reboot solved my problem (I hope)
I have a problem opposite to that of one of the other posters, who said he/she gets the charge lightning bolt but no charge. My phone charges, but does not show the lightning bolt or any progress in the charge bar, no matter how many times I unplug and replug.
However, the tipoff that my problem is software/OS related is that the charge bar did not indicate loss of charge either.
On rebooting, the charge bar appeared full (as it should have, since I had left the charge cord plugged in overnight, even with no lightning bolt) and when I plugged in after rebooting the charge cord to the phone the lightning bolt appeared.
Hope this provides a piece of the puzzle.
Battery causes charging problem
If I forget to charge my z10 overnight, in the morning it's completely dead and will not charge unless I hold the top button for about 10 seconds. THIS DOES NOT ALWAYS WORK and at one point I had to take my phone to the authorized center in Torrance. They said the battery is controlled by the software. They gave me a new battery and voila my phone started charging! Well that battery only lasted for 3 MONTHS and now it's dead and won't charge! Lucky I had a spare which I just put in my phone and it is now charging. So in short, the blackberry batteries really suck! You should keep a new spare.