BlackBerry® PlayBook™

[seth_r]

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knottyrope wrote:

 Lithium batteries have built in protection from heat and evercharging. Once a Lithium battery reaches its fully charged voltage, current flow is stopped and you cant charge it more.

This is the only thing I have to disagree with.  MOST good lithium batteries have this.  ALL lithium batteries do not!!  It is the difference between good ones and cheap knock offs.  Even within the same brand, some do/some don't.

Absent a protection circuit you might risk fire and/or explosion.  A lithium battery explosion is something to behold!!

[cuse165]

My battery is dead will not really charge and when I do get it to it goes from 100% to 5% in lees then 1hr. Even in sleep and lowest power settings.

[seth_r]

There is one myth that misleads people with lithium.  It is NOT good to run a lithium down to 0%.  That said, we really don't know if the item (tablet, phone, etc.) is really at 0%, or if it kicks in early.

The very BEST thing for a lithium is to vary when you charge it.  The same thing applies with a phone.  If its 30%, 50%, 65% or whatever--charge it.

Also, though they don't have memory like NiMH, it can take 2-3 charge/discharge cycles to reach its full operating capacity.  Most charging circuits that show 100% really need another 2-3 hours to top off.  On the other hand, leaving it on a charger more than 10-12 hours after it's done is not good.

[peter9477]

seth_r, you're perpetuating still more myths, at least as far as they apply in the case of the PlayBook.

When the PlayBook shows 0%, the battery still has a voltage around 3.4V, which is far more than the level at which it's "not good" to run a Lithium battery down to. So the RIM engineers made things quite safe for you there...

Charging at different levels (varying the charge) is pointless... as you said (the only thing that was accurate?) they don't have a memory, so there's no reason to worry about the level at which you charge them, even to keep varying it. You can charge every time it reaches 4% if you like, or every time it reaches 80%.

And full operating capacity will be reached with a single charge. With the PlayBook, the charging system slowly decreases the charging current as it approaches "full" (which it defines in terms of the voltage, NOT the percent level). This is one charging circuit that generally doesn't need another few hours.. it goes all the way.

Once it hits 4.2V, it stops charging. You can leave it on the charger for weeks on end, and it will not reconnect the battery to the charging system again... instead, it merely draws power for the device directly from the charger, and leaves the battery alone. Once again, RIM engineers made it quite safe for you.

[dimm0k]

So usually devices run until the battery meter runs pretty close to 0 before shutting down or turning off.  With my PlayBook, running the latest OS, it seems to shut down around the 8 percent mark.  Definitely closer to the 10 mark than 0...  is there a way to better calibrate my battery?

[TroyTempest]

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dimm0k wrote:

So usually devices run until the battery meter runs pretty close to 0 before shutting down or turning off.  With my PlayBook, running the latest OS, it seems to shut down around the 8 percent mark.  Definitely closer to the 10 mark than 0...  is there a way to better calibrate my battery?

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I would say your device is running as designed. Recharge at 10% and never leave on standby overnight without a charger and you will be fine. 

[peter9477]

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dimm0k wrote:

So usually devices run until the battery meter runs pretty close to 0 before shutting down or turning off.  With my PlayBook, running the latest OS, it seems to shut down around the 8 percent mark.  Definitely closer to the 10 mark than 0...  is there a way to better calibrate my battery?

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This post I wrote a long time ago may be of some assistance to you. http://forums.crackberry.com/blackberry-playbook-f222/battery-health-677976/#post6931987

Note that there are some few people whose devices seem incapable of recalibration so that they get below the 8-13% range before shutting down. So far too few of them have actually reported useful information back to me for me to say anything helpful about that. Most who are beyond the first 30-40 recharges have had their devices recalibrate properly and they get down to around 0% fairly reliably.  If you run the drain test and it shows you are getting normal battery life, then you may choose simply to live with the situation since it's basically a cosmetic problem at that point rather than a real functional one.

[Zvdo]

Hi,

I'm not sure it's good to charge it in full as it goes hotter and hot is not good for it. Is there an app with wich to read Mah that way I can read much more better % than than one shown on tablet.

[knottyrope]

all lithium batteries have built in heat sensors

reading in Mah is not a science with batteries but voltage is a more accurate way to sense depletion

I dont think there is an amp meter inside to do what you wish

[peter9477]

Knottyrope, I beg to differ! :-)

My app Battery Guru (link in signature) reads power, voltage, and current, and many other things.

While I don't bother actually displaying current on-screen, I do show power, as that's more useful.  Current changes as the battery voltage changes, whereas power stays roughly steady (for a given level of activity) so that's the one you see onscreen to help you understand what other apps are doing, and how well it's charging.

The current reading is logged, however, and is available in the CSV export file along with many other things including temperature.