So I’ve been having issues with my AGM starter battery on my campervan running flat, as everytime i open a door all the electrics boot up and if im parked up for a while and not moving its enough to give me problems.
I rather think that the starter battery is goosed, but going to at least give it a go at desulfating and seeing if i have any success before looking at replacing.
In the meantime, I’ve wired up the 4a trickle charger from my multiplus to the input side of my Orion XS so the starter battery is on a constant trickle. However due to the leisure battery being lithium and the starter battery being AGM i think the difference in voltages will mean the starter battery is at risk of constantly being overcharged. Has anyone looked at utilising one of the internal relays on the Cerbo GX to open and close the trickle charger circuit at certain voltages?
I would not be worried too much about keeping the trickle charger on permanently from the AGM perspective as it will see around 13.2V which is a storage charge voltage. The issue is making sure the trickle charge is stopped on low lithium voltage which depends on your battery/BMS. Putting it through the Cerbo relay is certainly an option, or a programmable relay on the Multiplus.
Nice write up, its a real shame that this trickle charger isnt a true charger. I guess the easiest option is to just put a switch in the circuit and if i notice the starter battery voltage starting to drop when parked up for some time, just flick it on for a few hours.
I think leaving it on permenantly will just cause issues with the engine shutdown detection on my Orion, and as the van is now fully converted running an additional D+ signal wire will be a massive pain