Leisure battery charging arrangement

[Doug24]

My son has a 2015 Ford Transit H3L3 which he has started converting to a camper van. We are learning as we go!

The van has two batteries under the drivers seat and a 240V three pin socket, which doesn't appear to work, underneath the handbrake. There is a single 60A customer connection point to the side of the drivers seat.

He has bought a 180Ah Varta leisure battery but is unsure how best to connect this so that it is charged from the alternator when the engine is running.

Opinions seem to vary. Some say use an automatic charge relay in the positive line, connecting to the existing service battery. Others the same but connecting to the starter battery. I'm favouring using a B2B (battery to battery) charge controller, such as this Votronic device (https://www.12voltplanet.co.uk/votronic ... 12-30.html). But can this be connected to the customer connection point, or must it be connected to the starter battery?

He may want to add a solar panel at some point in the future if this affects the best approach to take now.

Any advice gratefully received.

[hectors-tranny]

A B2B charger is a fantastic choice, although pricey. Wouldn't be without mine. They are so efficient at charging your battery you may find you don't need solar at all (unless you are sitting long periods without running the engine). Plus your leisure battery will last longer.

I bought on of these: https://www.12voltplanet.co.uk/sterling ... v-30a.html

Easy to connect up. My van doesn't have an aux battery, so my only option was to connect to starter battery. I doubt you'd go wrong doing that. (I don't know aboout Transit aux batteries, but if there's some sort of relay breaking the connection between starter and aux batteries, this might hamper the B2B operation.)

So it's just a case of connecting starter +ve to B2B (fused as close to starter terminal as possible), same for leisure battery +ve, then one decent earth to the B2B.

[Backbone of Britain]

You need a b2b charger, you can’t use a vsr as you have a smart alternator. Connect the b2b to the front battery (aux) with a fuse as close as possible and a fuse at the other end by your leisure battery.
I have the sterling installed in my camper https://www.12voltplanet.co.uk/sterling ... v-30a.html
Oh and follow the instructions for setting up for vehicles with a smart alternator.

[bortaf]

As said B 2 B is the best option and will charge the leasure battery quicker, i used the renogy DCC50S https://uk.renogy.com/dcc50s-12v-50a-dc ... with-mppt/ as that will also handle solar at a later date, a nice all in one solutuion, although more expensive than the sterling option but then it also handles solar, it's also configurable for differant batery chemistry and it will charge the vehical battery when the leasure battery is full form solar, handy if your parked up for a while as the front battery tends to get hit with the constant load from the BCM alarm,C/L ect

[Doug24]

Thanks everyone for the replies.

Looks like a B2B charger is the way to go.

Could the Sterling charger be connected to the 60A Customer Connection Point (CCP), as it should only draw a maximum of 30A? I have seen other blogs where they have done this. Any downsides? Access to the connection point would be easier that the front battery.

Thanks again.

[longhair]

I know people say you can't use a split charger on a custom but I have one fitted to my 2014 limited camper and it charges my 110amp leisure battery quickly with no problems at all, so I don't know where that idea comes from that you have to use a b2b charger. My vsr has worked fine for the 3years I have had the van.

[bortaf]

It's the quickly part that can be an issue, basicly a VSR split charge relay sends the full alt voltage to both batterys when it's engauged, on a smart charge system the voltage can be too high for a normal SLA leasure battery (hense Calcium batterys are used in the vehical) the B2B allows that higher voltage to be dropped to a safer level for the leasure battery chemistry, you can use a VSR but it will probably shorten the leasure batterys life span, if your running a single sub £100 battery it's no biggy to replace it every 4 or 5 years but if your running 2 or 3 £150+ AGMs it's more of an issue for the future.

[Doug24]

Some further questions for "bortaf", hope that's OK.

I like the Renogy DCC50S that you suggest, particularly as solar may be added later.

However, the manual talks about having to connect an "IGN" wire to the vehicle ignition for smart alternators. Our skills aren't up to messing with the wiring loom! How/where did you connect the IGN cable in your installation?

Also, if we place the second leisure battery at the rear of the van, in the "garage" area approx. 3m from the drivers seat, what gauge of cable would you suggest? Is it necessary to run the negative connection all the way back to the front, or can we connect the leisure battery negative to a body earthing point close by?

Thanks in advance. Really useful information for "newbies".

Doug

[bortaf]

TBH my Mk7 had a euro5 delete option ticked when it was orderd new (but i still have the 2 battery set up) so i dont have a smart alt but i'm sure there's an ign live under the drivers seat i've used in the past, i used 35mm wire to my leasure battery but that was because it was already there i would use 16mm, bigger if you can? 16mm is good for up to 70amps at that lenght of run and you should only have 50 amps max with alt and solar, note that the renogy is 25A solar and 25A alt so if you dont go for solar later there are cheeper options that will charge faster off just the alt, have a look at the graph below for cable rarings ect