I have created a circuit as a hobby project for my router. With this Project I want to power my two 9V routers in case of a Power Failure.
Two routers combine uses around 600mA.
I’m using two 18650 batteries in series as backup power and 2A 9V SMPS power supply to power two routers.
Also I’m using Atmega328P chip to monitor battery voltage and ACS712 Current Sensor to keep track battery capacity.
Problem I’m having with this circuit is that when power goes out MOSFET getting very hot and routers getting reboot. After few seconds routers get power and works normally.
Also if I pull the wall power supply from circuit to stage a power failure, circuit switches to battery instantly and MOSFET doesn’t get hot.
MOSFET I’m using in this circuit is IRF9530.
MOSFET getting hot and not switching to battery instantly because when a power failure happen power adapter doesn’t go to 0V instantly?
Any help to identify and solve this problem appreciated.