My Google-foo just doesn’t seem to be working tonight. Does anyone have any clue if the capacity meter on those USB voltage/current/capacity testers are realistically accurate?
Considering the error in measurement of voltage and current can I trust this number to any extent?
Check HKJ’s reviews.
I did read hjk’s review of a usb tester prior to posting. His review doesn’t cover accuracy of the capacity reading. He does cover voltage and current, but there was nothing to confirm accuracy of the capacity reading.
Capacity is current multiplied with time and time is very easy to get fairly accurate, i.e. any software without bugs will have about same precision on capacity that it has on current.
But when measuring consumption for usb devices it will probably have more error, due to the voltage drop in the usb meter.
Ultimately you end up measuring stuff with the same “stick/reference”. Accuracy is not dead on, you need much more expensive equipment to do that. But you can get a general idea of what things are doing and compare similar stuff. Like I found out that my USB cables came in an amazing range of quality and throughput. I ended up throwing out a lot of useless wires.
Or discharge, then charge, with a charger that tells you how much the cell took.
That’s what I’m looking to do is sort out the good power banks from the bad / counterfeit. Trying to find a way to do that with what I have, which is a usb tester and a multimeter
Can you remove the cells and check them individually?
I’m not so much worried about cell capacity as the final capacity after the voltage boost.