rode my bike in and played again this afternoon

by the end of the set, i unplugged the fresh air machine and plugged that battery into the amp batttery, and the buck booster showed it was sustaining higher output wattages, up to almost 30watt. recently now have two 12.6 v lithium 15000mah batteries. thats good isn't it! otherwise turning the amp volume past halfway, the buck booster was quitting and turning itself off, two batteries showed it's about peak power output. i bought that battery for about $60 and now have to pay for it...cost money putting on a show. those batteries are now about $120