We design a 24V charging System using BQ24630, ACSET and ISET1 is adjustable through MCU. Battery is 19.2V LiFePO4.
When the system powered by 24V AC to DC, 2.5A power adapter, everything works perfectly. It can charge the system based on ACSET and ISET1 values.
We also want to charge the system using a pneumatic generator as a backup power source when AC adapter is not available.
We use this one. It provides 24V with max 500 mA at 7 bar input air supply. Two pneumatic generators can provides 1000mA, we tested these setup using a load tester, it works fine. It can output 1000mA as advertised.
In our charging circuit, We use a 100uF capacitor at the input of the pneumatic generator to stabilize the voltage.
We tested using two pneumatic generators, system load 300mA, BQ24630 can pick up the power source and charge the battery at around 600mA rate.
However, when the system load increases to 600mA, BQ24630 cannot pick up the power source, and PG pin is blinking.
I tried to use a higher capacitor like 470uF or 1000uF, not seems to work.
I attach the schematic, waveform of PG pin and power supply of pneumatic generators. C1 to C3 are power supply capacitors.
Could you suggest a voltage stabilizing circuit that can smooth out the voltage and let BQ24630 to pick up the power source easily?
What's the requirement of Power supply?
Wave form: Yellow is pneumatic power source, light blue is PG pin. Normal operating, this is when system load is low, less than 300mA. Charging ok.
PG pin Blinking, cannot charge. this is when system load is 600mA,