Originally posted by Peter777 So I bought second hand but unfortunately it is having poor battery issue.
It eventually lasts no more than 2 hours. That could be ok but weird thing is that even if full battery is inserted, then left inside without even using it at all, it is completely drained overnight. Meaning like it's consuming power somehow even when powered off.
I have suggestions but no experience with this exact battery and camera:
a) Did the camera and battery always have this poor battery life? If not, did anything change?
b) Do you have a volt or multimeter? If you don't leave the battery in the camera overnight, does it still carry a charge outside of the camera?
Batteries these days are 'smart' and have chips in them that can be defective even if it's new.
c) Where are you storing the camera overnight? Is it near any EMF sources?
Mark is probably right that it's the camera and if your firmware is all updated, it's mostly likely internal parasitic drain or a short in the camera.