Folks, Do battery charge controllers usually disconnect the input from the battery, when the external supply voltage is not present? Is there a potential leakage path back through the unit that provided the charge voltage?
In particular, I'm looking at MCP73832. There is a blurb about it in the datasheet (section 5.1.1), and there is a MOSFET in the block diagram (p.2) that could do the disconnection. Still, I’d like to ask what your thoughts and experience is, folks.
@NickAlexeev from what I've seen on battery charger ICs (specifically the lithium ion ones I've been investigating in the last 6 months) they have blocking diodes/FETs to stop backwards flow, but no idea on what magnitude of leakage there could be
@NickAlexeev in my experience for the good ones there are just a few µA leakage, for the bad ones it can have a path through a few kΩ and discharges the battery. I recently had a case where an IC failed, causing such a thing (plus overcharge beforehand) which destroyed one of my battery packs :/
