http://www.cnet.com/products/hp-compaq-presario-cq62/ pegs this at 4 years old. That's well beyond the expected battery life. The battery was rated at 300 cycles so if the battery is failing, that's what I replace. There are a lot of folk that want to be sure it's the battery but so far the cost of testing a battery is more than the battery so we slip in a new battery and see if that clears it up.

http://www.hp.com/ctg/Manual/c02641795.pdf does seem to tell what the LED signals do.
Bob