Hey guys,
I have a stereo boombox that I’ve had for years. It’s a pretty rugged design, so I recently had the thought of making a few upgrades to it to make it more useful when I go out in the boat, car camping or just working in the yard. One of the first things that I would like to tackle is how it’s powered. It has a 12VDC jack for use of the AC adapter. Also, it has a place for 8 D-cell batteries. What I would like to do would be to replace the D-cell batteries with a couple of high capacity lithium polymer batteries. I have room in the battery compartment to put 1-2 packs as well as some hollow areas within the case where I might be able to get another pack in there. I don’t want to use an external li-poly charger, so I was thinking about making my own custom charger. My biggest problem is that I can’t find a lot of useful design information on how to manage charging multi-cell batteries. Since it’s a 12V system, I’ll probably be using 4S batteries. I’ve found some charging ICs, but most seem to be just for a single cell. Has anyone worked with li-poly chargers before that could point me to an example circuit?
Thanks.