You can also make batteries from cola or salt water.
High voltage battery.
Everybody knows how you can make a battery from a lemon.
If your car battery occupies a very high voltage above 12 9 volts it will reach dead status sooner than you expect.
The nominal voltage of normal voltage cells is at 3 6 3 7v while the nominal voltage of high voltage cells is at 3 8v or 3 85v.
The problem is these batteries have a low voltage.
High voltage cells lithium ion polymer lipo battery cells with normal voltages are fully charged at 4 2v while high voltage cells are at 4 35v.