Engine battery charging using leisure battery?

[Rioja John]

I fitted a CSB2 to charge my vehicle battery from leisure battery it cost £34 plus postage and dead easy to fit.

John.

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[Deaky]

Is this definitely right? There should not be anything connected to the -ve terminal of the starter battery!
This was fitted by the company that converted the van so I would only disconnect this if it is absolutely definitely incorrectly connected.

Yes, it’s absolutely definitely incorrectly connected. Remove it from the battery and connect it to a nearby earth stud.

 

[Mattsuze]

Thanks everyone, that may be a much simpler fix and save having to fork out for new gadgets!

 

[Mattsuze]

I’ve had another look under the bonnet at the starter battery terminals. On the negative terminal is what looks like the VW-fitted connection which presumably leads down to a grounding point on the chassis. Then there is the campervan ‘add-on’ also connected to the -ve terminal.
As the -ve is connected to the chassis, doesn’t that mean the new cable on the -ve terminal is also connected to the chassis, just at a point at the terminal itself? What difference would moving it to a bolt off the battery itself make and why/how does this make a difference?

 

[Oceanis]

I’ve had another look under the bonnet at the starter battery terminals. On the negative terminal is what looks like the VW-fitted connection which presumably leads down to a grounding point on the chassis. Then there is the campervan ‘add-on’ also connected to the -ve terminal.
As the -ve is connected to the chassis, doesn’t that mean the new cable on the -ve terminal is also connected to the chassis, just at a point at the terminal itself? What difference would moving it to a bolt off the battery itself make and why/how does this make a difference?

View attachment 169969

The white component attached to the terminal is a shunt. This is used by the VW charging and recuperation system to determine how much current is going in and out of the battery. The camper van add-on has bypassed this, providing a current path that the VW logic doesn't know about and effectively screwing up its battery state of charge calculations.

The rule is that everything going in or out a the battery must go through the shunt if it is fitted, otherwise the shunt, and the calculations based on its measurements, are rendered useless and any systems relying on the shunt info will be compromised and will not work as intended.

Moving this connection to another chassis ground point will mean that all the current in and out of the battery will go through the shunt as VW intended.

 

[Mattsuze]

I fitted a CSB2 to charge my vehicle battery from leisure battery it cost £34 plus postage and dead easy to fit.

John.

What Have You Done To Your Van Today?

Fitted a 2nd hand Karitek side load roof rack with canoe j cradles this week … great solid British engineering How are you finding the Karitek? I'm waiting for a quote off them for my T6 with a Skyline top. I have the Thule Hullavator on the car but waiting to get the van back from the...

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Hi John, when looking up the CSB2, a page came up showing a government recall due to fire risks. Product Recall: CBE CSB2 / CSB2-LT Battery Chargers (2208-0209)
Be worth checking this out further and perhaps considering swapping it for something else.

 

[Deaky]

I’ve had another look under the bonnet at the starter battery terminals. On the negative terminal is what looks like the VW-fitted connection which presumably leads down to a grounding point on the chassis. Then there is the campervan ‘add-on’ also connected to the -ve terminal.
As the -ve is connected to the chassis, doesn’t that mean the new cable on the -ve terminal is also connected to the chassis, just at a point at the terminal itself? What difference would moving it to a bolt off the battery itself make and why/how does this make a difference?

View attachment 169969

Simply put....

It's all to do with the smart alternator. The module on the side of the -ve terminal is a shunt. It monitors the amps in and out of the battery. This way the van knows the SOC (state of charge) of the battery. This means it can turn the alternator off when not needed.

So the van will count the amps out of the starter battery and put the same amount back in via the alternator. Any connections before the shunt will not be counted If there are amps being taken out of the battery that are not counted, then these won't get put back in. Eventually your battery will run flat.

 

[Salty Spuds]

Simply put....

It's all to do with the smart alternator. The module on the side of the -ve terminal is a shunt. It monitors the amps in and out of the battery. This way the van knows the SOC (state of charge) of the battery. This means it can turn the alternator off when not needed.

So the van will count the amps out of the starter battery and put the same amount back in via the alternator. Any connections before the shunt will not be counted If there are amps being taken out of the battery that are not counted, then these won't get put back in. Eventually your battery will run flat.

Nicely put sir

 

[Mattsuze]

Seems pretty clear - I’ll have a play today, see if I can quickly move the extra connection to a bolt on the chassis.
Thanks all again.

 

[Mattsuze]

Sorry, pestering now…
Do your know whether any of the bills shown in the attached pictures would be suitable and are connected directly to the chassis?
Where the existing shunt is connected to the chassis is tucked away and pretty inaccessible.

 

[Oceanis]

Sorry, pestering now…
Do your know whether any of the bills shown in the attached pictures would be suitable and are connected directly to the chassis?
Where the existing shunt is connected to the chassis is tucked away and pretty inaccessible.

View attachment 169972

View attachment 169973

View attachment 169974

Do you have a multi-meter?

If you do, put it on resistance or continuity measurement and measure from the battery pole to the bolts you have identified. You are looking for a resistance under 0.01 Ohms or less. Bolt it to the lowest resistance bolt.

As a rule, always look for a chassis ground on metal parts that are welded to the rest of the car, bolt on wings or other bolt-on components are not as good - they will work, but you can't beat continuous metal for electrical conductivity. Any bolted or clipped joint in an electrical circuit introduces a very small amount of resistance which generates a voltage drop.

 

[Rioja John]

Hi John, when looking up the CSB2, a page came up showing a government recall due to fire risks. Product Recall: CBE CSB2 / CSB2-LT Battery Chargers (2208-0209)
Be worth checking this out further and perhaps considering swapping it for something else.

Thanks @Mattsuze I posted the recall last week on here , I got in touch with the manufacturers and my CSB2 was new batch after those serial numbers which were faulty.
I've used the CSB2 on motorhomes in the past it’s simple to install and does it’s job charging the vehicle battery.
Once again thanks for your concern.

John.

 

[Mattsuze]

Thanks @Mattsuze I posted the recall last week on here , I got in touch with the manufacturers and my CSB2 was new batch after those serial numbers which were faulty.
I've used the CSB2 on motorhomes in the past it’s simple to install and does it’s job charging the vehicle battery.
Once again thanks for your concern.

John.

Good stuff, glad you’ve got the safe one!

 

[Dave F]

if I plug my camper in at home and the controller panel is switched off will it still charge the leisure battery and also will it charge the main battery as well .
when it’s really cold it won’t start as soon as I use the jump starter pack it fires up then it ok all day so I’m thinking if I plug it in at night hence the question above . Cheers

 

[CAB]

if I plug my camper in at home and the controller panel is switched off will it still charge the leisure battery and also will it charge the main battery as well .
when it’s really cold it won’t start as soon as I use the jump starter pack it fires up then it ok all day so I’m thinking if I plug it in at night hence the question above . Cheers

Get yourself a pair of BM2 battery monitors. Failing that, the plug in USB + voltage monitors are handy.

Battery Monitoring -- How I Done It --

Victron 2.41 FW update brings in live data feed on the status screen.... This is a great update from Victron. :thumbsup::thumbsup: Didn't try the Beta and waited for the full release to be available as been going away and didn't want to break the system!

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No idea on your system but presumably not when off, also unlikely to charge the starter. What does the control system manual say?

Edit :
This is mine after a fortnight turned off :

 

[CAB]

if I plug my camper in at home and the controller panel is switched off will it still charge the leisure battery and also will it charge the main battery as well .
when it’s really cold it won’t start as soon as I use the jump starter pack it fires up then it ok all day so I’m thinking if I plug it in at night hence the question above . Cheers

If it doesn't charge the starter, get a CTEK MXS 5.0 and plug it into your 230v and the dash.

Then you can charge both at once!

Like what I do!

 

[Dave F]

I can’t find the manual but this is what I have fitted next to the leisure battery then cables going back to the main battery I think

 

[Dellmassive]

No, the standard EHU and battery charger won't charge the starting battery.

But will charge the leisure battery.

 

[Dellmassive]

More info

[Guide] Battery Maintainer (for Starter battery) -- How I Done It --

[Guide] Battery Maintainer (for Starter battery) -- How I Done It -- Right so its that time of year again . . . . . . . . Winter & (Lockdown 2020) The van might be layed up not being used, which will lead to a flat battery in around 3 weeks. The cold weather doesn't help the battery's...

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[Dave F]

So where it says it will trickle charge the starter battery when the leisure battery is full that is only then you have solar panel fitted ?.
if so what is the smart pass 120s if that was connected with the D250se would that charge it when the van is connected to the mains .
Cheers