I am building a device which is being powered by single cell Li ion battery (1100mAh), i am using MCP73831 Li ion battery charger and controller in my design to charge the battery.
I have got the schematics from this page : LINK
Note : R3 is 2K in my case.
I am having problem with B130LAW diode (D1), This diode is heating when the battery is kept on charge and it's extremely heating for the first few seconds when the battery is kept on charge from 0%
What could be the problem of heating of that diode.? OR anyone can provide me any other Load sharing circuit for my requirement
My load is around 200mA, i am also boosting battery voltage to 5V using LTC3426 chip, Keeping in mind MCP73831 is charging the battery at it's peak charge current 500mA.
Edited below :
I have just noticed that mcp73831, D1 and Q1 are all heating only for 5-8 seconds. Is this because of mcp73831 is in preconditioning state? It's only happening when the battery is totally down.
When I check current going to the battery from mcp73831 is about 750mA only for few seconds then it's coming to 500mA..
Testing Voltage across pin of Q1 and D1 (when the D1 is not heating):
I have disconnected battery to test voltage drops across diode and Mosfet, Vin to Diode is 5.06V and other end it is 4.88V.So voltage drop at diode is 0.2V, on the other hand voltage reading at mosfet pins are at Drain : 4.87V, Gate: 5.07V, Source : 4.33V
When connected to battery and charging voltages are as follows : Diode : Vin 5.00V and other end 4.74V voltage drop 0.26V MOSFET : Drain : 4.74V, Gate : 5.00, Source : 4.09
See voltages when all three are heating up, charging from 0% battery charge.