I’m currently charging a single Li-ion cell from a dedicated charger IC. Due to the intermittent nature of the charging source and Li-ion not being able to charge below 5 deg C it is possible that the battery may run below it’s ideal level. I am adding a supercapacitor so that the circuit can operate in low power mode if the battery is in deep discharge.
I’m struggling to work out a simple circuit that could charge the supercapacitor from the same charger IC, whilst trickle charging the battery, provided it’s above 5 degrees C. I have a dedicated microcontroller for the charging circuitry, so I can digitally measure and control various parts. I also have a 3.3V reference source that can be used.
I’d prefer not to introduce a completely seperate switching converter to charge the supercap however I’m aware that this could be a solution.
Interested to hear any suggestions on how best to tackle this problem!