I have a Gardiner backpack that came with a standard wall charger.
I wonder if it can be charged directly from the cigarette lighter outlet. The output on the power brick says DC 12V which same as the car socket. Perhaps if I put a solar panel charge controller between the socket and backpack it would protect it from overcharging the battery.
I don't use the backpack a lot these days so would prefer to charge it on the way to a customer just like an auxiliary battery from split charge relay. Has anybody tried something similar?