DIY Powerful 12v battery charger circuit with Auto cut off

I will show you how to make 12 volt automatic cut off battery charger that can be used to charge inverter batteries as well as car batteries there are already lots of circuits like this with only bridge rectifier that will not protect your battery from over charging also there are these type of auto cut-off circuits which lacks the constant output voltage and cannot cut off at precise set voltage so i designed the perfect circuit with adjustable constant output with 10 amperes and precise cut off voltage as you can see initial circuit is based on bridge rectifier with filter capacitors for current smoothing here lm317 is used to adjust output voltage and mj2955 pnp transistor is used to bypass up to 10 ampere's current to output since lm317 can give only one ampere output here the voltage divider circuit is used to set cutoff voltage so that when battery reaches to threshold it will trigger the transistor relay coil will turn on and charging to battery will cut off and will indicate battery is fully charged hence prevent battery from over charging for easy assembly of this circuit i designed t now let's solder all the components to pcb our soldering is complete and it is time to trim the excess leads of all components you can clean the flux residue using isopropyl alcohol now our circuit looks nice and clean and is almost ready to test use heatsink thermal paste for effective transfer of heat to heat sink can use up to 10 amperes 12 or 12 step down transformer connect transformer to input terminal connector to calibrate the circuit connect multimeter at output use screwdriver and adjust first potentiometer to set output voltage at 14 volts now adjust another potentiometer to set cutoff voltage rotate slowly to clockwise till green led turns on this button can be used to restart charging if circuit is in cut off position i will charge this car battery to test the circuit now charging to battery is cut off as battery is fully charged.