So I've soldered a PCB with the BQ25504 Harvester while following the recommended layout and schematics on the datasheet for a Solar Cell. I set the battery operating range to be from around 3V to 4.2V using the ROK Resistors (please see figure below).
Yet, using this set up (see figure below), when I plugged in the Flex Solar Cell and the Battery, the maximum it charged to was around 3.86V. (Please see figures attached below of our schematic, PCB, and Set up)
Since this didn't work I ran a test:
I attached a current source at the Solar Cell, and a Voltage Source at the Battery Plug in order to test the varying current according to the battery's charge voltage. (See figure)
I ran two tests:
1) When I lowered the Battery's Simulated Voltage to around 3.0V, I saw that the current supplied also got lowered to almost 0 (which I assumed was what is supposed to happen).
2) This test was the issue: When I slowly increased the voltage from 3.3V, I saw the current reducing. This time though, it cut off at 3.92V instead of 4.2V.
What am I doing wrong? What could be the problem? Kindly check out the schematics and configurations and let me know. I know that this board was replicated and soldered by 2 other people, and they ran into the same problem.
