At some point, the 3.6 V of a single lithium ion battery just won’t do, and you’ll absolutely want to stack LiIon cells in series. When you need high power, you’ve either got to increase voltage or ...

Here’s another hack that we would definitely discourage you from trying at home, 244 9 volt batteries wired in series. There’s really not much more to it than that, but [jersagfast] takes this setup ...