[helsinki98]

I have noticed that since I have been using the official rapid dock charger my battery has not been lasting as long when compared to the charger I was supplied with.
The charging time is much shorter, currently charging at close to 10volts before only at 2.5ish volts, which is nice but the decrease in use time while not connected is a drawback.

I'm not sure if this battery is similar to batteries i have used before but i found using a 'slow charge' at less volts would provide a longer operational time period compared to a 'rapid charge' which would be quicker but not lost as long.

Has any one noticed the battery goes down much faster after a charge from the rapid charger compared to the boxed charger which charges at a low voltage?

To note, my battery health hasn't changed and to my knowledge nothing else has other then a few other apps being installed.

[peter9477]

The rapid charger will not (should not) decrease the charge like that. I suspect you're not actually waiting until it's fully charged though: do you just wait until you see 100%, or do you wait until it's actually completed charging?

Also, have you tried doing a drain test on it?

It's likely that what you're seeing is a miscalibration of the battery level, not an actual decrease in the charge. That is, either it's not really full when it says 100%, or it's not really empty when it reads 0%. Doing the drain test can tell you the truth of the matter, and should also result in it resetting the health a short time after (within about one recharge cycle, but not immediately).

If you really have truly got a shorter battery life now, the health should drop to reflect that. If it doesn't, I think the problem is somehow your technique for measuring how long the battery lasts.

[jafobabe]

The charging pins on the dock may not be seated correctly too. Get the Battery Guru App in AppWorld and you will be able to monitor your battery usage.

[pluke100]

Great app peter9477.

do you please give us a few tips (or link us to previous threads) about the best way to threat the battery? Example: Should i let the battery reach levels below 20% before i charge or i'm doing it more harm by doing that?

Also does rapid charging increase the overall battery life or it won't make any difference on the future performance of the battery compared to the normal charger?

[helsinki98]

Thanks for the replies. I allready have the battery guru app, was the first I purchased!

I leave my playbook on the rapid charging dock all day, the charging icon usually shows the plug symbol and not the lightning symbol when I take it off. I'm currently charging up to 100% with plug symbol then will do a battery drain test overnight.

I exported the .csv of the battery and tried to put it into a graph but it's been so long since I have used excell that I can't remember how to properly. (being able to scroll through the graph in the app would be a nice feature and compare levels).

An example of the battery performance decrease is that When I wen't to a lecture earlier today I packed my playbook (starting at 100% plug symbol) and when I took it out two hours later the level being shown on the battery guru app was around 91% Wifi had been on but not connected and the screen hadn't been on either. Not much of a comparison but when I was charging with the standard charger I left my playbook off charge overnight connected to an active wifi and found their to be a 4% battery drop in roughly 8/9 hours.

From my memory the decrease of the line (on the battery app) is greater since I have been using the rapid charger compared to the standard charger while I have left the playbook idol off charge.

I just had a quick look at the pins on the rapid charger and the pin on the left looks shorter then the the other two.

[peter9477]

When was the last time you restarted it? There are known issues (as you're probably aware) with GPS, and possibly WiFi, that can result in increased standby power consumption until you restart it. (And for some, even that doesn't fix the WiFi issue, but you presumably already know you're not a victim of that particular problem since it affects them all the time.)

I wouldn't worry about the charger... as long as it actually charges (and the 10W proves it does) the pin isn't currently causing you a problem. Just to confirm, what voltage does it show when it's around 100% and not currently charging? (That is, on the charger or not, but the Power reading show 0.000W.) Also what's the health again?

If you run Battery Guru during all this, feel free to export the CSV, zip it up (easier for me) and email it to the support email address in App World (or the one you'll find on the web pages if you click the link in the app's menu). I can interpret for you easily enough.

100% down to 91% in 2 hours would be 0.81W average. Battery Guru's log should show that, and it's definitely a problem. In fact, it's very unusual... I can identify most of the types of activity that result in various power levels, like 0.05W, 0.25W, 0.34W, 1.3W, and so on... but 0.81W is a new one if that's what it really was. Screen wasn't on, but that's well over what most other types of activity can consume. Worth investigating further.

I don't currently have any sense this is related to the charger, but anything's possible.

[kubernetes]

A rapid charger should degrade the battery capacity more over the long term (heat), but it shouldn't be dramatic and in a short space of time.

How long have you owned the PB? How much as battery life decreased?

[helsinki98]

I can't honestly recall when I last restarted, This is my third PB so might not have even done a full restart since installing OS 2.0.0.6149. (I installed this before changing chargers)
I can't say I have heard of the GPS or wifi issues, or to my knowledge experienced them.

I try to have the battery guru app running 24/7 I think it used to force close or I absent mindedly closed it but it seems to be open all the time currently.

The charge is currently at 2.61W, it seems that as the battery level increases (93%) the rate of charge also decreases.

Current stats:

Battery 94% Charge: 2.44W
Battery voltage: 4.17V Recharge count: 14
Battery health: 94% Charger type: Cradle

From memory the battery health started out at 100% and dropped to 94% after a few charges.

I will edit the post with the other details when it has finished charging and will send the .csv files.

Edit at 100% plug symbol:

Battery: 100% Charge: 0.00W
Battery voltage: 4.17V Recharge count: 14
Battery health: 94% Charger type: Cradle

[Snoman002]

Do a full drain, all the till it turns off by itself, and then charge overnight using a cell phone charger (not the supplied charger). From there see if the battery performance is better overall, and/or if it better only when slow charging.

I think there are two thing that need to ruled out. One, that the rapid charger isn't just putting a surface charge on the battery. And two, that repeated rapid charging is causing excessive misscalibration of the charge measurement software.

Without doing those two thing everything else is conjecture.

[Innovatology]

I can identify most of the types of activity that result in various power levels, like 0.05W, 0.25W, 0.34W, 1.3W, and so on... but 0.81W is a new one if that's what it really was.

You know your're a geek, don't you Peter? ;-)

[helsinki98]

I have completed the battery drain test and recharged up to 100%, I think the time going from 100% plug symbol to empty was 10-11 hours so it might be something with my wifi causing the battery to go down or i made a mistake.

edit: emailed the results to you peter

[alnamvet68]

I have found, quite by accident, that the battery percentage level changes when I do a re-start. I noticed I had about a 25% charge when I decided to clear the cache, and then backed up and sync'd my PB. When I was done with the DM, I wanted to see if the PB had charged much while connected to the PC, and I had 26%. Anyway, I decided to re-start the PB, and then decided to charge her up with the rapid charger. I checked the battery icon before connecting the charger, and saw I had 37%. Well, I figured the re-start also reset the battery level and proceeded to charge the PB. My best guestimates is that while the PB is in standby/asleep, it will normally discharge at a rate of 2% per hour.

[peter9477]

I have completed the battery drain test and recharged up to 100%, I think the time going from 100% plug symbol to empty was 10-11 hours so it might be something with my wifi causing the battery to go down or i made a mistake.

edit: emailed the results to you peter

Thanks for the data. (OM NOM NOM)

Fascinating results. First, there's no sign of any real problem with the battery. Partly, it seems likely, you've been noticing the effects of the initial recalibration. The health reading actually changed numerous times since you first got it, wobbling its way through 90, 100, 95, 94, 97, 95, 94, 93, and finally settling (for now) at 94%. Your unit is quite new, and this sort of variability shows a nice example of how new units may take a while to "settle down" on a stable health reading, which affects the overall battery level calculation.

The drain test results show you actually ran for 12 hours 24 minutes, which is awesome! The main reason for that, aside from the fact your battery is fine, is that it was using an average power of only 1.488W. If you compare with my reported results for 4 units (three different posts in that thread), you'll see mine all use more power, from 1.665W to 1.977W.

This probably means you're a lucky guy with a newer unit that has a different, lower power, screen or backlight. Or it could mean that in 2.0.0.6149 they tweaked the brightness levels so 0% uses less power... my tests were on earlier versions. I don't think anyone else reported drain test results publicly.

My calculation of your true "health" based on that is 92.3%, so the current estimate by the OS of 94% is pretty accurate.

I'll note one mystery, since others may see this and I'd like to hear from anyone who does.

Your "recharge count" value seems unreliable. After reaching 11, it dropped to 0, climbed to 6, then jumped to 14 and continued regular counting (so far). I don't see that it has affected anything yet, and I honestly doubt it's an issue, but I'd be interested to hear from you in future if you could keep a bit of an eye on it, or submit more data later on, like once you're up to another month of use or so.

My guess with it: the recharge count is likely a value managed by a separate battery microcontroller and, though it's counting correctly, when the value is retrieved by the main CPU it may get scrambled during the transfer. It's probably harmless and you may never see any other sign of it, but keep it in the back of your mind in case anything more significant shows up in the next while. (If it happened on mine, I wouldn't consider it anything more than a curiosity, for now.)

[helsinki98]

wow 12 hours isn't too bad! I'm glad you enjoyed the data

out of the three playbooks I have used, i found this to feel the newest, hard to put my finger on what exactly but the overall unit just felt different, less bulge, no screen issues, non recessed power button, slightly spongy right volume trigger. The date on the box is 081211 which if it's the English date format means 08/12/2011.

I don't recall the recharge amount to have dropped or behave how you described so not sure about that, I have definitely plugged it into charge more then 15 times though.
I'l try and send data once a month if I remember. Thanks for looking over it.