Bioenno Power BPP-120

Might buy that someday. Get ready for the end of the world. Except, I'll need a bigger one. Or just buy more then one.

I probably won't live long enough to need it, I'll be dead before the nukes land.

Don't buy on Amazon, only a one year warranty, from a third party seller. Buy it directly from them.

720 W-hr Power Pack (BPP-M720) that should do the trick, but it's almost 1k.

I can charge my bike with that, while riding it of course. Not the 720 W-hr one, that would be heavy probably. But the cheap one. Might be a bad idea to use the battery and charge at the same time.