Hello. I have been able to communicate with the device over I2C with no problems. I can write and read registers. I am trying to configure the device manually, but so far it does not behave as I expect.
For the power source I am running into the VIN with a 12V 2A DC power supply. On the VBAT I have connected a 7.4V 5200mAh battery with maxim integrated fuel gauge(has coulomb counter, ammeter, voltmeter) attached. On the VSYS pin I have a load resistor.
By writing registers I have configured the max charge voltage as 8.4V(this is the nominal charge voltage according to the battery spec sheet). I have set VSYS with a min of 7.4V. Both of those values are fine. I can verify them with a multi-meter. When I unplug the power supply, the battery does discharge over the VSYS load providing power. When I plug the power supply back in, the VSYS goes back to the min system voltage that I configured. This behavior appears normal to me.
The problem that I have is with the charge current. I am trying to write the charge current register with 0x0400 to give 1 Amp of charge current. However, no matter what I try, the charge current never changes. It always reads back from the device as either 0x0080(128mA) or 0x0000.
So it is either trickle charging or not at all. I know there are some operating modes and conditions which cause the device to write 0 or 128mA to the charge current register. I am not sure how to force it into fast charging mode with 1A of charge current. Do I have a configuration problem or some other mis-understanding about how this works? Does the battery have to be dis-charged a lot before quick charge happens??
Here are my configuration registers:
Charge Option 0: 0x020E
Charge Option 1: 0x9210
Charge option 2: 0x0237
Charge option 3: 0x0020
Status register readings:
prochot status: 0xA880
charger status: 0x8000
Although I have a 12V power supply plugged in, the input voltage register only reads 7.7 volts. Is that a problem? What I desire is to power the system with 12V 2A. The internal buck converter should bring that down to 8.4 volts or less at 1A to charge the battery, and 7.4 Volts to the VSYS to power the rest of the system. When the power supply is unplugged, then the VSYS should be provided by the battery.
Do I have some problems in my configuration? Any ideas?