3.7 volts is strong enough for me. I'm impressed and really happy with the eroll in that respect. In fact, I've been looking at the ego c from Ovale as, at least the 650mah, says its 3.7 volts and joye doesn't make one. Their's is 3.3 regulated. If you go unregulated, you can get 3.7 for a while. I like passthroughs though so guess I'll contact them to find out the volts. I see no point in buying a VV when I only want 3.7 tops.