Thanks Spruce. I’ll re-read through later & try to take it all in.
Yes I can turn it off manually by a switch on the dash but you have to do it every trip.
I know I’m alone but I actually don’t mind stop/start.
New battery was a £150 stop/start battery by the way.
Thing is I’m pretty sure my leisure battery is charging as the voltage says 14.5 on the controllers with engine running & Sterling is lit up. It’s just my starter battery isn’t fully charged I’m guessing as the stop/start would kick in as it does when I’ve bench charged the starter battery.
At 14.5 volts it is charging.
The last split charge relay I had on my old van was a voltage sensing relay. The relay worked within preset parameters. So often when I switched the engine off the relay stayed connected for a time afterward. With the leisure battery at a lower charge than the starter battery meant that the leisure battery was drawing power from the starter battery unit it dropped to below a certain preset voltage.
The Sterling unit does the same. It continues to draw current from the starter battery until the voltage drops low enough to trigger the Sterling unit to switch off. I wouldn't know if this feature was causing starter battery drain or if you have a failed battery. (There was discussion on the forums that the early batteries fitted to stop start vehicles and those with reg braking were suffering premature battery failure.) This feature may also be causing the lower voltage readings on my starter battery.
There is an option on the Sterling unit that gives the option to connect the unit's control to the ignition switch. The moment the ignition switch was switched off the Sterling unit powers down. The disadvantage is that if you have to switch your ignition on to listen to the radio you are triggering the unit to switch on and connect both batteries together, not seen as an ideal situation.
With the old split charge relay we also had the option the connect the trigger to the alternator charge light circuit. I would see this as a better option but if I chose this route would confirm with Sterling that I could do this and not damage the B2B charger.