Battery problem

[Scooter911]

Hello. I've been following this forum for quite a while now as a guest, but I have a question that I could not find an answer for when I searched so here goes:

I have a 2003 H2. My 2 year old daughter loves to play in the truck and watch movies on her DVD player! Cheap babysitter!

Anyways, after she watches movies for around an hour the battery is dead and I need a boost to start.

I took the truck to a garage and the mechanic connected a battery tester to the battery and it checked out good (however, I always thought you had to remove the battery and the entire test took hours not minutes).

He also checked the alternator with the same tool and it read a charging voltage of just over 14 volts.

So my question is... is it possible the battery is dead or dying even though the battery tester gave it a thumbs up? Surely 60 minutes of watching movies can't be enough to kill a truck battery!

Once I get a boost the battery gets charged and I'm good to go - unless of course I allow my daughter to once again watch movies with the engine off.

Can anyone shed some light on this? I'm strongly thinking about going to the GM dealer on Tuesday and buy a new battery. I tried to price one at Canadian Tire (Yes, I'm Canadian and live in Kingston Ontario) - but they didn't have anything even close that would fit.

Thanks.

Scooter 911