ESP Ultra Small 5V Micro USB DIY Powerbank Charging Module Circuit Board Step Up with LED Indicator Micro Controller Board Electronic Hobby Kit

Features: 1. Charging and discharging indication, based on advanced HT4928S IC 2. Internally installed charging and discharging power MOS 3. Preset 4. 2V charging voltage, precision ±1% 4. Max 8uA standby current 5. Intelligent charging management and discharging management 6. Intelligent temperature control and over-temperature protection 7. Intelligent output over-voltage protection, short circuit protection, overload protection 8. Intelligent overcharging and over-discharging protection 9. Support trickle mode and zero voltage charging 10. Auto on /off with load detection Light display: Charging: When charging, the indicator LED red and blue flash alternately (blue light continuous on means fully charged) Discharge: Blue light on and starts flashing when battery voltage drops below 3. 2V (low battery) and it shuts down automatically when battery voltage reaches 2. 95V.