I'm evaluating the LTC4162-L for a solar charging application. I have a DC2038A-J demo board to run tests. when I tried to verify the 54-100uA battery drain current when the input solar panel is dark, I measured 15mA out of the battery. There has got to be something else running on the board, but I'm not sure what. How can I verify the 54-100uA of current drain from the battery with a dark solar panel on the DC2038A-J?
Thanks so much!
I'm not sure why that would be. If you remove the solar panel entirely, do you still see this high drain current?
Where is this 15mA going?
Thanks for your quick response! I just checked, and having no solar panel plugged in results in the same outcome as having a dark solar panel plugged in. I also verified that my solar panel and test setup was working by putting the panel in the sun to be sure a charge current was delivered.
I'm not sure where the power was going -- I'm using your stock DC2038A-J so I was hoping Analog would have someone familiar enough with the design to say if that was reasonable or not, and if I could make any modifications to measure the battery drain caused by the LTC4162. Would you know someone that I could ask at Analog?
DYoung said:I was hoping Analog would have someone familiar enough with the design to say if that was reasonable or not
That's me actually. There's no reason this should be happening. If there's no load on VOUT, I can only assume something in the circuit is damaged and causing this leakage.
Leakage current from the battery goes into the BAT pin, but this should be in the uA range.
Does the circuit seem to work normally aside from that? Sometimes there can be damage as a result of connecting high-capacity batteries with high inrush capability, though the board does have some protection against that.
Yup! Everything seems to work fine with a solar input. Would you have a demo board that you could recreate the test on?
Is there anything to test beyond connecting the battery and measuring the current from the battery with no VIN and nothing connected to VOUT?
This is a common use case which I have tested in the past. With VOUT unloaded, there is no reason there should be 15mA of drain on the battery under any condition.
Do you have a procedure to test?