Database Info

[Q] leaving the Transformer connected to the charger good or bad?

Hello everyone
I was wondering if its ok to leave the transformer connected to the charger.
Is it like the Evo with trickle down when it reaches 100%
I dont want to over charge it. If it were my laptop i would disconnect the battery at full charge. But its not possible to do that with the transformer.
I want to keep my cycle count low and prevent over charing.
I also wonder what happens in a few years when the battery is shot...

Charging is what damages Li-Ion batteries... I'd recommend not keeping it on the charger all the time. Android will purposely not keep the battery at 100% to help avoid some damage.
Li-ion prefer to be around 20-80% charge.

When battery is 100% and you keep the charger connected, heat will begin to build up and eventually you will kill your battery.
I'd do as with a notebook: charge till 100%, then remove battery or charger (in case of the tablet charger ) . Then use your tablet and recharge when needed / desired. And from time to time a full charge / discharge cycle won't do any harm.
Just my 2 cents.
Regards.

These tablets don't automatically recognize when it's fully charged and turn off the charging?

Ravynmagi said:
These tablets don't automatically recognize when it's fully charged and turn off the charging?
Click to expand...
Click to collapse
They do. There are other threads asking why thier TF's don't show 100% when unplgged from the charger. Same as it does on my Evo.

I think pretty much every modern device recognizes a full charge and responds accordingly. In fact, MacBooks will throttle performance if the battery ISN'T kept in while the system is running on A/C.
Heat will damage a battery, but it's not heat from charging but heat from operation. If a notebook is poorly designed and the battery is near a heat source, then removing the battery might be a good idea (except with the aforementioned MacBooks), but that's independent of the charging issue.
I think it's fine to keep it plugged in. These devices are smart enough to manage such things. Of course, the TF's charging cable's so short it's hard to use when plugged in, but that's a different issue entirely.

CalvinH said:
When battery is 100% and you keep the charger connected, heat will begin to build up and eventually you will kill your battery.
I'd do as with a notebook: charge till 100%, then remove battery or charger (in case of the tablet charger ) . Then use your tablet and recharge when needed / desired. And from time to time a full charge / discharge cycle won't do any harm.
Just my 2 cents.
Regards.
Click to expand...
Click to collapse
From what I understand this process cannot and will not kill the battery. This did happen in the old type of batteries with the ,emory effect but these new batteries and the OS's management system for charging does not allow the battery to be killed.
it will heat up and that would happen as there is a flow of electricity but not to a level that would kill the battery.
Cheers

IS it normal to go from 4% battery to 99% in under 3 hours ?
I thought this was supposed to take 8 hours to charge.
Cheers,
gpearson1968

gpearson1968 said:
IS it normal to go from 4% battery to 99% in under 3 hours ?
I thought this was supposed to take 8 hours to charge.
Cheers,
gpearson1968
Click to expand...
Click to collapse
Yes that's normal. It's meant to take about 3hrs.

Thanks guys...
Still dont know about it. Because I think its like my EVO and technology got so good that my battery is protected.
I really dont want my transformer to become a expensive paper weight or non-mobile because after a few years it has 45 mins battery life.

I've got the first full charge and full depletion done. Is it ok to use while charging now as long as I fully charge and fully deplete it a couple more times?

error12 said:
Thanks guys...
Still dont know about it. Because I think its like my EVO and technology got so good that my battery is protected.
I really dont want my transformer to become a expensive paper weight or non-mobile because after a few years it has 45 mins battery life.
Click to expand...
Click to collapse
batteries will degrade over time....would you be keeping this tablet for over 2-3 years? a simple battery change could work if ever needed

I am no expert, but I have spent some time searching around the internet looking for information on the best methods for improving the life of a battery. Most of the information I have found said it is bad to completely discharge a Li-polymer battery. The articarles stated it was best to charge the battery when it reaches 20% to avoid shortening its life.
Sent from my DROIDX using XDA App

Batteries are like muscles - they like to be exercised.
Leaving the unit plugged in WILL NOT HURT YOUR BATTERY. Period. The charging circuitry in modern devices is smart enough to cut current to the battery once it has reached a certain level of resistance.
Batteries do not like being deeply discharged. Most devices will shut off before the battery gets too deeply discharged, but it's never a good idea to tempt fate by running it until the device shuts off.
What really determines a battery's life is the number of cycles it has been put through. A cycle would be a full charge followed by a full (or to a lower end threshold) discharge.
The old original Lithium Ion batteries used in laptops would usually last about 300 full cycles or so - about a year if you used it on the battery every day. Partial discharges of course only count as fractions of a cycle.
Given the life of these types of devices, considering we'll likely upgrade to the next big thing in a year or so, I don't think anyone here will come close to 'wearing out' a battery.

EMINENT1 said:
I've got the first full charge and full depletion done. Is it ok to use while charging now as long as I fully charge and fully deplete it a couple more times?
Click to expand...
Click to collapse
As stated, these are Li-Ion batteries, and they do not need to be trained. The only reason you might need to do any training is to calibrate Android's understanding of the battery (although I doubt you need to do a full discharge for that, either).
It's not going to suddenly kill it, but it will over time hurt your battery's life.

I went ahead and did a full discharge/charge cycle, but only because Asus said to do so in the manual. Maybe the copywriter just copied/pasted from a circa 1990's manual for a device with a NiCd battery, but I figured if they're suggesting it, I might as well do it.

Keep TF always in dock?

Hello all,
I am still a bit confused as to how the dock actually works. Since i got my dock this afteroon i charged it up until the light was green with the TF in it and it has been that way ever since; I have no undocked the TF
Is this going to wear out the dock battery quicker? How can i tell? Is there a way to turn the dock off. I find it strange that the owners manual on such a new piece of technology is so limited in scope, it just tells you how to dock/undock it and charge it

It's been stated that the dock battery will charge the tablet battery while the tablet is connected to it.
Of course, when the tablet battery is topped off, the dock battery doesn't charge it. At that point, I'd assume the unit runs off of the dock battery until it's depleted, then runs off of the tablet battery. Once depleted (or discharged a bit, and I'm not sure as I don't have my dock yet) and connected to AC power, I'd suspect the tablet will charge first, then the dock battery.
BTW, did the dock come with a power supply and cable, or do you have to use the one the tablet came with?

FrayAdjacent said:
It's been stated that the dock battery will charge the tablet battery while the tablet is connected to it.
Of course, when the tablet battery is topped off, the dock battery doesn't charge it. At that point, I'd assume the unit runs off of the dock battery until it's depleted, then runs off of the tablet battery. Once depleted (or discharged a bit, and I'm not sure as I don't have my dock yet) and connected to AC power, I'd suspect the tablet will charge first, then the dock battery.
BTW, did the dock come with a power supply and cable, or do you have to use the one the tablet came with?
Click to expand...
Click to collapse
no cable with it.
I guess they assume youll be charging them together. the dock bought the tablet from 80% to 100% and it self to 95% in about 40 minutes with the ac plugged in.
Your description of how it works seems to be what i was thinking because the tablet shows the lighting bolt on the tablet even when its at 100% is that good for the battery? Seems to be like the tf loses a TINY bit of charge and it just gains it back from the dock and this just keeps going on.

it's harmless.

seshmaru said:
it's harmless.
Click to expand...
Click to collapse
all i needed to know. I assume i can use the notification light on the dock to know when its running low.
I heard before that the dock doesn't actually turn itself off; that is if its not connected to the tablet, so it drains its battery while not doing anything. I assume if this is true there would be some kind of firmware that puts it in a very low power state until the dock recognizes something is attached to it.

biggiephat said:
all i needed to know. I assume i can use the notification light on the dock to know when its running low.
I heard before that the dock doesn't actually turn itself off; that is if its not connected to the tablet, so it drains its battery while not doing anything. I assume if this is true there would be some kind of firmware that puts it in a very low power state until the dock recognizes something is attached to it.
Click to expand...
Click to collapse
Actually it is true, and yes it goes into a low power state, although asus has said it's not low enough. They're going to release a firmware update to put the dock into deep sleep when not connected in the future instead of regular sleep which drains about at 50% of the tablet does when the tab is on standby. Of course this update will also bring up the battery power of the dock to about 9 hours since it has the same battery as the tablet.

Sucks that they don't give you another power supply and cable with the dock. I'm gonna have to buy at least one extra. I plugged the cable into my Nook Color charger just to see what it would do. Nope. Won't charge. (at least with the device on... perhaps it will with the device off?)
This means we're going to have to buy proprietary chargers and cables... and I don't think anyone has any yet.
As for the OP, I concur, don't worry about the dock battery. Batteries are like muscles- they like to be used, and don't like to be idle all the time.
As a matter of practice, I try to drain my devices about once a month (run them down to the battery warning, usually 20% or so) and then charge them up again.

http://arstechnica.com/gadgets/news...-is-the-best-way-to-use-an-li-ion-battery.ars has a good description of how Li battries work. Main points are
One of the worst things you can do to a Li-ion battery is to run it out completely all the time. Full discharges put a lot of strain on the battery, and it's much better practice to do shallow discharges to no lower than 20 percent. In a way, this is like people running for exercise— running a few miles a day is fine, but running a marathon every day is generally not sustainable. If your Li-ion powered device is running out of juice on a daily basis, you're decreasing its overall useful lifespan, and should probably work some charging stations into your day or change your devices' settings so that it's not churning through its battery so quickly.
On the other end of the spectrum, keeping a Li-ion battery fully charged is not good for it either. This isn't because Li-ion batteries can get "overcharged" (something that people used to worry about in The Olden Days of portable computers), but a Li-ion battery that doesn't get used will suffer from capacity loss, meaning that it won't be able to hold as much charge and power your gadgets for as long. Extremely shallow discharges of only a couple percent are also not enough to keep a Li-ion battery in practice, so if you're going to pull the plug, let the battery run down for a little bit.
From this you won't harm it through overcharging by leaving it in the dock but you should remove it occasionally and let it run down a bit.

I was thinking about this the other day and I think my planned usage won't be very good for the dock's battery. I was planning to take it to work with me during the day as my second system, and not worry about taking a power cable with me. That is, I figured the dock would power the tablet throughout the day and then when I returned home I'd have plenty of power left for using the tablet by itself in the evening.
However, I think this will basically drain the dock battery pretty completely every day, representing a full discharge cycle. That means the dock battery's lifespan will be severely impacted, even as the battery in the tablet is probably made to last longer (it'll see mostly dips to 70% or so each day, and then recharges).
Maybe I'll have to get a second power cable for work after all, just to avoid killing the dock's battery.

wynand32 said:
I was thinking about this the other day and I think my planned usage won't be very good for the dock's battery. I was planning to take it to work with me during the day as my second system, and not worry about taking a power cable with me. That is, I figured the dock would power the tablet throughout the day and then when I returned home I'd have plenty of power left for using the tablet by itself in the evening.
However, I think this will basically drain the dock battery pretty completely every day, representing a full discharge cycle. That means the dock battery's lifespan will be severely impacted, even as the battery in the tablet is probably made to last longer (it'll see mostly dips to 70% or so each day, and then recharges).
Maybe I'll have to get a second power cable for work after all, just to avoid killing the dock's battery.
Click to expand...
Click to collapse
i just checked my tablet on the dock today its been 24 since its been on there and i haven't touched it and now the battery is down to 99% and not charging as it was before did the dock really die that quick?

Battery drain with dock

Seems this is back again with ICS.
Anyone else having problems as well?

I hate to say it, but it seems so, at least based on my first measurements. Back last year, during the earlier round, I took quite a few measurements before and after having the dock updated. When it was over, I saw aggregate battery drain of the tablet and dock in idle as nominally around 0.2-0.3% per hour. A couple of nights ago, with ICS, I measured about 10 times that amount, approximately 2% per hour.
To be fair, I'm in the middle of dealing with the instability and reboot problem on ICS, and I'm hoping resolution of that problem will eliminate the new, apparent battery drain increase. My one night measurement didn't include a spontaneous reboot, but that night it showed about half time deep sleep, and some level of activity the rest of the night.

With me last night my tablet had about 10% battery and the dock had 85% battery.
Leave the tablet docked overnight (with Airplane mode and wifi policy set to never for keeping wifi on during sleep).
Check this morning and the tablet battery is reading 69% and the dock battery is down to 3%.....
I also have the MoblieDock power saving enabled.

Sometimes i leave my tablet with dock at home when i go to school and when I'm back the tablet is powered off and it won't turn on unless i plug in the charger. The battery completely drains out to 0% even though it was charged about 40-50% when left
Sent from my Transformer TF101 using Tapatalk

browngeek said:
With me last night my tablet had about 10% battery and the dock had 85% battery.
Leave the tablet docked overnight (with Airplane mode and wifi policy set to never for keeping wifi on during sleep).
Check this morning and the tablet battery is reading 69% and the dock battery is down to 3%.....
I also have the MoblieDock power saving enabled.
Click to expand...
Click to collapse
I'm not sure if you are pleased or concerned about your readings, but they look pretty good to me. I assume that you had been running the tablet separate from the dock earlier, so that it was able to run down to 10%, while the dock still had 85%. That condition should never have occurred if the tablet and dock were being used together.
As I see it, the tablet battery contains approximately 60% of the combined capacity, and the dock about 40%, so I would factor any change in the tablet battery by 0.6 and by 0.4 for the dock. The tab battery went from 10% to 69% overnight (drawing charge from the dock battery), for a net increase of 59%, or +35.4% of total capacity. The dock battery discharged from 85% to 3% for a net decrease of 82%, or -32.8% of overall capacity, so that combining the two (35.4%-32.8%) the overall battery somehow increased its charge by 2.6%, which is highly unlikely, but you are using approximations, so maybe the actual numbers were a few percent off, one way or another, and there most likely was a very small loss in battery power overnight.
Does that jibe with your conclusion, or did you interpret the results differently?
Sent from my Transformer TF101 using Tapatalk

I left my TF & dock overnnight in Airplane mode, and my battery depletion was about 0.2% per hour, back down to the pre-ICS level I had observed before. eboot Logger did show that I experienced a spontaneous, successful reboot in the middle of the night, so apparently having the radios disabled is no guarantee of protection from the reboot problem, but at least the battery loss was acceptable. I went ahead and set the Wi-Fi advanced setting to disable when screen is off, except when on charger, to see it that will keep the idle battery discharge in check.
I consider any of these actions as temporary workarounds, until ASUS fixes the underlying problems. We should not have to be gerrymandering our systems by trial and error to protect ourselves from dead batteries on idle systems.
Sent from my Transformer TF101 using Tapatalk

vicw said:
I'm not sure if you are pleased or concerned about your readings, but they look pretty good to me. I assume that you had been running the tablet separate from the dock earlier, so that it was able to run down to 10%, while the dock still had 85%. That condition should never have occurred if the tablet and dock were being used together.
As I see it, the tablet battery contains approximately 60% of the combined capacity, and the dock about 40%, so I would factor any change in the tablet battery by 0.6 and by 0.4 for the dock. The tab battery went from 10% to 69% overnight (drawing charge from the dock battery), for a net increase of 59%, or +35.4% of total capacity. The dock battery discharged from 85% to 3% for a net decrease of 82%, or -32.8% of overall capacity, so that combining the two (35.4%-32.8%) the overall battery somehow increased its charge by 2.6%, which is highly unlikely, but you are using approximations, so maybe the actual numbers were a few percent off, one way or another, and there most likely was a very small loss in battery power overnight.
Does that jibe with your conclusion, or did you interpret the results differently?
Sent from my Transformer TF101 using Tapatalk
Click to expand...
Click to collapse
But I thought the whole idea of leaving the TF-101 on standby with the dock in is that the dock doesn't not draw battery charge to the tablet, its only supposed to do that when you are actually using the tablet (with it docked)? Please correct me if I am wrong.

I've even had my dock completely drain in 2 hours while the tablet is supposedly sleeping. Maybe that was a fluke though, the drain seems to be in line wit Honeycomb most of the time...
Sent from my Transformer TF101 using Tapatalk

'best' way to charge.?

hi friends,
got my tf300 32gb + keyboard dock from best buy, US...rooted it and updated it to .29 f/w......running excellent...no issues
the first charge was done for 8hrs with tab+dock...it is still running great now after 2 days with still 30% juice remaining on tablet and 0% on dock (i store the tab connected to dock, so the tab is slurping off the juice from the dock)
now i want to know ..what is the 'best' way to keep charging this awesome machine...(i know there might not be an 'ideal' way..)
should i wait till the charge in tab goes to less than 10% and then charge it with dock or should i charge them seperately, ensuring the dock doesnot reach 0% ?
how do you guys do it?..just wanna know different thoughts

I just use mine throughout the day, starting around 7:30am when I get up and ending at 10:00 when I plug it in by my bed.
By that time its usually around 45-50% on the tablet and 0% on the dock but keep in mind that I use this as my primary means to access the internet especially at my school cuz the computers suck. It then charges overnight and by the morning its full again.
I don't know if this is the most battery effiecent (ie: long term strength) but it works ok for me and I've never had any problems with other devices that have used the same basic schedule.
Sent from my ASUS Transformer Pad TF300T

SilentStormer said:
I just use mine throughout the day, starting around 7:30am when I get up and ending at 10:00 when I plug it in by my bed.
By that time its usually around 45-50% on the tablet and 0% on the dock but keep in mind that I use this as my primary means to access the internet especially at my school cuz the computers suck. It then charges overnight and by the morning its full again.
I don't know if this is the most battery effiecent (ie: long term strength) but it works ok for me and I've never had any problems with other devices that have used the same basic schedule.
Sent from my ASUS Transformer Pad TF300T
Click to expand...
Click to collapse
The worst part about this practice is letting the dock run all the way down to 0%, because that means a full charge cycle every day. Charging the tablet at 50% or so is fine, though. If you could figure out some way to charge the dock at the same 50%, you'd be in good shape.
Might be impossible given your usage patterns, though. I'd just expect the dock battery to wear out much faster than the tablet's.

Don't think there's a practical way of avoiding running the dock to 0%.

I've read thousands of posts on the ideal way to treat modern (Li-ish) batteries, and so far I lean towards keeping them as charged as possible.
That is - they wear out faster if the're discharged alot to for instance 0%.
The old "discharge to train them" or whatever seems to be either an outdated practice or a myth, and - if I've got it right - outright bad for modern batteries. Which means some companies most likely applaud the practice to sell more stuff.
But I'm not an expert (then again - very few people seem to be).

It's an outdated practice related to the old NiMH batteries from the 80s. If you didn't discharge NiMH batteries to 0%, then whatever percentage you charged it at would be the new 0%. For instance, if you were to plug it in at 50% one day, your battery capacity would automatically be cut in half because the battery would think 50% was "empty". NiMH batteries were eventually fixed, but even then, and even today with Li-Ion batteries, some people think they should be discharged completely.
Also, keeping Li-Ion batteries completely charged all the time is equally as bad as constantly letting them drain completely. Personally, I charge my tablet when it warns me that my battery is low, around 14%.

EndlessDissent said:
Also, keeping Li-Ion batteries completely charged all the time is equally as bad as constantly letting them drain completely. Personally, I charge my tablet when it warns me that my battery is low, around 14%.
Click to expand...
Click to collapse
"as charged as possible" combined with a very mobile device = charging at 20-50% for me.

When I plug my tablet into the fully charged dock, and the tablet battery is below 60%, it discharges the full dock battery within 2 hours. In order to avoid fully discharging the dock as mentioned above, one would be constrained to only 2 hours of netbook type use (or maybe a few hours more if the tablet is fully charged) which defeats the whole benefit of 10+ hours of battery life when using with the dock.
Given this, I believe the doc battery must be able to withstand regular full battery discharges, otherwise Asus probably would have devised a different algorithm for charging.

Dock charging after V9.4.5.26 firmware update

Anyone else seem to have dock to tablet charging change in behavior after the V9.4.5.26 firmware update?
Before the current firmware I recall the dock topping off my tablet battery after the Infinity was left idle for a while. Now it seems the dock at best is only slowing the tablet's battery drain. If I reboot the tablet the dock seems to make more progress towards charging the tablet battery closer to full.
I don't quite know if I'm misremembering the old behavior, or this was a firmware change, or I should be concerned about a faulty dock to tablet connection.

sandymacjr said:
Anyone else seem to have dock to tablet charging change in behavior after the V9.4.5.26 firmware update?
Before the current firmware I recall the dock topping off my tablet battery after the Infinity was left idle for a while. Now it seems the dock at best is only slowing the tablet's battery drain. If I reboot the tablet the dock seems to make more progress towards charging the tablet battery closer to full.
I don't quite know if I'm misremembering the old behavior, or this was a firmware change, or I should be concerned about a faulty dock to tablet connection.
Click to expand...
Click to collapse
Mine beheaves just like yours, but I'm still on .22
When the tablet's battery is empty and I plug in the Dock it loads the tablet
but when I put the tablet with the dock together when both of them are about 70 % then the dock isn't loading the tablet
---------- Post added at 05:07 PM ---------- Previous post was at 04:17 PM ----------
I just found out that the dock has started to charge the tablet when the tablet's battery was going under about 60%

Same behavior here
no reason dock should have charge if tablet isn't full. charge in dock is pointless.

My unreliable understanding is a 0% empty or 100% full lithium battery will have a shorter usable life span than a lithium battery maintained around 75%. I can understand that trade off for the dock battery if that is what is happening.
gottahavit said:
no reason dock should have charge if tablet isn't full. charge in dock is pointless.
Click to expand...
Click to collapse

Last night I noticed that the tablet says "charging" while in the dock, and the dock depletes. It seemed pretty slow and the dock seemed to drain reasonably quickly. From what I've read, its supposed to drain both at a slower rate.
Personally, I like the idea to have the dock charge the tablet. It just makes more sense.

Mine was still not charging the tablet at 76%, now I docked it under 66% and it's charging, so I believe it goes on somewhere around 70. I think it was somewhat sooner under .21 and .22, but after installing SwiftKey (crypto-ad) I'm rarely using the dock when not using the shell (but hey, I'm on holiday!).
Edit: Stopped charging at 90% (the dock is 60% now, so ~25:40 ratio, btw), seems reasonable.

sandymacjr said:
My unreliable understanding is a 0% empty or 100% full lithium battery will have a shorter usable life span than a lithium battery maintained around 75%. I can understand that trade off for the dock battery if that is what is happening.
Click to expand...
Click to collapse
Then no charger should ever charge past 75 %. Now if you want to argue not depleting the dock past 10% i would buy it.

sandymacjr said:
My unreliable understanding is a 0% empty or 100% full lithium battery will have a shorter usable life span than a lithium battery maintained around 75%. I can understand that trade off for the dock battery if that is what is happening.
Click to expand...
Click to collapse
It does make sense, switching charging off and letting the battery drain partly allows the battery in the tablet to have a longer life span. It usually let's it drop 20% or so and then charges it for a certain amount. If you keep charging from 90% to 100% over and over, it depletes the life span of the tablet's battery.
Sent from my ASUS Transformer Pad TF700T using xda app-developers app

KilerG said:
It does make sense, switching charging off and letting the battery drain partly allows the battery in the tablet to have a longer life span. It usually let's it drop 20% or so and then charges it for a certain amount. If you keep charging from 90% to 100% over and over, it depletes the life span of the tablet's battery.
Sent from my ASUS Transformer Pad TF700T using xda app-developers app
Click to expand...
Click to collapse
With Lithium Ion though, that shouldn't be an issue from what I understand. NiCad's, and to a MUCH lesser degre NiMh's will get that memory effect, but Li-ion's are immune to it, in fact they do better when kept charged up.

californiarailroader said:
With Lithium Ion though, that shouldn't be an issue from what I understand. NiCad's, and to a MUCH lesser degre NiMh's will get that memory effect, but Li-ion's are immune to it, in fact they do better when kept charged up.
Click to expand...
Click to collapse
That is true, Li-Ions are much better off staying between 40 to 80% and don't have the dreaded memory effect of NiCd and NiMH. However, when you get close to 100% when charging the voltage is also very high, which can shorten the lifetime of the battery in the long run. That's also what KilerG is saying.
It's better for the battery to just let it discharge a bit, then charge it up again. Maintenance charging it at 100% will require a lot of juice from the dock when the tablet is in use. The charge efficiency is greatly lowered when above ~80% since you need to continue increasing the voltage, but decrease the current to avoid overheating and damaging it.
My dock is currently at 78% battery while the tablet is at 77%. It's been on battery power for about 2,5 days now, I've only used it for a short time lately as I've been busy with other things.
Last time I took it off AC and it was more actively used, the dock depleted more quickly while the tablet was being topped off by the dock every now and then. Gives the tablet a lot longer usage, although you could end up with an empty dock while the tablet is still running. That's fine with me, the dock isn't much use without the tablet.
Edit: Actually, the battery indicator wasn't updating it seems. I undocked and docked again and the numbers went from 78% and 77% (dock and tablet) to 63% and 85%. Not sure why the battery status isn't updating properly. Might just be a one-time thing.

From the Asus forum:
http://www.transformerforums.com/fo...attery-related-matters-transformer-range.html
Excerpt:
TF201/TF300/TF700
* The charger charges the docked combo all together.
* When fully charged, the tablet uses the charge first, then the dock charges the tablet. The idea being that the dock battery will be depleted while maintaining the tablet battery. See below...
The way the combo works is that the dock does not charge the tablet continuously. I believe the percentages are along the following lines..
Dock 100%
Tablet 100%
Tablet uses charge until the level is around 70%. At this point the dock will recharge the tablet back up to around 90%, if the tablet is not being used.
If the tablet is being used, then the dock "powers" the tablet, balancing the charge rate with a direct bias to ensure that the dock will eventually drop to 3-5% with the tablet at around 90%.
The dock shouldn't allow itself to become any more discharged than 3-5% & neither should the tablet. Android will warn you when the tablet drops to 14%.
The dock will still continue to function until the tablet shuts off.
----------------------------
However, this is not my experience, which is why I was researching it in the first place. Dock charging behavior is inconsistent. I started seeing that the dock was no longer fully charging the pad w/o a cold boot recently (I'm still on ICS, rooted). Then it would develop the problem again after a short time, even when plugged into AC. Right now I'm plugged into AC. At start my dock had no charge and the tablet had about 60%. The AC charged the dock and the dock passed charge to the tablet until the tablet had 100% charge - correct behavior, I believe, since this is what it did when brand new (it's still quite new). Many have posted about the dock not charging the pad over time. I think there's a hardware issue of some kind, or system software problem since it temporarily will correct after a cold reboot. Or maybe there's a software conflict. I've been uninstalling stuff to free memory.

Einride said:
Edit: Actually, the battery indicator wasn't updating it seems. I undocked and docked again and the numbers went from 78% and 77% (dock and tablet) to 63% and 85%. Not sure why the battery status isn't updating properly. Might just be a one-time thing.
Click to expand...
Click to collapse
I'm having this problem, too. After charging both batteries to 100%, I unplugged from AC, and I've been using the pad for a couple of hours. The battery indicators still say 100%. I think this may be a hardware problem (or an API problem) because Dual Battery Widget reports the same. Undocking and redocking did not help. I suspect only a cold reboot will help. Perhaps my prior problem was a battery indicator problem, and not a charging problem, as it seemed.