How to build a home made supper battery charger for Li-ion battery

Three voltage level charge controller.

 Part list

Q1 = 1RF3205

U1 = BT156

R₁ = 220 Ohms

R₂ = 10K

R₃, R₄ = 1K

D₁, D₆ = LED

D₃ = POWER DIODE

D₂, D₄, D₅, Zener diode

 

WORKING

The thyristor automatically switched off the mosfet when the set voltage is reached.

When D₂ is connected it will be for 12volt battery.

D₄ is for 24volts battery

D₅ is for 48volts batteries.

The yellow led indicate when the battery is charging and switched off when it is fully charged.