Recent content by mark963

Isn't Q1 (the S9012) a PNP transistor, not an NPN?

It seems like a lot of these types of boosters are adding the Ah capacity of all of the cells in them, even though they are in series. This could be as low as 4S, but 5S or 6S would give a little extra voltage to dump current into the starter batter for a quick charge. If is a 4S, then 12000/4...

I've had used A123's running 4s on a 12V UPS for many years and those work OK. I think they're near 10 years old and the elevated temperature (35C/95F with no load) in the UPS has finally worn them down. Lipos really don't like sitting around at full charge and they'll age fast that way. A...