I recently upgraded a bunch of devices including phones and PC and ran into some very strange battery life and charging problems(Lesson #1 - change only one item at a time!). I wanted to share them here to help others that have faced similar issues
I was using the blackberry 9700 and found the battery life to be less than a day. I know I need to charge daily but 4-5 hours seemed really short. Well after a few days of running some experiments, I realized that my PC was set to go into standby in about an hour. When the PC goes into standby, the USB power was present but I guess the PC "brains" were shut down so charging also stopped. So while my BB was plugged in the battery charging supposedly overnight, it actually stopped after an hour. LESSON - Sometimes short battery life is more due to the charging source rather than the phones performance. Make sure that your source like the PC or wall adapter is "awake" when charging
Next issue was charging a completely dead battery. After a really long day, my BB battery went completely dead. I tried charging it from the PC but it just would not do it. Finally I was able to charge only after I plugged into the wall socket. Now here is what I found - turns out that sound you hear when you 1st plugin the device into the PC is not just for your entertainment
. When it does this, the BB actually tells the PC that it is there and ready to charge. But in order to do that the battery needs to have some life in it. Without this little juice, the PC cannot recognize that the BB is there and so it does not charge. LESSON - Have some charge left in the BB if you expect to charge from the PC USB port. If the battery is completely dead, you need to have your wall adapter in order to charge.
I hope that this information was helpful.....at the very least it will help people who have seen similar issues and may blame the phone. Some of the conclusions that I have reached were with the help of the the kind folks at RIM and with the help of a buddy of mine who designs circuits into the Blackberry phones...