After 5-1/2 tanks of juice on the Cubis (3.5 ml each), almost 20 ml of juice, and just over two days of usage, I finally got it down to where the battery gauges are empty and flashing on me, telling me that I should recharge the batteries. However, the Cuboid is still firing fine. Once the vape finally started to feel a little weaker, I took the batteries out and put it in the charger. The voltage measured out at 3.15 volts. This mod definitely squeezes out every last bit of usable juice out of a battery.
Obviously if I was using it at 80 or 100 watts instead of 30 and 40 watts, the batteries wouldn't last as long, but this mod can definitely last an entire day of usage if this was your only mod and you're not cloud chasing with some insane super sub ohm build with low gauge wire.
I also tested out using the USB port to charge the batteries. They work, but I suspect that the charge rating is very low. I had it plugged in using my phone charger in the car and although I was pass though vaping at the time, I did not notice any increase in the battery gauge level
That's impressive! Thank you for the update. Battery life is a huge deal to me and it sounds like the Cubis is way up there in that respect. I also love that it takes the batteries down that far before the need to recharge. I am interested in finding out how long it takes to recharge the battery via USB. Not necessarily from completely dead, but from when it has about 1/4 charge left on it. I love to be able to vape and charge and I charge this way with my mods that allow it.