05-17-2011 01:20 AM
Few days ago, I noticed that when the battery meter hit around 8% my playbook will shutdown automatically. I can't start it anymore and only can recharge it. I have the latest os and did the video chat agreement and fully discharge and recharge the device for several times.
i did security wipe but no use at all. I plug the power to let it boot up then remove the power. it shuts down at 7%. I plug the power again and remove. It shuts down at 6%. I repeated this for several times until the meter went to 3%. Then I gave it a full charge.
now the battery meter seems be calibrated a bit. It now shut down at 5% but still can't reach 0%.
I hope development team can fix this problem in the next update.
05-23-2011 12:53 PM
05-26-2011 12:00 AM - edited 05-26-2011 12:03 AM
The battery level indication in most of these devices is a prescaled reading. With Gell and Lithium type batteries it is difficult to have a very accurate reading as far as how long the battery will last until discharge. These batteries are very constant with their output until they reach a point where their output will avalanche. It is something sort of like having a pressurized oil supply feeding a hydraulic device. As soon as the oil runs out, there will be zero pressure.
The best you can do, is to run the device until it shuts down, and then recharge it fully. After about three cycles, you would have probably achieved the best possible for the prescaling.
In actual practice, if you were able to check the batteries with a volt meter, when the unit shuts down the batteries will probably read about 20% down from their nominal voltage depending on the range of leeway in the design of the system.
Normally with Gell, Lithium, and Lead Acid type batteries, they are considered too weak to be used when they reach 10% below their nominal voltage rating.
As for myself, when the power meter on the Playbook is showing less than 15%, I would be looking for a place to recharge it. my preference is to not let it run until it drops. I am not too critical with the accuracy of a prescaled battery indicator.
From what I can see, I noticed the Playbook will run for about 10 hours reliably providing I have only one or two applicaionis opened. Heavy usage such as watching HD videos would most likely run down the batteries faster.