How-To install DC-DC charger to replace VW Split Charge relay

[AlanC]

Perhaps some confusion here. Leisure batteries are not (or should not be) lead acid but Gel type. Starter battery is leadvacid obvs.

No problem at all leaving van on hook up.

As the batteries on a Cali, both beach and SE/Ocean, are charged by the same system they all have the same chemistry, lead plates submerged in an electrolyte which in this case is sulfuric acid. So all the batteries contain sulfuric acid in some form or another, either as a liquid, gel or AGM.

AGM stands for Absorbed Glass Mat and is only a method of having a solid form of sulfuric acid in the battery as opposed to liquid acid.

Alan

 

[sidepod]

What I was getting at was that leisure batteries should be the type that don’t gas whilst being charged.

 

[burnercan]

leisure batteries should be the type that don’t gas whilst being charged.

Isn’t that what the vent hose/pipe is for?


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[Walrus]

An interesting thread. I even understood bits of it. My solar panel does a great job of keeping the Leisure batteries at around 100% most of the time. I seem to understand from what you say above that the LBs will also trickle charge the starter battery if they are above 80 %. Or have I understood even less than I thought?

 

[Loz]

An interesting thread. I even understood bits of it. My solar panel does a great job of keeping the Leisure batteries at around 100% most of the time. I seem to understand from what you say above that the LBs will also trickle charge the starter battery if they are above 80 %. Or have I understood even less than I thought?

If your solar charger is only connected to the leisure batteries then it will not trickle charge the starter battery.

 

[marchugo]

Loz, Excellent description of a remarkable solution to a system design flaw of VW.

Now that your alternator is doing overhours to top up the leisure bats, how much did your mileage go up?
The blumotion system was invented as a trick to keep the van in range of the Euro 6 pollution bounderies. It might be that your van now is exceeding Nox and C02 emission standards?

Could this be a problem during MOD tests, where Nox and CO2 are measured?

Solution: Arrive at the MOD with fully topped up leasure batteries....

OT: BTW, did you take a picture of where the gas ventilation hoses disappear in the vans bottom/sidewalls? In my T5 the little ventilation hose of the batterie in the back just hangs loose in the compartment. I can’t find the ventilations hole in the body.

Regards from Amsterdam,
Marc.

 

[Amarillo]

If your solar charger is only connected to the leisure batteries then it will not trickle charge the starter battery.

One of the things I intend to do on our return to the UK is fit a split charge for my solar. I can only see benefits in having my 200 watts of solar deliver a float charge to leisure and starter battery while sitting on my driveway.


Follow my blog: www.au-revoir.eu

 

[Walrus]

If your solar charger is only connected to the leisure batteries then it will not trickle charge the starter battery.

I thought that was too good to be true. Thank you.

 

[AlanC]

What I was getting at was that leisure batteries should be the type that don’t gas whilst being charged.

All Lead Acid batteries will give off gas when being charged to some extent. So called ‘sealed’ batteries are usually gel or AGM which, by virtue of the solid electrolyte, given off smaller amounts of gas as they can’t bubble, which liquid sulphuric acid does, when charged.

So they still need to be ventilated. In our case via the small rubber tube passing through the floor under the seat. I am not certain of the route of the tube for the rear battery either.

In days gone by, we always had to top up the acid in each cell with distilled water. The caps to each cell had small holes in them to ventilate the cell.

Showing my age now!

Alan

 

[rod_vw]

Excellent write-up Loz, my only comment would be to go to the trouble of locating the earth stud under the floor covering. For the benefit of others there is a similar stud under both seats.

I am using the RING RSCDC30 DC-DC converter which includes a MPPT solar panel controller. It's a bit bulky but will sit under the drivers seat (just about). Having had this system and simple split charge & simple solar controllers in the past I can confirm that the DC-DC and MPPT are superior.

Rod

 

[Cumbrian_Cali]

Great how-to guide.
However for those cautious of upsetting the VW warranty man; leaving one of the heated seats on whilst driving overrides the BMT and attains and maintains full charge in the leisure batteries.

 

[rod_vw]

Great how-to guide.
However for those cautious of upsetting the VW warranty man; leaving one of the heated seats on whilst driving overrides the BMT and attains and maintains full charge in the leisure batteries.

Now there's a thought, does the same apply when the heated screen (either) are on? I'll have to try it.

 

[Cumbrian_Cali]

Now there's a thought, does the same apply when the heated screen (either) are on? I'll have to try it.

The heated screen switches off after a predefined time whereas the seats stay on

 

[rod_vw]

Only if you have them!

 

[Cumbrian_Cali]

Only if you have them!

Can you get an ocean without heated seats?

 

[California Dreamin]

Fantastic write up Loz, only just seen this (having just popped and MPPT under the driver's seat) but will now do this too. Nice one.

 

[jcshnz]

Twice in the last 3 days our new to us (2011) océan has had a flat engine battery in the morning. The 2 house batteries have just been renewed and a test of the engine battery indicated it was fine. When we get home I’ll attempt to find any voltage leaks. But, I’d like to implement a link switch for thé 2 battery systems in the case this happens again. Or some other trickery. Any ideas chaps?
Cheers james

 

[Loz]

But, I’d like to implement a link switch for thé 2 battery systems in the case this happens again. Or some other trickery. Any ideas chaps?
Cheers james

The cables for the aux battery charger and not large enough for jump starting, so this is not a safe option.

You would be better with a small Lithium power pack.

How old is the starter battery? If it is the original it is probably time to replace it.

 

[WelshGas]

Twice in the last 3 days our new to us (2011) océan has had a flat engine battery in the morning. The 2 house batteries have just been renewed and a test of the engine battery indicated it was fine. When we get home I’ll attempt to find any voltage leaks. But, I’d like to implement a link switch for thé 2 battery systems in the case this happens again. Or some other trickery. Any ideas chaps?
Cheers james

Have you been using the In Car Music/Radio system a lot whilst camping without Hookup?
Do you have an electrically operated sliding Door?
Did you switch Off the Driving Cab lights, the ones that operate when the cab doors/sliding door open, whilst camping?
Did you use the Dashboard 12v socket for anything?

All these run off the Engine Battery. Also some aftermarket radio/music systems can cause a parasitic drain off the engine battery.

As @Loz has said, a Lithium Starter pack is a useful addition.

 

[jcshnz]

The s

The cables for the aux battery charger and not large enough for jump starting, so this is not a safe option.

You would be better with a small Lithium power pack.

How old is the starter battery? If it is the original it is probably time to replace it.

hi, thé starter battery has been tested and passed. I’m aware of the current draw items too. Without pulling it allé to pieces (yet) I was wondering if a simple high current switch could be installed between the 2 battery circuits to link them for starting. ... I used a simple electronic split charger relay on my defender and it had a low current switch to link the circuits. It’s been invaluable. But I gather from the above discussion re canbus that this might be unusable on this higher tech system. Or might it?
Or, could an extension circuit be applied to the 12v to 12v charger circuit above to link the 2 systems the other way as it were. ? In the latter case I wouldn’t be looking to start the vehicle using the low current link wires, just to feed some charge back to the starter battery to top it up. Another thought is maybe try to source a device that cuts off the engine battert when it drops to a certain level. I’ve heard about these but never seen one ... cheers for all advices

 

[WelshGas]

The s

hi, thé starter battery has been tested and passed. I’m aware of the current draw items too. Without pulling it allé to pieces (yet) I was wondering if a simple high current switch could be installed between the 2 battery circuits to link them for starting. ... I used a simple electronic split charger relay on my defender and it had a low current switch to link the circuits. It’s been invaluable. But I gather from the above discussion re canbus that this might be unusable on this higher tech system. Or might it?
Or, could an extension circuit be applied to the 12v to 12v charger circuit above to link the 2 systems the other way as it were. ? In the latter case I wouldn’t be looking to start the vehicle using the low current link wires, just to feed some charge back to the starter battery to top it up. Another thought is maybe try to source a device that cuts off the engine battert when it drops to a certain level. I’ve heard about these but never seen one ... cheers for all advices

Something like that has/can be done by fitting an Anderson Socket to the front Leisure Battery and using a set of Starter leads fitted with an Anderson Plug. The Starter leads then connected to the + pole of the Engine Battery and an Earthing point within the Engine compartment ( NOT the - pole to avoid screwing up the electronic battery monitoring ).

BUT, before messing around with such a system I would concentrate on why the Engine Battery failed 2 x in 3 days. Not normal by any stretch of the imagination. How old is the battery? It might seem OK but really needs to be stress tested and not just have the voltage tested. Mine has lasted in excess of 4 weeks when parked at Heathrow with alarm on, admittedly no one was opening doors etc.

Having gone flat twice this has probably caused damage and either the battery is on the way out or there is a parasitic drain.

Also, if the Engine Battery has been replaced was the replacement battery synced to the vehicle?
Gone are the days where you just popped in a new battery and away you go. I don't know if this applies to a 2011 vehicle but it certainly does to later vehicles with the BlueMotion package.

 

[Legin]

Excellent write-up Loz, my only comment would be to go to the trouble of locating the earth stud under the floor covering. For the benefit of others there is a similar stud under both seats.

I am using the RING RSCDC30 DC-DC converter which includes a MPPT solar panel controller. It's a bit bulky but will sit under the drivers seat (just about). Having had this system and simple split charge & simple solar controllers in the past I can confirm that the DC-DC and MPPT are superior.

Rod

That Ring unit looks good on the face of it however many reports of charging issues when using solar locking out the supply battery. Was a firmware update but even then some reports of occasional problems and need to disconnect the pv to reset. Do you have any such problems ?

 

[sidepod]

Err did anyone point out that leisure batteries are different from starter batteries and not suitable for engine cranking?

 

[WelshGas]

Err did anyone point out that leisure batteries are different from starter batteries and not suitable for engine cranking?

Has been mentioned, but you can use them to top up the charge in the engine battery, connect and wait 10 minutes or so, disconnect and then crank engine.

 

[jcshnz]

Err did anyone point out that leisure batteries are different from starter batteries and not suitable for engine cranking?

Ice researched this and it appears vw specify dual purpose batteries and they are ok for starting.