Using FlashMe prolongs battery life (comparing with using PassMe)

I did an experiment today and found out that using FlashMe prolongs battery life (comparing with using PassMe). I did it by turning on a fully charge machine and let it ran a game until the NDS turned itself off. Here's the result:

11:16 am - 4:42 pm
(5 hours 26 minutes)

Comparing with 3 hours 50 minutes, I gained about 1.5 hours by not using PassMe.