I'm using my Big Brother 3.7v full time now that I have some 3Ω E2's to run on it. Two 14500's last a really, REALLY long time.![]()
I'm using mine with high drain batts and LR510 atties. It's very nice. It's a ridiculously small mod to have the battery life it has. And as an added bonus, it works just fine with one battery, too. For short trips where you know one 14500 will last you just fine, you can put a 3ml juice bottle inside the box where the second battery goes.
Ken makes solid mods. I couldn't be happier with mine.