I have been looking in to the topic inferred by my subject line of late as I work on a 1980 Suzuki motorcycle’s electrical system. I’m looking to use a LiFePo4 battery in place of the stock AGM to make the electrics neater.
My concern is battery overcharging and I’m looking in to how to implement this whilst maintaining the battery’s connection to accessory power (so as to not damage the alternator).
This is what I have come up with:
This circuit monitors a cell for being in the range of 2.5-3.5V. If above 3.5 the rec/reg output is disconnected from the battery via the FETs. The circuit on #FAULT is only in place to create a small load on the alternator. I think I will remove this as I understand it to be unnecessary.
The diodes allow rec/reg output to flow to the battery (and accessories) only when the cell voltage is ok, but disconnects the battery only from the rec/reg when charged to ~3.5V. The wire between REG_OUT and Accessory_Power currently exists in the loom.
The thinking is that a balancer would be connected and run at all times (or possibly just every so often) to maintain (somewhat) consistent cell voltage. This then means I only need one of the above circuits.
Hoping to get some feedback on this matter!
Update in resposne to Marko’s comment