12V Inverter Battery Charger Circuit
This is a simple but old and not recommended inverter battery charger that can be used to recharge a 12V Battery
Keep in mind this circuit doesn’t have any protection like over charging protection, battery full automatic cut off etc so it must not be used on daily using circuits, it can damage your battery. there’s better chargers with protection circuitry available for low price in the market.
It is just simple and easy to build, use 10W(10watts) resistors for R1.
R1 and R2 is used to limit charging current, C1 is an electrolytic capacitor and is used to filter power.
For the power supply, use a 18V and minimum 2A(amperes) transformer. Don’t touch the resistors while charging as it can be very hot.
Depending on the battery amperage, It might take over 3 hours to fully recharge a 12V battery.