC chargers supply 1.0 to 1.5 Amps, even though they may have a "USB" connector).
Everything above can be backed up by various sources, here is a very good one: http://www.batteryuniversity.com/parttwo-34.htm
Interesting you mention charging at different amperes. There are quite a few quick-charge standard battery charges around the place that always state they will boost the battery up to 80% quite fast then the remainder takes a further few hours. This also usually causes the batteries to become excessively hot.
The 110/230 Volt mains charger that came with my Trinity charges really fast but definitely heats it to over 25°C. However the mains to miniUSB charger that came with my cradle, and the one that came with my BT headset both charge at a much slower (and cooler) rate, likely to be 0.5 Amps. I checked out the labels and they all indicate the same ratings. I know, I should chuck the multimeter on them to test…
Maybe I’ll go back to using the cradle mains charger when I’m at home and my PC isn’t on (as if that ever happens)
sl9 said:
But I don't think saying that Li-Ion batteries should be charged "as often as possible" is quite right, because keeping them at or near 100% charge WILL shorten their life, just like keeping them at or near 0% will (but not as much admittedly).
If you want to maximize the life of your Li-Ion batteries, you should make sure that they don't get any hotter than 25 degrees celcius (77F), and you should try to keep them in a state of 40% to 60% charge as much as possible (that means take it out of the charger without letting it get to 100%!).
Of course keeping it between 40% and 60% only lets you use 20% of the battery's full capacity, which is not convenient at all! So the next best thing is to charge it to 100%, then recharge it when it gets down to 40%.
Letting it get below 40% is the most damaging, but constantly keeping it above 60% charge is also damaging in the long term.
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Yup, 60% is the best usage scenario. However,
1. it does have a severe problem: the reduced battery life (60% vs. 100%), which may render its usage problematic in some cases (when you do need the remaining 40%). That is, it's only really usable when you are absolutely sure you can recharge your device when it's still, say, abouve 30%, leaving you an about 30% usability area.
2. the advantage of keeping teh battery around 60% (as opposed to 100%), battery capacity saving-wise, isn't so prevalent than recharging the battery whenever possible. That is, while keeping the battery at around 60% does result in better charge holding after X time, it's net effect is still much lower than, say, letting the battery go flat. As can be seen in the linked report, you can almost completely kill (leaving about 40% of the original charge holding capability) a Li-Ion battery in no more than four months. The 60% rule (as opposed to the 100% one) has far less (albeit, of course, considerable) advantages - on the long run.
BTW, I do the following: I keep my spare batteries I requently (say, in general, once a week or two weeks) use at around 70-80% (it's, being halfway between 60% and 100%, a tradeoff) and batteries I don't use at all (for example, my old Casio Cassiopeia batteries) at 40%.
There is some really interesting discussion of this article at MoDaCo, HowardForums, FirstLoox, PPCT, XDA-Developers - well worth checking out for more info / discussion.
sl9 said:
One last tip: Li-Ion batteries last longer the slower you charge them. So charge them with USB from the computer rather than an AC mains adapter, as this is usually the slower method (USB from a computer contains 0.5 Amps of current, whereas many AC chargers supply 1.0 to 1.5 Amps, even though they may have a "USB" connector).
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A quick note: if you know your power source is only capable of providing, say, 0.5A's, you might want to make absolutely sure its voltage doesn't drop under, say, 4.5 Volts at 0.5A. A lot of power sources (this is perfectly natural with all kinds of power transformators) do this; then, the batteries / the phone's electronics starts to struggle with providing the necessay charging voltage (IIRC, 4.2 Volts).
Also, the permanent damage of (or caused by) these chargers can also be a problem - I don't think a cheapo notebook has decent voltage stabilizators. An expensive IBM / Lenovo Thinkpad will never cause any problem to a USB device (they have VERY good USB protection - I've myself found this out with my a31p once, when I, accidentally, made a short circuit on the USB). A cheapo notebook is likely to use the cheapest (read: parts that not necessarily can stand even 0.5 Ampers) parts.
I have a laptop and a phone, both using original batteries and both around 4 years old now. The laptop is a dell with a 7 aH Li-Ion battery and the phone is a Nokia 6310i with a factory Li-Polymer battery. As I said, original standard batteries that came in the original package. Both have only been used with company standard chargers - no quick force-feed cradles here.
If I start with the phone, it is one of the best I ever had. I don't make many calls on this phone, mainly text messages, and it spends the most of it's time just idling. At night I usually turn it off, sometimes I use the temporary profile option with tone/vibration off, as I sleep better knowing the phone will not wake me up. I had a collegue who bought the same type of phone as me, and we treated it way different. First of all, he used it a lot more. Second of all, the charger went in and out quite often, and he often used the phone while it was charging. I have consistently only charged this phone to 100%, usually overnight. Sometimes charging it when it was quite low, but most of the time after about a week. This phone last two weeks on standby (if used during daytime only), and after 4 years ... it still does! It was the first triband Nokia made (to my knowledge), and I got one of the first ones in stead of getting the third Ericsson T39m in the same year (kept failing!). My collegues phone did not even last a day on a full charge, in LESS THAN HALF A YEAR. Now, four years after, my phone still last me two weeks with the minor use I demand of it.
Most notable habits for handling the phone/battery:
Very seldom used during recharging
Almost always charged uninterrupted to 100% - in off position or without using it
Not so heavy use
My collegue on the other hand interrupted the charge before reaching 100%, used it while on the charger and his battery died down to almost no capacity sooooo fast.
As for my Laptop, it is a Dell Inspiron 8600, and after 4 years, it still runs almost two hours on the original battery, using internet, wireless and bluetooth simultaneously and not going into any kind of power save.
Below is the way I have generally used it:
I have seldom removed the battery while on mains, as I find it difficult and also enjoy the safety of the battery being there if I pull the chord, power outtage etc. Contrary to my phone, I use my laptop A LOT, like, daily, for many hours usually, sometimes all day. It is mainly work related, reading/writing documents, some graphic work and so on. Not so much watching movies, but sometimes certain programs like OCR or other runs keep the CPU to 100% for a while. I mainly keep the battery in and charged, and unless the ambient temperature is high or I sit with the laptop on top of my lap where my body heat heats the battery, I have not found the battery to heat up much. Even when the fan is going 100% on a heavy load, the battery temp seems OK. For various practical reasons, I have more often recently used my laptop on battery until just before it cuts out by itself. I must say I did not check if that makes the battery hot, but after 4 years, I still get almost two hours of use with wireless and bluetooth enabled. I have friends and collegues who replace the battery after one or two years, because it is down to almost nothing in capacity.
Any battery powered device I have had in the last 5 years or so I have been treating with these golden rules, and none of them have had to have batteries changed so far ...
Do not interrupt battery until it is done charging (unless on trickle charge, obviously)
Charge any time you like, as long as you obey the rule above
Do not place a heavy load on the device while it is charging after having been run on batteries (again, trickle charge is OK while on mains)
A good way to accomplish these rules is to have a habit of charging devices before you sleep, even before being worn down (charging not so likely to be interupted by sudden change of plans).
Having run my laptop for thousands of hours with battery inside and connected to mains, for me after 4 years it has not killed my battery.
This is not scientific research, but for me, it has worked for all my devices - for whatever reason. Those who complain their batteries die quickly seem to be the ones who pulls the charger whenever they want.
Although lithium batteries are somewhat different than the way humans store and use their energy, it seems to me there are some similarities:
Does not like it too hot or too cold
If not allowed to eat/charge fully on a regular basis, charging more often is necessary.
Can get annoyed if suddenly disrupted during feeding/charging.
If force fed, less energy can be taken up compared to a slow and easy feed.
This is not meant as proof, as in "because humans are like this, so are batteries", but to me, it just seems coincidental that there are some similarities. Me, personally, I eat one to three times a day. Yes, I can do with one meal a day, but two meals a day I think are optimum for me. Consistently eating 3 or more times a day makes my weight go up, I have been over 200 pounds for my 6'3" after being in a job for a year where I "was fed" too often. Now, I am fit and healthy at around 170 lbs, I seldom have headaches or fatigue, and I have an endurance like not many others! Without "charging" I can last a long time. Give me a good evening meal, and the next morning I can run a half marathon with no breakfast, just water.
Conclusion: Let the facts of real life be your proof instead of going after experts opinion. Let's have more experiments to find the real truth!
1, you're pretty fortunate your notebook battery is still going strong. I've never seen a notebook battery SO good - the situation you've described doesn't even seem to adhere to the laws of chemistry (that is, after two years, a Li-Ion battery kept consistently at 100% charging level is bound to lose at least 20% of its original capacity, independent of the usage).
2, the human vs. battery comparison, IMHO, isn't the best. Most feeding / intake specalists state one should prefer the way of "eat many times a day, but little each time" - that is, say, some 4-5 apples, tomatoes, cucumbers etc. a day, say, one (or two) every hour - at least this is what I do at work. I also refrain from eating a lot at lunchtime - I, generally, eat a quarter portion, and take the rest with me, continuously eating it later say, a bit every hours. This surely won't result in getting fat - on the contrary. If, of course, you don't keep your stomach at 100% load level
nice tip on eating...
I wrote specifically that it was not proof or anything, it just seems that some things are similar. My laptop batter has probably lost a little, but the way I have treated it, it still works after 4 years, where collegues/friends a long time ago would have had to get new batteries. I did not make specific measurements, but maybe a new battery would last me around 2.5 hours instead of two, but I have seen batteries that last 5 minutes, and they are less than 2 years old.
So what is a "good way" to kill a battery fast? I thought that stopping charging before 100% is one of the ways to kill a battery, but as soon as I see a test where it is proved that it is the other way around, I'd be happy not to have to wait for 100% before pulling the plug. But the mentioned Nokia test is only varying on when to start the recharging, not when to end it.
As for the comparison to humans ... I know they say you should eat many small meals a day, and that is great if you measure your meals precisely in calories and content. But for a normal, daily unscientific diet, many of those people I hear reiterate the "eat many but small meals to loose weight" have them selves ... weight problems. I have proven that it works (for me), I can see my weight increase when I get into periods of eating 3 or more meals a day. Same with my batteries. I can see they last a long time, where other peoples batteries die - so ... why does it work then?
I know this is kind of an old post (hah) but just an update about Li-Ion batteries:
The final 5-10% of charging is the part that does the most "wear and tear" of the whole charge process, this is the reason IBM (now Lenovo) Thinkpads don't charge the final bit all the time. So avoid *topping off* when charging. If done within the normal charging it shouldn't be a problem.
Simple Guidelines (taken from: http://www.batteryuniversity.com/parttwo-34.htm)
* Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.
* Batteries with fuel gauge (laptops) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.
* Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the battery at a 40% charge level.
* Consider removing the battery from a laptop when running on fixed power. (Some laptop manufacturers are concerned about dust and moisture accumulating inside the battery casing.)
* Avoid purchasing spare lithium-ion batteries for later use. Observe manufacturing dates. Do not buy old stock, even if sold at clearance prices.
* If you have a spare lithium-ion battery, use one to the fullest and keep the other cool by placing it in the refrigerator. Do not freeze the battery. For best results, store the battery at 40% state-of-charge.
does that mean if you have two batteries, you should only use one most of the time and keep the other one in storage?
I would have thought it would be better to alternate between the two every week or something. Nothing worse than having the battery in storage for a few months and then when you actually need it on a trip you find that it only has 50% capacity
Actually the article says that you should "store" batteries at 40% if you're keeping one as a backup, I think the best option would be to alternate them. Keeping one stored at 100% actually causes it to lose its charge FASTER than one stored at 40%
FYI : as you are charging/discharging your battery, the hysteresis threshold (this is called like this in electronic) is decreasing, when it's new it still at 100% then 99%,98%,97% etc
This is the reason why sometimes when you think your battery is fully loaded, his load stops at the hysteresis threshold.
In some case it's possible to raise this hysteresis threshold (when the battery is recent). and to retrieve the full charge.
Here is a tips that I use since some years (my ipaq 3660)
When your device show your battery 100% loaded (of course it's not) the LED light should go off. if you unplug your power AC, and plug it back, and if you notice that your device is loading a few seconds (3-5 sec) then you are raising the hysteresis threshold. of course not to 100%, but a little.
now, put a dvd movie, sit down, and repeat the tips as much as the light doesn't show the device is charging a few seconds. I mean is your battery is full loaded then when you plug back the power ac it should not charge again. so your hysteresis threshold is probably at 100% and your battery should work has a new one.
sorry if my english isn't good enough for this contrib.
Hello!
Does the phone or battery itself has over charge protection?
Is it safe leave the phone connected to a computer/charger all the time?
I've been using HTC Hermes for 2 years and already replaced 3 batteries, not sure if it was due to phone was connected to a charger for at least 12 hours a day or something else..
Thank you.
technically it should'nt be an issue. the phone can detect when its battery is full and can set itself to trickle charge (atleast that's what i've been told). You do want to atleast have it drain itself full once a month or have it off the power line ever so often to keep the energy moving otherwise it goes stagnant. (not exactly stagnant, but you know what i mean.. right?)
Draining battery is not a problem, the phone does a good job doing just that
With all the technology one could assume that an advanced phone like this would have a overcharge protection. But wanted make sure that it does.
[email protected] said:
With all the technology one could assume that an advanced phone like this would have a overcharge protection. But wanted make sure that it does.
Click to expand...
Click to collapse
No convinced it does myself. All the add-on chargers, cradles, etc. highlight having overcharge protection if they're any good. So perhaps it (overcharge protection) is a functionality of the charger and not the phone itself?
I know that when my phone is charging (battery not 100%) it's cool to touch, but when on charge (USB cable from PC, sync active) when the battery is full it's mildly warm to touch. Perhaps suggesting that incoming un-needed power is being converted into heat for dissipation?
To me, I think the phone probably has overcharge protection (whether it be the charging source, or teh phone itself by heat dissipation), but if your constantly leaving it on charge then perhaps the constant warmth is what's reducing your battery life?
Most charging control electronics is inside the phone, with some parts
inside the battery, like overheating protection and battery cell diagnostics.
Charging control checks the voltage rise during charging (actually difference
beetwen voltage before charging pulse and after that, so called delta voltage),
and when it reaches certain threshold, a charging unit switches to trickle
charging, which means "charging" with 1/10 or less of normal charging current,
amount which cannot cause perceivable warming. Most of warming happens
on final stage of normal charging, when battery is almost full, and its charge
accumulation efficiency drops, but is still being charged with the same current,
part of which, that cannot be accumulated, is dissipated as heat.
Heat dissipation
That heat dissipation is what has always concerned me. So I have bought extra batteries and external charges. I use the TP for business and some days out of the office a lot. Not unusual to go to two, occasionally three batteries in a day. That issue is my only "complaint" about this phone.
Updated and simplified version here : http://forum.xda-developers.com/showthread.php?p=3846897#post3846897
I've been around this forum for some time now and I have noticed one thing that is spelled in all sub-forums: BATTERY LIFE
So I thought of pulling some info together that is relevant to our Raphs (Li-ion batteries), taken from www.batteryuniversity.com.
Hope you find it helpful and understand better behaviour of your battery
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About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc., in Vancouver BC.
Mr. Buchmann has a background in radio communications and has studied the behavior of rechargeable batteries in practical, everyday applications for two decades. Award winning author of many articles and books on batteries, Mr. Buchmann has delivered technical papers around the world.
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"If possible, do not discharge lithium-based batteries too deeply. Instead, recharge more often."
Lithium-ion is a low maintenance battery, an advantage that most other chemistries cannot claim. There is no memory and no scheduled cycling is required to prolong the battery's life. In addition, the self-discharge is less than half compared to nickel-cadmium, making lithium-ion well suited for modern fuel gauge applications.
Lithium-ion has not yet fully matured and is being improved continuously. New metal and chemical combinations are being tried every six months to increase energy density and prolong service life. The improvements in longevity after each change will not be known for a few years.
Charging
There is only one way to charge lithium-based batteries. The so-called 'miracle chargers', which claim to restore and prolong batteries, do not exist for lithium chemistries. Neither does super-fast charging apply. Manufacturers of lithium-ion cells have very strict guidelines in charge procedures and the pack should be charged as per the manufacturers "typical" charge technique.
Lithium-ion is a very clean system and does not need priming as nickel-based batteries do. The 1st charge is no different to the 5th or the 50th charge. Stickers instructing to charge the battery for 8 hours or more for the first time may be a leftover from the nickel battery days.
Most cells are charged to 4.20 volts with a tolerance of +/?0.05V/cell. Charging only to 4.10V reduced the capacity by 10% but provides a longer service life. Newer cell are capable of delivering a good cycle count with a charge to 4.20 volts per cell.
A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.
Batteries live longer if treated in a gentle manner. High charge voltages, excessive charge rate and extreme load conditions have a negative effect on battery life. The longevity is often a direct result of the environmental stresses applied. The following guidelines suggest ways to prolong battery life.
The time at which the battery stays at 4.20/cell should be as short as possible. Prolonged high voltage promotes corrosion, especially at elevated temperatures. Spinel is less sensitive to high voltage.
The lower charge current reduces the time in which the cell resides at 4.20V. A 0.5C charge only adds marginally to the charge time over 1C because the topping charge will be shorter. A high current charge tends to push the voltage into voltage limit prematurely.
Do not discharge lithium-ion too deeply. Instead, charge it frequently. Lithium-ion does not have memory problems like nickel-cadmium batteries. No deep discharges are needed for conditioning.
Do not charge lithium-ion at or below freezing temperature. Although accepting charge, an irreversible plating of metallic lithium will occur that compromises the safety of the pack.
Not only does a lithium-ion battery live longer with a slower charge rate; moderate discharge rates also helps.
Discharge of the lithium-ion battery is 5% in the first 24 hours after charge, and then reduces to 1% to 2% per month thereafter. The safety circuit adds about 3%. High cycle count and aging have little effect on the self-discharge of lithium-based batteries.
The battery industry is making incremental capacity gains of 8-10% per year. This trend is expected to continue. This, however, is a far cry from Moore's Law that specifies a doubling of transistors on a chip every 18 to 24 months. Translating this increase to a battery would mean a doubling of capacity every two years. Instead of two years, lithium-ion has doubled its energy capacity in 10 years.
Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate.
Despite its overall advantages, lithium-ion has its drawbacks. It is fragile and requires a protection circuit to maintain safe operation. Built into each pack, the protection circuit limits the peak voltage of each cell during charge and prevents the cell voltage from dropping too low on discharge. In addition, the cell temperature is monitored to prevent temperature extremes. The maximum charge and discharge current on most packs are is limited to between 1C and 2C. With these precautions in place, the possibility of metallic lithium plating occurring due to overcharge is virtually eliminated.
The worst condition is keeping a fully charged battery at elevated temperatures, which is the case with running laptop batteries. If used on main power, the battery inside a laptop will only last for 12-18 months. I must hasten to explain that the pack does not die suddenly but begins with reduced run-times.
The voltage level to which the cells are charged also plays an important role to longevity. For safety reasons, most lithium-ion cannot exceed 4.20 volts per cell. While a higher voltage boosts capacity, the disadvantage is lower cycle life.
"how deep can a battery be discharged and still achieve maximum service life?" There are no definite answers. Batteries are like us humans. Suppose we ate all the vegetables our mother heaped on our plates and do our daily exercise, would we life longer? Perhaps. But by how much, no one will know. Batteries lose capacity as part of aging, cycling and exposure to heat. Nickel-cadmium also loses capacity due to lack of exercise because of memory.
Some lithium-ion batteries fail due to excessive low discharge. If discharged below 2.5 volts per cell, the internal safety circuit opens and the battery appears dead.
Aging is a concern with most lithium-ion batteries and many manufacturers remain silent about this issue. Some capacity deterioration is noticeable after one year, whether the battery is in use or not.
Lithium-ion batteries lose capacity through cell oxidation, a process that occurs naturally during use and aging. The typical life span of lithium-ion is 2-3 years under normal use. Cool storage a 40% charge minimizes aging. An aged lithium-ion cannot be restored with cycling.
Shorted Cells
Cell reversal caused by deep discharging also contributes to shorted cells.Specified to deliver 100% capacity when new, the battery should be replaced when the capacity drops to below 80% of the nominal rating.
The self-discharge on all battery chemistries increase at higher temperatures. Typically, the rate doubles with every 10°C (18°F). A noticeable energy loss occurs if a battery is left in a hot vehicle.
Premature voltage cut-off
Not all stored battery power can be fully utilized. Some equipment cuts off before the designated end-of-discharge voltage is reached and precious battery energy remains unused. Applications demanding high current bursts push the battery voltage to an early cut-off. This is especially visible on batteries with elevated internal resistance. The voltage recovers when the load is removed and the battery appears normal. Discharging such a battery on a moderate load with a battery analyzer to the respective end-of-discharge threshold will sometimes produce residual capacity readings of 30% and higher.
Counterfeit cell phone batteries (clone batteries)
In the search for low-cost battery replacements, consumers may inadvertently purchase clone cell phone batteries that do not include an approved protection circuit. Lithium-ion packs require a protection circuit to shut off the power source if the charger malfunctions and keep on charging, or if the pack is put under undue stress (electrical short). Overheating and 'venting with flame' can be the result of such strain.
Cell phone manufacturers strongly advise customers to replace the battery with an approved brand. Failing to do so may void the warranty. Counterfeit cell phone batteries have become visible since the beginning of 2003 when the world was being flooded with cheap replacement batteries from Asia.
Cell phone manufacturers act out of genuine concern for safety rather than using scare tactics to persuade customers to buy their own accessories. They do not object to third party suppliers in offering batteries and chargers as long as the products are well built, safe and functioning. The buyer can often not distinguish between an original and a counterfeit battery because the label may appear bona fide.
Caution should also be exercised in purchasing counterfeit chargers. Some units do not terminate the battery correctly and rely on the battery's internal protection circuit to cut off the power when fully charged. Precise full-charge termination and a working protection circuit are needed for the safe use of the lithium-ion battery.
A large number of lithium-ion batteries for cell phones are being discarded under the warranty return policy. Some failed batteries are sent to service centers or the manufacturer, where they are refurbished. Studies show that 80%-90% of the returned batteries can be repaired and returned to service.
© Copyright 2003 - 2005 Isidor Buchmann
Great thread! Wiki!
Thanks
Tis is good info to know and to share. Thanks for putting this together for us all.
overcharging Fuze battery
When I exchanged my Fuze for a new one at AT&T, the service person said my battery was bad, due to overcharging. She said leaving my Fuze plugged into my car charger and my computer(with charging turned on) degraded the battery.
There is an option to NOT charge the battery when connected by USB to the computer.(kind of indicates no automatic charging control)
Well, I use my Fuze as a computer 12-14 hours a day. I want to see the screen, which means I need it plugged in either to the computer or car charger.
If I turn off recharging when connected to my computer, I end up with a dead battery pretty quickly, since I use it a lot as my business phone with a Bluetooth speakerphone.
The AT&T person said this information was given to them by HTC.
Thank you for the infos. Really need this cause battery life is my main concern.
recharge cycles
from reading other posts, it looks like the batteries have around 1000 recharge cycles.
Unfortunately, the cycles can occur every time you plug into your computer or charger, even if the charge goes from 99 to 100 %.
Which means I need a new battery probably every 9-12 months. Not too bad.
hrothnir said:
When I exchanged my Fuze for a new one at AT&T, the service person said my battery was bad, due to overcharging. She said leaving my Fuze plugged into my car charger and my computer(with charging turned on) degraded the battery.
There is an option to NOT charge the battery when connected by USB to the computer.(kind of indicates no automatic charging control)
Well, I use my Fuze as a computer 12-14 hours a day. I want to see the screen, which means I need it plugged in either to the computer or car charger.
If I turn off recharging when connected to my computer, I end up with a dead battery pretty quickly, since I use it a lot as my business phone with a Bluetooth speakerphone.
The AT&T person said this information was given to them by HTC.
Click to expand...
Click to collapse
Which tells you how much you should listen to most AT&T people about technical issues and details. They were 100% wrong about the impact of charging continuously. And unless they were talking to an HTC hardware engineer...
It's more likely that your issues were simply caused by heavy use, which will cause any rechargeable battery to wear out more quickly. Most batteries I've seen will last between 500-1000 charging cycles, so if you're a heavy user and are wearing down your battery frequently, you'll "run through" those charging cycles more quickly.
The advice you were given is worth ignoring.
does it make any difference
Does it make any difference if i charge my fuze from a
- charger connected to power outlet
or
- an USB cable connected to compute
Obviously, the USB option takes longer time to charge completely.
I wanted to know, which is suggested?
hrothnir said:
from reading other posts, it looks like the batteries have around 1000 recharge cycles.
Unfortunately, the cycles can occur every time you plug into your computer or charger, even if the charge goes from 99 to 100 %.
Which means I need a new battery probably every 9-12 months. Not too bad.
Click to expand...
Click to collapse
Charging from 99-100% definitely will not qualify as "One" cycle. Discharging from 100% to some 20% and then charging up may count as one cycle. Similarly, 5 or 6 shallow discharging and charging 60%-40%-60% can count as one cycle. It is much better for battery health though. charging momentarily for one or two minutes which increases the battery percentage by 2-3% will not count as a full cycle.
To power up, you consume Red Bull. But your phone just needs its adaptive fast charger. Rate this thread to express how quickly the OnePlus 6T can charge. A higher rating indicates that it charges extremely fast.
Then, drop a comment if you have anything to add!
dash charge (now called fast charge) is crazy fast!!
Still, I would only recommend using that feature if there is a real benefit - i.e. time is of the essence. The battery will age quicker being dash charged all the time.
saw 60 percent at 35 minutes and 38 seconds, which is more or less in line with what OnePlus claims
Incredibly fast compared to my old Honor 8. One example I have is the first charge I did 5 days ago when I had bought it at a pop-up event here in Sweden. I had used it for about 1-2 hours with the screen on when I was setting it up and trying out the phone. Then when I plugged it in, it went from 36% to 75% in just 24 minutes. That's insanely fast
I've also noticed that just like OnePlus claims, the phone basically charges at the same speed with the screen on as if I would have had the screen off.
Bäcker said:
Still, I would only recommend using that feature if there is a real benefit - i.e. time is of the essence. The battery will age quicker being dash charged all the time.
Click to expand...
Click to collapse
Can you provide any factual basis for this statement? Research or articles from established professionals in the field of battery charging?
Everything I've read from reliable sources state that the biggest impact on battery longevity is temperature. Repeated heating (or extreme cooling for that matter) will accelerate the "aging" process, as you put it. OnePlus has actually solved this problem by offloading the energy conversion that causes heat to the power brick, leaving the phone cool during charging (pretty ingenious). I've also read that not always charging the battery fully to 100% can prolong longevity, which is why you get charging strategies on laptops that will stop charging at 80% or 60% if you leave your laptop plugged in 24/7.
Point being, the ONLY way to slowly charge this device would be to use a third party charger and/or cable.
The reason I ask this, is that the manufacturer, OnePlus, clearly states in their documentation that comes with the phone or dash chargers to ONLY use the charger and cable that came with the phone.
Please charge the OnePlus Dash device only with the official Dash Power Adapter and Dash Type-C Cable. Using unauthorized adapter can be dangerous and may void your warranty.
Click to expand...
Click to collapse
I'm not completely opposed to the idea that this could just be a marketing ploy to get you to buy their own adapter and accessories, but again just want to know if there's any substantial proof that fast charging, by itself, degrades the battery faster, of if it's just a case of incorrect tribal knowledge.
Thanks.
You are correct that the rate of charge and discharge alone are not the only deciding factors on lipo life and certainly not the most decisive ones.
Excessive heat, especially on high charge levels, is the biggest factor for increased aging.
As you mentioned extreme charging levels (completely empty or full) will also contribute to faster aging, albeit the impact is not that extreme for these low current-draw Lipos used in our phones (as opposed to high-drain Lipos for instance).
Discharge and Charge at high rates will also contribute to the speed of aging, but not as much as heat.
When a lipo spends most of its time one medium charging levels at moderate temperatures and is only charged and discharged with low rates on it will have the longest service life.
This is common for all Lipos, just how much a low or high rate is for that particular battery differs (low drain, high capacity VS high drain, low capacity cell)
With Lipos everything is a compromise. Max and min voltages, max temperatures, max draw are values the manufacturer has chosen as the best compromise to reach the intended MTBF. All these numbers are not physical absolute barriers.
Charges 0-100% in 1hr 30 mins
Second place after SuperCharge (even first gen) from Huawei. Much better than QC 3.0
Klanac89 said:
Second place after SuperCharge (even first gen) from Huawei. Much better than QC 3.0
Click to expand...
Click to collapse
Nope. Super VOOC (OPPO) is hands down the fastest!
Gustav Karlsson said:
Nope. Super VOOC (OPPO) is hands down the fastest!
Click to expand...
Click to collapse
First of all, how many device support Super VOOC? How many device you can buy outside China with VOOC?
Super VOOC is 50W, the same like Huaweis SuperCharge 2.
Did you test SuperCharge 2 or VOOC?
My OP6T charges up to 100% in 1hr 22mins, so I don't charge overnight anymore. Go to sleep on 40% and charge in the morning
The combo of battery life and crazy fast charging is for the first time breaking me of the "plug it in overnight" habit that I have had since my first cell phone over a decade ago. I can keep my charger at my desk, plug it in for half an hour, and be at 100% with almost no chance of running out before the next morning. That means fewer vampire chargers around the house wasting power, and fewer charge cycles lost leaving the phone plugged in long after it's full. I wish I had swapped to OnePlus sooner - I think I have finally found a phone maker to call my favorite.
The charging Speed with "Dash charge" is amazing.
Within few minutes the battery is from 0% to over 50%!
Generelly I can only say: Amazing battery life. The best I ever had with a phone (except Nokia 3310).
I started to charge when the battery was 5%. It took around 1 hour 20 mins. I can say this to be quite faster when compared to the devices I have used previously, that too when the size of the battery is much bigger than the previous phones.
Illrigger said:
The combo of battery life and crazy fast charging is for the first time breaking me of the "plug it in overnight" habit that I have had since my first cell phone over a decade ago. I can keep my charger at my desk, plug it in for half an hour, and be at 100% with almost no chance of running out before the next morning. That means fewer vampire chargers around the house wasting power, and fewer charge cycles lost leaving the phone plugged in long after it's full. I wish I had swapped to OnePlus sooner - I think I have finally found a phone maker to call my favorite.
Click to expand...
Click to collapse
The incredibly fast charging, coupled with the insane battery life (especially in dark mode) has made me totally OK with no wireless charging. I used to leave my phone on the charging pad at my desk most of the day, and on my nightstand charging pad overnight. I never had to worry about charging at all and plugged in maybe 20 times max over the last two years with my Note5. I said I'd never buy a phone without wireless charging, but the $350 or so I got for my Note5 exchange for this phone was just too tempting to overlook, particularly if it set up my family for the next two to three years (our current phones didn't have band 71 and Samsung said no more security updates). The only thing I was really worried about was wireless charging and whether or not the battery life and dash charging would be enough for me to overcome range anxiety.
It has.
So I'm thinking of keeping my dash charger at home ,and my 30w aukey charger at work ,I take it this will be ok to use ?
Gustav Karlsson said:
Nope. Super VOOC (OPPO) is hands down the fastest!
Click to expand...
Click to collapse
mate 20 pro, charges 4200 mAh in 1 hour.
Shady282 said:
mate 20 pro, charges 4200 mAh in 1 hour.
Click to expand...
Click to collapse
Oppo Find X (Lamborghini edition) charges 3300 mAh in 35 min...
combat goofwing said:
So I'm thinking of keeping my dash charger at home ,and my 30w aukey charger at work ,I take it this will be ok to use ?
Click to expand...
Click to collapse
It should be. If you are starting from full in the morning I doubt you will even need the charger are work except for very rare instances. I have gotten 7 hours SOT that was mostly gaming on this thing, moderate use you can easily get 24 hours, light use around 48.