Battery question

[SP8]

Hi all. Hope you can help with a battery question. I have a 2008 van with a factory fitted split charge system which I converted to a camper 4 or 5 years ago. The two batteries are both standard vehicle batteries and were new at the time of conversion. It looks like the auxillary battery may be knackered, I'm waiting for my son to come and test it. Over the years it has been flattened a few times so it may well be done. I'm thinking of getting a deep cycle battery to replace it with. Firstly I need to know if this would cause problems with the vehicle battery being a standard one and secondly can anyone recommend a good battery to get which will fit in the battery compartment with the vehicle battery. Thanks

Pete

[Altransit]

Ideally, the batteries should be the same capacity and type, and age, because it's not a split charge system, they are charged in parallel, and separated when switched off.
Different batteries may have different charge rates, which will affect the charging of the other one, especially if one is charged and one isn't, often the case in a Mk7 with two batteries.

[dumper]

Personally I wouldn’t use the van batteries to power the camper I use a split change and leisure battery but as you have had no problems for 5 years maybe ok.

[Cheet22]

Dumper,

Do you mean don't touch the two van batteries at all..ie, don't even add a split charge from them to my new leisure battery i plan to locate in rear for camper lights and power (with solarv and hook up connected to it)?

I like the idea of totally ignoring the van batteries to be honest, but will i regret/miss not charging my separate battery off engine?

[dumper]

No mate use a B2B charger like a Sterling I use a 30 amp one it’s feed off the van battery as mine hasn’t got the plug on the side of the drivers seat some also use a solar set up as well.

[Cheet22]

Sorry to be dumb.. But am i right here:

New leisure battery installed and connected as:
1. Solar charging panels connected to new leisure battery via mppt
2. Electric hookup socket fitted to van to allow mains battery charger connected to leisure battery
3. Also connect new leisure battery to main starter battery terminals (rearmost one under drivers seat) via split charge relay

This means i have 3 ways of charging my new leisure battery, right?

Sound right?

[bortaf]

Sounds right to me, do you already have the solar charger ?
As for the front battery i use one of those dsah top solar pannels to keep it charged, it runs the alarm, CL and radio ect so gets drined if left unstarted for more than a few weeks, i would allways change them as a pair TBH, 1 new and 1 old abttery is still an unmatched pair and may cause issue down the line ?

[Airthies]

3. Also connect new leisure battery to main starter battery terminals (rearmost one under drivers seat) via split charge relay

No, recommended in BEMM to connect to front "aux" battery.

This means i have 3 ways of charging my new leisure battery, right?

Sound right?

Yes.

Sent from my A55ho11 using Crapatalk

[HarstL]

My two cents are: get at least a deep cycle battery (AGM or Gel) or ,if you want to spend the money, go for a LiFePO4 battery. The latter is more expensive, but can be drained down to 95% of its capacity without damage so you can do with half the capacity of of a lead based battery. Whatever you choose, get the appropriate charging installation for the battery of your choice. Car batteries are not constructed to be discharged too much and will deteriorate quickly (I found out the hard way) if drained too much.
I found it worth the investment after it took weeks to get rid of the "eggs gone bad" smell as a result from an unnoticed short circuit that fried my battery...
But whatever you choose, happy camping!

[Cheet22]

Thanks folks..

I'm still a little unsure of if/how to connect to vehicles original 2 batteries

I've got a 500w solar system on order, with a 40A mppt. I also plan to install an electric hookup with a mains battery charger.

Both these will connect to one or two completely new leisure batteries.

I plan to install a number of 12v lights, sockets, mainly to charge kids devices and phones. I also plan a 12v tv, an electric water pump. Id like to occasionally use laptop so will need to charge that once in a while. Also a diesel heater.

I've also swapped front seats and so have a battery box under passenger seat same as drivers.

We plan to use the van for long weekends rather than long holidays, but who knows, that depends on wife and kids really and how they like it.

So, my questions I'd still love advice on (and sorry for keep asking the first)

1. Should i also charge the new battery/batteries by connecting to van batteries? Is that a b2b or a split charger i need? And do i deffo connect to front van battery terminals?

2. Has anyone else put new batteries/battery under passenger seat? Did you run cables along floor between drivers and passengers seats, and up the A post to roof solar panels? Or would you recommend just leaving passenger seat box and put new battery/batteries in rear?

3. For my usage, would a single 110ah work? Seen some great prices in superbatt 110ah - 3 for £203! - but they are not agm of course.

Again sorry for asking again on the first, just not quite sure if i should connect to van batteries at all, and if so, exactly how.

[dumper]

My b2b is connected to the auxiliary battery the 2 110 amp leisure batteries are used to power everything in my van I use it for radio Marshaling on car rallies to give you a idea of what power I use on a weekend away Saturday afternoon drive to the venue so the leisure batteries are at full charge so when parked up out with the beer turn on the tv and start up the night heater on average 6to7 hours when I go to bed the only thing running will be the radio in the back. In the morning the van engine will be run for 30 minutes max while getting into location switch on two two way radios and the night heater for upto 10 hours and I will have used the 1600 W inverter to run the 500 W microwave for a maximum of 12 minutes over the weekend the lights are led and water pump will use very little I have never flattened them .
My first van ran off a standard mk3 starter battery it would need the van running up during the day to keep the heater running and it didn’t have the inverter back then everything in the van used to need more power to run things unlike today with modern electrics hope this gives you an idea of what I use on wild camping.

[Cheet22]

Cheers once again dumper

[dumper]

No problem hope my ramblings help.

[Airthies]

You can put batteries anywhere you like, if under the passenger seat there's enough room in the cable tray to to get an extra battery cable and the tray runs under the mat to the passenger side. You will need to lift the cab mat to access it though.

There's room just under the B pillar trim (past the seatbelt) to run cables up to the roof discreetly.

B2B charger or split charge VSR will be fine to charge leasure batteries, connected to front van battery.
Van batteries should be STD cranking batts.

With two leasure batts and solar charging I think you'd have to go some to flatten everything, but as with anything go a big as you can on the solar panels at the start.

Sent from my A55ho11 using Crapatalk

[Cheet22]

Thanks Airthies.

Mat is already out, it was not in a good state so i took it out after removing front passenger seat. I've actually swapped front seats for two bmw e46 seats - and they are much better.

So i got a new battery box for passenger, so got space for two there. I'm going to need to run cables from van battery to these, then from New batteries up the b pillar as you say, so i can mount the solar controllar, inverter, etc somewhere out the way.

Can i indeed just use a split charge kit then connected to front battery rather than a b2b? Just looking for lowest cost option.