generally, that I only use for demonstration, the power is turned off by the switch.. and I only turn it on when I want to show how it works. and generally I use one cell or battery from the phone.. but that now I want to use only Li-poly batteries and 13350 cells from e-cigarettes because that's all that will fit in a 1:24 scale model. However, when it comes to charging batteries, e.g. 13350, I use a TP4056 charger, but one guy recommended replacing the SMD resistor that is on the charger. because charging with this charger can damage the battery.. but there is more in this tutorial (so as not to write too much)
https://www.youtube.com/watch?v=qCFdlcmdSMs&t=923s