As I know, If you completely discharge a lithium-ion battery, it is ruined. To prolong the batteries lifespan, you want to charge the battery before it gets below a 20% charge or just charge it as often as possible.    Quote:  

Yeah man, I think most lithium-ion batteries are like that if you deep discharge and charge them. Maybe you should try to charge the battery more often instead.

  I'm using these settings with TF10 and find it sounds comfortable and enjoyable for most of my music, like pop, rock, and instruments. 80Hz: 0 (any boost here sounds kinda warm for my taste, I just let the Mach3bass to do all the bsss boost) 220Hz : -1 wide (less boxy) 1.4kHz : 0...

HI everyone my first post here.  Just want to say I built my O2 with total cost of $50 (include case, battery and adapter ) and 6 hours of my Sunday afternoon( lots of questions asked). And this is my first time ever building an amp or soldering any PCB. so I'm sure any experienced DIYer can...