Lithium battery charging and discharging boost module V1 has been verified to contain 9V battery shell file

Usage: DIY multimeter rechargeable battery, various toys, etc. Verified

Maximum 1A programmable linear charging current
for single-cell 3.7V lithium battery, full 4.2V
constant current/constant voltage charging, with over-temperature protection
soft start to limit surge current, with battery reverse connection protection
low power standby to extend battery life Use time,
charging status dual output, no battery and fault status display
can be activated at 0V, 2.9V trickle charging,
operating temperature -40~80 C,
input voltage range 4.2V~6.5V,
output voltage 4.2V-28V adjustable,
maximum power 5W

Modifying R2 can change the charging current

Charging current (mA)
50
250
580
1000
Charging indicator light description
The module can roughly judge the working status through the status of two LEDs. CHRG
is a red light and STDBY is a blue light. When the battery is charging, the red light is bright, the blue light
is not bright, when the battery is fully charged, the blue light is bright, and the red light is dimly bright. If there is a boost output, it will vary
depending on the output power. It is possible that the red light will always be highlighted when charging
. When there is no load or connection, the blue light will be on and the red light will be dimly lit.