diy solar

diy solar

NDS solar controller leisure battery back feeding into starter battery

brackstone

New Member
Joined
Mar 27, 2021
Messages
109
Hi all.
I have been talking to a few people on a Facebook group about the NDS SC300M solar controller. This controller is a MPPT device which charges the leisure and starter battery from solar panels

They have found when the sun goes down there is a current draw from the leisure battery with all the van switch off. If they pull the fuse from the NDS control unit the current draw goes to zero. So seems the leisure battery is reverse charging back into the starter battery (balancing both batteries).

If they operate the central locking on the van there is a small current draw from the leisure battery 2A for a few seconds which drops back of to zero.

So my question is are these solar controllers designed to balance the starter battery with leisure battery when solar has gone off(no sun).

If so when starting the engine will there not be current draw from the leisure battery.

Will it actually be feeding from the starter battery to van system and potentially draining the starter battery
 
Seems like there should be diodes in the Charger so both batteries can charge from solar but no current can flow out to other devices. If its still under warranty perhaps they will replace it. Alternatively a possible DIY fix would be to install a diode(s) on the Leisure Batt+ so current cannot flow backwards when the sun goes down.
 
Seems like there should be diodes in the Charger so both batteries can charge from solar but no current can flow out to other devices. If its still under warranty perhaps they will replace it. Alternatively a possible DIY fix would be to install a diode(s) on the Leisure Batt+ so current cannot flow backwards when the sun goes down.
These are new Adria vans and we are seeing this on more than one van on the group. Even had fuses blown for no reason which I now think is when the engine is started as this nds controller will be bypassing the charge relay.
I was wondering if this saw some strange new feature on dual battery solar chargers. Nothing in the manual so now I think this is a fault on the units
 
If its happening on more than one unit then it is most likely is some kind of design or manufacturing issue as you said. Shottky rectifier diodes are cheap and easy to find.
 
Back
Top