Charge Indicator

This experiment helps me work out the design of a charge status circuit I will add to my existing project board that uses a 1s LiPo power source protected by a DW01 based BMS. The source attached to the voltmeter simulates a charging LiPo battery 3v. to 4.2v The MOSFET hooked to the pulsed source acts as a synchronized switch that simulates the protection chip (DW01) allowing charge from a 5v source (USB) until the battery reaches 4.2v whereby Over Charge protection occurs cutting off the ground path and terminating the charge. The red LED is meant to indicate a charging source is connected. The green LEDs begin to glow as the battery charge approaches 4.2v when the MOSFET toggling causes the green LEDs to turn full-on, indicating full charge. A problem is that when the 5v source is removed and the MOSFET switch is closed, the indicator LEDs still operate. This signifies DW01 allowing discharge to load. I need to add functionality so LEDs only operate when charging source is present.

published 5 years ago