use while charging Li Ion batteries

http://talk.maemo.org/archive/index.php/t-6582.html
You can use it while charging. The battery doesn't have memory.

A lot of sources advise for LiIon batteries to let them go through a couple of complete charges/deep discharges the first time. It's claimed to help maximize the battery capacity.

 I've been careful to use my laptop off the charger almost every day (i.e. avoiding keeping it at 100% all the time, particularly when warm), and it's only in the third year that the capacity has started to drop a bit (I used to get 5 hours active hacking capacity, now it's more like 4 1/3). The old battery, on the other hand, completely died within a year after being kept 100% charged all the time. However, I try to avoid deep-discharging the laptop. In my experience that'll kill capacity quickly (I did it once with my phone and it's never been the same after that).


http://www.amazon.com/gp/help/customer/forums/kindleqna?ie=UTF8&cdForum=Fx1GLDPZMNR1X53&cdThread=Tx2SQC7FMI4IGB8

The reason you're warned not to use a device while it's charging is that the battery drain you're imposing with use may overcome the charge being supplied by the charger. If that's the case, the net effect is that your battery will continue to discharge. The reason some devices overheat in this case is that a faulty design (or faulty unit) tries to compensate for the drain by drawing more current from the charger. (Shouldn't cause the device to overheat but it sometimes happens.)

As far as the KF is concerned, the same logic applies. Using the device while charging will lengthen the time it takes to charge or if the charger is not supplying sufficient charge, you may find that it doesn't charge at all. But there are other reasons not to use the KF while charging, too.

First, the battery monitoring software in your KF may look like a "fuel gauge," but it's not. There is no way to accurately estimate the amount of charge remaining in a lithium ion battery. Instead, the estimate of remaining charge is based on the current available at any particular time. This current diminishes as the battery discharges and the "profile" of that reduced power is used to estimate the battery charge remaining.

If you charge the battery while using the device, the "profile" can get out whack, yielding an incorrect "profile" and in extreme cases making the KF believe it's fully charged when it isn't or vice versa. This is a bad thing and can lead to all sorts of unpredictable behavior including freezing, shutting down with battery charge remaining, etc.