Keeping 'van starter' battery topped up ?

[thebarber]

https://sterling-power.com/products/bat ... maintainer
Am I right in thinking I can attach this to my leisure batteries and trickle charge my van battery and would it be safe to do so?
I've read that eu6 smart alternators only charge the battery to 80%, is there a reason for this?

My setup is Abso dmt1250 dc-dc charger connecting van to 2x130ah leisure batteries, also topped up with 270w solar.
Cheers

[richbee]

Don't know about the Sterling one, but I've got the CTEK model which does exactly that - trickle charges the main battery once the leisure battery is full from the solar panel. Works a treat.
As far as I know, the only reason the smart alternators charge to only 80% is to save energy during charging and therefore save CO2, there is nothing about the batteries which means you can't charge them fully.

[richbee]

Sorry, please disregard my last post - I just clicked on the link and realised it is a different type of product - doh!
Mine is a B2B charger which also trickle charges the main battery

[johnporter11]

I've been reading the specs for your Abso dmt1250 and surprised that it doesn't list reverting to trickle charging your starter battery by solar when your leisure batteries are full. My Renogy B2B does. I believe the CTEK and Sterling do also.

[thebarber]

I don't have it wired to the ignition to enable 'soft start' so that might help but I'd still like a trickle back to the van battery.
So am I right thinking this is the right tool for the job then?

[stfvrg]

I fitted a Lead-acid Solar Battery Charge Controller that monitors the starter battery voltage and allows charging from an external charger when voltage drops under the set low value and stops once it reaches the set high value. I then added a small DC/DC to transform my 28v LiFePO4 leisure battery to fixed 13.8v, but you can fit any charger you want.

https://a.aliexpress.com/_u7ncgD

https://a.aliexpress.com/_vkjoEl

[Blizz]

There are MPPT controllers that have that option, for instance the nice Epever Duoracers that can be bought in AliExpress.

Also you can change the battery charge target with Forscan, by default is set to 80% but can be incrased too.

Cheers,

David