To charge or not to charge (1 Viewer)

[Srp111]

Morning campers,

I have a cv40 which has 100w solar panel and a truma dual battery charger.

My leisure battery is an agm and is connected to the charger and works great.

I want to connect the second output to the engine battery which is a standard lead acid type.

Can I connect ? as the controller only let's you select one type of battery, agm, gel or liquid for both batteries.

Many thanks for your assistance.
Steve

 

[PhilMary]

I have one of those relatively cheap little boxes that bleeds charge from starter battery from the leisure battery, so no need for any extra wiring.
The starter battery sits about 0.4 volts below the leisure battery all the time except when the engine is running.

 

[David and Sally]

Go for a Battery Master. Sold by Van Bitz or from the shop on this site.
Dribbles charge from the leisure battery to the starter when there is about 0.4v difference. Much easier than using the solar controller.

The Vanbitz Battery Master

No More Flat Engine Batteries The Battery Master keeps your engine starter battery topped up by linking it to the leisure battery. This automatic one-way action passes a small trickle charge to the engine battery whenever its voltage becomes less...

www.motorhomefun.co.uk

 

[Srp111]

Thanks, but the controller is next to the engine battery so extremely easier to wire up and cheaper

 

[David and Sally]

AGM batteries are lead acid too but have a slightly different charging profile to flooded lead acid. Your controller can’t do two different profiles.
Does it really matter? Experts will be along soon to answer that. It may be that one setting will do both .

Found this.

Don’t combine Electrolyte batteries with AGM batteries​

It is not recommended to combine electrolyte batteries with AGM batteries for the following reasons:

1. While considering simultaneous charging of AGM and wet cell, the system will do one of two things:It will either keep charging the wet cell until it is fully charged or it may over-charge the AGM. Further, it may turn off when the AGM is fully charged while it would leave the wet cell battery only partially charged.
2. When a wet cell battery is undercharged, it would draw power from the AGM battery. This would lead to reduced lifetime of both batteries due to undercharging and draining.

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[Srp111]

AGM batteries are lead acid too but have a slightly different charging profile to flooded lead acid. Your controller can’t do two different profiles.
Does it really matter? Experts will be along soon to answer that. It may be that one setting will do both .

That's what I'm hoping, it's currently set to gel and not agm which is what the battery is.
Gel is the truma default setting

 

[David and Sally]

See above. Suggest gel is the wrong setting anyway.
Looks like set to AGM which will keep the AGM battery charged but not fully charge the wet cell. That might be ok for you.

 

[Srp111]

See above. Suggest gel is the wrong setting anyway.
Looks like set to AGM which will keep the AGM battery charged but not fully charge the wet cell. That might be ok for you.

That's great, thanks

 

[David and Sally]

That's great, thanks

Just wait for someone more experienced to confirm I would suggest.

 

[Itsmcb]

You will need to check your charger manual, but , most of the solar dual chargers only dribble 1amp to the starter battery and then only once the hab battery is fully charged so you won't actually get much charge to the starter battery at all.

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[Srp111]

Thanks

 

[the1andonly]

I currently have votronics duo chargers and had it confirmed by uk importers that the secondary charger for the sb is always lead acid irrelavent of settings for the lb. I realize this is not the same model. I also had a cheap duo version previously both trickle charges have been sufficient (except in winter)

 

[Srp111]

I currently have votronics duo chargers and had it confirmed by uk importers that the secondary charger for the sb is always lead acid irrelavent of settings for the lb. I realize this is not the same model. I also had a cheap duo version previously both trickle charges have been sufficient (except in winter)

Thanks I have set it as suggested above as agm and it seems to be working perfectly for both batteries

 

[poppycamper]

I currently have votronics duo chargers and had it confirmed by uk importers that the secondary charger for the sb is always lead acid irrelavent of settings for the lb. I realize this is not the same model. I also had a cheap duo version previously both trickle charges have been sufficient (except in winter)

You beat me to it... I was going to write the exact same.. I have Votronic Duo 250 with lithium hab battery's but also connected to lead starter battery..
Also confirmed with Votronic before connecting.