How To Make A Solar Powered Laptop Power Bank

 

Supper Li-ion battery charger circuit diagram 

 

Materials

1. R1=220ohms, R2,3=10k, R4=1K
2. D1,D6=led, D2=24V  zener diode,  D3=in5408
3. Q1=IRF3205, U1=BT151.

The switch sw1 should be replaced with a push button type .

To avoid overcharge the 24v zener diode should be connected to the battery positive terminal. This will automatically switch off the charging current as soon as the voltage reaches 26v .

Voltage  Regulator.

 

The voltage regulator will supply the required voltage to the laptop when RV1 is preset to produce 19v as open circuit voltage before connecting to the laptop.

24 Volts battery bank.

Connect 6 Li-ion batteries in series to form a 24v-26v  battery  bank, the number of  batteries in parallel will determine the durability of system at least 4 batteries should be in parallel.

This system eliminates conversion wastages encountered during DC-AC-DC conversion process.