Hey, thanks for the tip on the Poweadd2 battery! I noticed a couple of you posted that you had issues with the Double Four cutting out when run on these batteries. Last year I bought the slightly bigger PowerAdd (32,000mAh), and it worked fine when I used the amp for practicing at home, but I just used it on a (loud) gig (where I had to crank up the volume) and the amp kept shutting off on me! Really annoying. It seems to be a safety feature on the battery, but I'm not sure if it's just the larger one, or if it happens w the smaller PowerAdd too. Anyone else have an issue with their Poweradd batteries on a gig where you really had to get a fair amount of volume? Thanks.