for some reason my backpack just stopped today, charged up last night , green light comes on, fully charged up i thought, untill today. got back home and put charger in, went green , left in to see if charger will get warm as it normally does for an hour. still cold. i plugged charger in again ant backpack going great, lots of power. green lights on backpack itself showing all charged. unpluged and dead again. charger or battery. ? been looking around for another charger but all different adapters. anyone had a similar scenario.