I was browsing the web, and I found something interesting on Wikipedia:
Overcharge up to 5.2 Volts leads to the synthesis of cobalt(IV) oxide, as evidenced by x-ray diffraction
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So this basically means overvolting over 5.2V will make permanent damage to battery (if you look at the other reactions, the Cobalt Oxide can't be returned to original formula, so this will reduce battery LIFE)
Source
Normally phones have a built-in transformer.....
I believe they are talking about battery voltage. Lithium ion batteries are rated at around 3.7v but will have slightly over 4v when they are fully charged. Once your device charges to 100% it stops charging. You cannot overcharge a cell phone, laptop, etc. If you were to apply power directly to the battery contacts which is not recommended then you could overcharge. I belive what that is saying is if you went beyond the ~4v that a lithium battery is at when its charged to 100% and kept charging it up to 5.2v it would get damaged.
This is not talking about chargers which produce a nominal voltage of 5v. I've tested several USB chargers on a voltmeter and they read anywhere from 5.0 to 5.3 volts.
In this case, the USB charger is not so much a charger as a charging source.. the charging circuit is internal in the device and measures battery condition, temperature and voltage and will regulate down the 5V USB supply to the required charging voltage.
Attempting to increase the charging voltage source voltage from the generic USB levels to something higher will simply over-stress the onboard charging circuit to the point that it will fail due to excess dissipation.. and of course, there is no set of circumstances that says attempting to overcharge the battery directly at the terminals can possibly be a good thing
spunker88 said:
This is not talking about chargers which produce a nominal voltage of 5v. I've tested several USB chargers on a voltmeter and they read anywhere from 5.0 to 5.3 volts.
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Related
Hi there
Have you seen this bad boy before?
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I think it has been around for some time (eBay and such), but it was added to the Dealextreme product line this April (link: http://dx.com/p/portable-dual-usb-12000mah-external-battery-power-bank-w-8-charging-adapters-black-184376?utm_source=dx&utm_medium=edm&utm_campaign=20130320new-arrivals-2)
There's a good chance it's not exactly 12000/20000 mAh, but even it's not exactly that, it sure sounds like a pretty good deal anyways.
Do any of you know if this really works intended? Or have you tried it?
Thanks in advance, appreciate it.
I got a 30000mah version of the same box from ebay. Came two days ago, plugged it in to charge, it was alost full when it came. Next day, I opened the box to see what's inside. There were 8 18650 cells and a small usb pcb. So far so good. I hooked up the cells (in packs of 4) to my external battery charger in discharge mode and I got 2500mAh from each 4 pack. That is 5000mAh from both. Not even close to the 30000mAh advertised. It is possible that I got a dud, but my guess is they are recycled laptop cells that just don't hold any charge anymore. I did a full charge/discharge cycle with my external charger and still go the same capacity when going from 3V-4.2V.
Then I tested the range of the USB circuit, and it supplies about 1.6A on the 2.1A port and 1.4A on the 1.0 port. The board shuts off when the battery voltage gets to 3.2V.
In summary - if you get a good set of batteries, expect about 50% of the capacity. If you get bad set, like I did, expect more like 15% of the capacity.
There is a reason a the best panasonic 3400mAh cell costs $14. If these battery banks were really close to 30000mAh in 8 cells, would have cost > $100 just for the cells.
I'm guessing the 12000 has 4 cells and the 20000 has 6 cells with the same USB circuit in them.
I got my Qi pad yesterday in; this one specifically:
http://www.ebay.nl/itm/380712337929
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But the phone gets extremely hot after a short time. When charging by wire it's a little higher than the environment temperature: 22-25C = 71-77F (depends on trickle charge or duration charge of course), but when charging it over the Qi Pad the battery goes up to 42C=107F (and it went hotter the night before, but didn't check the temps back then).
I also notice it really jumps in terms of magnetic field. Now it's a minute I receive about 60 microTeslas of magnetic field, then it's a minute with 200 microTeslas.
Is this a normal for Qi charging? or is there something wrong and rather shouldn't use the pad?
how do you detect how strong your magnetic field is?
convolution said:
how do you detect how strong your magnetic field is?
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https://play.google.com/store/apps/details?id=com.eclipsim.gpsstatus2
Great toolbox honestly, tried a few, foumd this one to be so good I bought the pro version to support the dev. Temps might be a pro-only feature though, not sure.
And lol you already knew the app as you put it in your copied GPS fix guide.
The temperature range you provided is typical of induction charging. My N4 tends to be in the 100-110F range while charging wirelessly. Some heat is generated/energy is lost when transferring energy via induction.
The phone will communicate with the charger to draw the right amount of current depending on the battery state.
wx27 said:
The temperature range you provided is typical of induction charging. My N4 tends to be in the 100-110F range while charging wirelessly. Some heat is generated/energy is lost when transferring energy via induction.
The phone will communicate with the charger to draw the right amount of current depending on the battery state.
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Alright, then I know there is nothing wrong with the pad. It's a cheap chinese one after all.
even with the nexus charging orb, my nexus4 gets hot when using it. i think it's normal for the head to dissipate across the phone and the charger
That's a weird looking foot.
Sent from my Nexus 4 using Tapatalk
i use my gf's samsung qi charger and its the same. i dont know the exact temperature but i usually have to let it sit off charger for a a few seconds before picking it up as the back is extremely hot to touch.
alright, then I know it's normal, but I doubt it's healthy for the battery lifespan :/. Batteries usually degrade a lot when exposed to heat.
Has anyone tried using a non-OEM battery with a Quick Charge 2.0 charger? I've had a TrendON battery as a spare for a while but just decided to swap it with the OEM Samsung battery. After it dropped to roughly 60% I put the phone on an Anker QC 2.0 charger and watched the realtime power with a Portapow Premium DC Multimeter. It was initially drawing 15 watts (9V * 1.67A) and the charging light was green on the charger, indicating fast charging.
After a few minutes I took another look and while the voltage was still at 9V, the current was near zero. The phone was taking in milliwatts of power. I actually let it sit for a few more minutes and then restarted the phone thinking something was off. After restarting I let it sit a few more minutes and then confirmed that the battery percentage wasn't rising. It was stuck around 77%.
I took it off the fast charger and then put it on a "standard" 2A Anker charger and then the battery percentage continued to climb regularly. Really odd.
Anyways I have a graph showing the entire behavior. The green line is battery percentage and the orange line is charge rate as a delta of battery % per hour.
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The fast charger has worked flawlessly in the past when I had the OEM battery installed. I'm guessing that if the phone was drawing 0 watts it had shut down the charging of the battery for one reason or another. Thoughts?
I have been using oem charger with my 2 anker batteries without any issues for almost over a month.
Hmm... just took a peak at my phone and it's actually stalled out at a reported 80% of battery capacity, and this is not on a QC 2.0 charger. This may be a battery issue as I believe battery percentages are calculated relative to battery voltage. I'll reach out to the manufacturer, TrendON, but not holding my breathe as it's been a few months since I purchased it.
Hey everyone.
I noticed today, very unexpectedly, my Mi 16000mAh Power Bank has on it that it has a maximum output of 5.1V/3.6A when only using 1 USB A port. I checked the Mi website and they have the same spec.
Which goes without saying, could it rapid charge? I have a couple of the otherwise dangerous One Plus USB A to C cables, which we know have a resistor that allows a 3A draw, too much for most standard chargers.
I'm going to trust that Xiaomi is not lying about the max 5.1v/3.6A as this is an amazing charger.
Using it right now. Rapid charge via Xiaomi Mi Power Bank USB A confirmed.
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Warning: Don't try this with any other external battery without checking its specifications. If you're going to buy a Mi Power Bank for this function, ensure you buy and official unit as counterfeits exist.
At a minimum you should measure the current draw with something like Ampere (software). Using the 6p and the OnePlus cable you will get "rapid charging" displayed no matter what you plug it into so the screenshot proves nothing really.
I have the exact same powerbank purchased from directly from xiaomi and just did a test with a USB dongle that measures current output. phone was at ~40% battery.
Test 1: with google's usb a-to-c cable that came with the phone: 1.56A
Test 2: with a micro-usb cable w/ usb type-c adapter that shows green on checkR: 1.18A
Sorry man, I don't think there's any way this powerbank is able to output more than 3A or even 2.4A.
I just checked the product page for this powerbank again, and it says Max 5V/3.6A dual output, which I take to mean a max of 1.8A on each port.
Plus, if you've seen the video ackattacker has posted in another thread, you'll realise that the 'charging rapidly' does not reflect how much currently is actually flowing into the phone.
It's still a neat powerbank though, I have always thought it did a pretty good job of recharging on the go.
Hi
I have problem with charging on my U11 with the stock charger and my anker charger with QC3. If i use the normal ports without QC3, I can get 5v and almost 2A.
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But on the voltage bumps up to 7.5v, the current drops drastically to 0.1-0.3a and it wont charge to 100% overnight. I am thinking my phone is having problem as it behave the same on 2 chargers. Any thoughts?
(The picture shows higher current because my phone is on and camera app is running. If phone is off, current is 0.1 to 0.3A)
If the battery is near full you won't get full power. It ramps down to prevent over charging. QC3 is dynamic charging and uses a negotiation routine.
Beamed in by telepathy.
shivadow said:
If the battery is near full you won't get full power. It ramps down to prevent over charging. QC3 is dynamic charging and uses a negotiation routine.
Beamed in by telepathy.
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While what you said is indeed true, that's not exactly the case the OP is experiencing. I say this because he won't charge to full even overnight. Sure, 99% to 100% takes slightly longer, but I believe it's definitely under 5 minutes.
OP, let me share my experience. I have one original HTC charger, one non-original HTC branded charger (half the price of an original, I don't care if it's a fake as long as the quality holds up), and a Xiaomi powerbank that supports two-way QC3.0 (meaning it quick-charges devices but can also be quick-charged itself).
1) The original charger and non-original both work perfectly, quick-charging my HTC U11.
If I charge this Xiaomi powerbank with a normal charger (5V/2A), it also quick-charges my HTC U11 almost as well as the wall chargers.
2) But, if I quick-charge the Xiaomi powerbank itself with a QC3.0 charger (18W), such as the two wall chargers mentioned above, then I have the same issue as you- namely that the powerbank becomes unbearably slow in charging the U11.
3) The way to fix this is to have the powerbank use up all its power then be recharged by a normal charger as in 1). Another way is use the powerbank to charge a normal device, one that doesn't use quick-charge. In both these cases the duration must be for over 2 hours, after which I suspect the "safety mechanism" of the Xiaomi will deactivate and make things normal. Obviously I'm not too happy with this powerbank so will be returning it shortly.
So OP you might wanna try something like charge your phone fully first with non-QC, and the same for your powerbank. Then try charging the phone again using said powerbank.