I designed a battery charging, protection, and boost circuit for a project I am working on. However, I made a complete noob mistake and forgot to find the overcurrent value for the battery protection IC I am using, and it turns out the overcurrent value is too low.
The manufacturer makes multiple protection ICs in the same package size, so I can likely just swap it out with a new IC with a higher overcurrent value. However, overcurrent is specified as overcurrent voltage, and I am not sure how to convert this into an actual current draw.
I need the protection IC to allow charging current of at least 1A (no more than 2A), and a discharge current of at least ~1.5A (and no more than 2A). The battery is a 2200mAh li-po cell so this should be perfectly within spec.
This is the datasheet for the IC (I am using the AP9101CAK6-ANTRG1 variant): https://www.diodes.com/assets/Datasheets/AP9101C.pdf?src-supplier=Digi-Key
Here is what I have tried:
- I changed the value of R2 (from the example circuit, R5 in my circuits) to 1k from 2.7k . I noticed no difference in the allowed current draw.
- I shorted P- to Battery - to bypass the MOSFETS, this allowed for higher current draw, which confirmed that it is a problem with the protection IC and not the boost converter.
I also am having trouble with getting the battery to charge, I tried connecting the battery directly to the charge IC and charging worked normally, so again there is a problem with the protection circuit.
If it helps at all, I have attached my circuit schematics below
Any help would be greatly appreciated as I have struggled with this for several hours, but I think I lack the background knowledge to figure this out.