Sterling B2B earthing

[ojf10000]

Hi all. Fitting a sterling b2b charger and the manual states both the aux battery and b2b charger should be seperately earthed directly back to the starter battery (not via the chassis). In my case the aux battery and charger are both at back of the van so would mean running two separate earths which seems a bit of a chew. If its best not to use the chassis then fair enough but surely I could get away with running one earth between the batteries and take the charger earth from the aux battery? Presumably this is due to volt drop? Has anyone connected up differently to how Sterling advise?
I’m thinking I run one earth between batteries (slightly over sized), earth the charger to the aux battery and for belt and braces connect the aux battery to the chassis too which should solve any major volt drop issues?
Thanks

 

[Nigel W]

If you read through some other threads on this forum you will see that it is recommended not to connect anything at all to the negative battery terminal as it upsets the computer and causes a multitude of issues. (Assuming you have a T6 with regen braking etc.)
My Sterling is connected to the chassis and it works perfectly.
I will try to find you a link to the thread.

 

[ojf10000]

If you read through some other threads on this forum you will see that it is recommended not to connect anything at all to the negative battery terminal as it upsets the computer and causes a multitude of issues. (Assuming you have a T6 with regen braking etc.)
My Sterling is connected to the chassis and it works perfectly.
I will try to find you a link to the thread.

Thanks Nigel. It is indeed a T6.1, chassis sounds a lot easier to me!

 

[Nigel W]

Thanks Nigel. It is indeed a T6.1, chassis sounds a lot easier to me!

Here you go - it’s a good read

Starter Battery Wiring - VW Disagreement

Interesting one. I've had a few problems with my starter battery discharging (its a Varta, not a Moll so thats not the issue!). Basically my battery goes flat after around 5-7d inactivity. Thats pretty short imo. This was an issue before lockdown and is not just due to the extended hiatus. I've...

www.t6forum.com

 

[ojf10000]

Interesting indeed. Seems that Sterling need to sort out their manual! Thanks very much, you’ve saved me a lot of work and seemingly future problems!
To note i did try search for previous posts but there was so many it made my head spin!

 

[mmi]

Actually the resistance by using chassis is very low - you'd need really thick cable to achieve the same (in order of 50mm2).
A thread with some serious power feed + chassis resistance measurement:

https://www.t6forum.com/threads/alternator-upgrade.7618/post-120895

https://www.t6forum.com/threads/alternator-upgrade.7618/post-121036

 

[ojf10000]

Actually the resistance by using chassis is very low - you'd need really thick cable to achieve the same (iin order of 50mm2).
A thread with some serious power feed + chassis resistance measurement:

https://www.t6forum.com/threads/alternator-upgrade.7618/post-120895

https://www.t6forum.com/threads/alternator-upgrade.7618/post-121036

Cheers. Chassis it is! I’m an electrician so understand resistance, but not done much with autoelectrics. I was failing to see why running a cable would be better than using a chunk of metal which will have next to no resistance

 

[Nigel W]

Cheers. Chassis it is! I’m an electrician so understand resistance, but not done much with autoelectrics. I was failing to see why running a cable would be better than using a chunk of metal which will have next to no resistance

I think these chargers started life for marine engines where chassis grounding is very poor, especially in cutters and pirate galleons , they just haven’t thought to update for chariots.