The power packs [Andy] looked at have a TP4221 controlling the charge cycle for up to four 18650 LiPo cells connected in parallel. The controller also boosts the voltage to 5 volts for one or two ...

Even doing this, you’re not realistically going to get more than a handful of hours operating voltage with an always active device. So why bother at all with supercaps, surely using a LiPo is so ...