Dual output mains charger

[Jack T]

So with the current situation my camper isn’t coming out of the garage much which has made me think about maintaining the starter battery.

I already have a Victron 30a charger to charge my twin leisure battery setup but have been thinking about changing it for a triple output Victron instead. My thinking is one unit will keep both starter and leisure charged and be able to monitor them with Bluetooth. This would be useful at home but also when away actually using the van as normal. I have another use for my existing Victron so that won’t go to waste.

So my query is the connection, I already have 10mm cables to the starter battery from my DC30 B2B charger, these could be used for the purpose of reverse charging the main battery I would just need to add a connection back to my new Mains Victron charger. But if I were to do that would the B2B charger get confused and try to charge the leisure batteries thinking the engine/alternator is running?

The DC30 doesn’t use an ignition feed to run hence why I think it may cause an issue. Other option is to add a decent size relay on the battery side of the DC30 switched via an ignition live, stopping any connection to the starter battery when on hookup.

Long post, sorry! Anyone thinking about/done similar?

 

[Higgidav]

I charged my starter yesterday and noticed that my ablemail DCDC activated and started charging my leisure battery. I have monitors on both my starter and leisure so I watched what happened over several hours.

With the starter on charge both batteries showed charging status. Upon reaching float status I disconnected the starter and after a few minutes the ablemail shut down.

At this point the starter showed 98% charge and the leisure continued to show it was charging although the ablemail has shut down. This continued for a couple of hours until the starter had dropped to under 80% and then leisure stopped charging.

 

[Higgidav]

Here are a couple of screenshots.

The first is the starter batt which came off charge around 3pm.

The second is the leisure batt.

 

[Jack T]

@Higgidav yours is doing exactly as I thought it may thanks for the info.

I can’t imagine it would be good practice but in theory you just charge the starter battery from hook up and allow the B2B to do its job. Its no different to the alternator charging the starter. It would save me shelling out for a new charger! Other issue with that is not being able to monitor them individually on the Victron app which is handy.

It’s strange I didn’t think about it when I converted the van but would like to do something about it now.

 

[Pete C]

This is how my Ablemail behaves too. Start charging the starter battery and the Ablemail kicks in and charges the leisure battery. It shuts itself down in 5 to 10 minutes depending on the state of charge of the starter battery.

Pete