While I never had any problem with the P100 battery life, the P500 quickly became an entire different matter. Just a session of photos and videos was enough to drain its battery - leading me to believe there was something wrong with the battery or camera. This was made words as I found that, even if I left the Nikon P500 unplugged after fully recharging it... after a single day the camera would be dead!
Update: Nikon has finally released a firmware update that fixes this issue.
I searched for answers on the internet and found lots of other users complaining of similar problems; but surprisingly, Nikon's official statement was there was nothing wrong with the camera - that it was user's fault!
Then I came across a thread where a user suggested turning off the "Charge by Computer" option which is in "Auto" by default, and to my surprise... it did fix the P500 battery problem!
I can now leave my camera unplugged, knowing that will still have a nearly full charge the next time I need it.
This is something Nikon should really acknowledge and take a serious look into, as it is clearly a firmware problem! Blaming the users really doesn't suit a brand with such a long standing tradition in providing us with high quality cameras. I really find it hard to believe how they could have launched a camera with such an obvious bug that is affecting hundreds or thousands of people.
Anyway, turn off the USB charging option, and you should find your Nikon P500 becomes the camera it should be.
