STM32 as Lipo polymer battery charger controller

[ashutamar]

I have attached the schematic actually trying to replace the mcp73831 so may

I program stm32 to connect or disconnect using MOSFET to charge or control my lipo battery if its rating its 0.7C, or you can say approx we need to charge 500mah with or less 500mA charging rate .

Btw This lipo battery for emergency/backup battery its not going to use in long it will used once in a month my main doubt is about charging the battery using smt32 control pin will be the voltage analog r battery volt reading pin

[LCE]

Hmm, I don't understand what kind of trick you're pulling with that MOSFET circuit, at first glance that looks completely wrong.

And also the MCP73831 circuit with the MOSFET body diode and the diode D5 looks fishy.

Be careful with Li-batteries!

[Richard Li]

You notice 0.7C charge rate for your battery is 500mA, so your battery is ~ 700mAH, this is small battery, even 16650 normally >1500mAH.

You try driver PMOS turn on this is totally wrong as LCE noticed, PMOS turn on need Vgs <-0.5V.

[Richard Li]

I guess you want disconnect the power source after fully charge, there are two ways:

1. If you use 0.7C charge, after 1.5 hours, it will fully charged, you can count the timer, disconnect.

2. You can use one ADC read back battery voltage, after >4.2V, disconnect.