Charging the Van battery- chassis earth point

[Jonathanvwt6]

Hi all, really hoping someone can help me. I am wanting to keep my van battery (not leisure battery) topped up with a smart charger and believe that you shouldn’t put the negative clip onto the battery itself. Everywhere says to attach the negative clip onto a chassis earth point, but I have no idea where this is and cannot for the life in me find anything with an image online to show me. Anyone have a picture of where this would be in the engine bay????

 

[TallPaul_S]

Hi all, really hoping someone can help me. I am wanting to keep my van battery (not leisure battery) topped up with a smart charger and believe that you shouldn’t put the negative clip onto the battery itself. Everywhere says to attach the negative clip onto a chassis earth point, but I have no idea where this is and cannot for the life in me find anything with an image online to show me. Anyone have a picture of where this would be in the engine bay????

Are you just using the crocodile clips? There's a few bolt heads around the battery bay that will work fine.

Alternatively, if your charger is 10a or less, you can charge via the dash 12v socket that's connected to the SB and permanently live.

It also keeps everything inside the van, I either run an extension through a window to the charger on the passenger seat then to the 12v socket, or if I've got the van plugged in via hookup I then plug the SB charger into an interior 240n plug. That means both batteries are getting charged.

 

[Jonathanvwt6]

Are you just using the crocodile clips? There's a few bolt heads around the battery bay that will work fine.

Alternatively, if your charger is 10a or less, you can charge via the dash 12v socket that's connected to the SB and permanently live.

It also keeps everything inside the van, I either run an extension through a window to the charger on the passenger seat then to the 12v socket, or if I've got the van plugged in via hookup I then plug the SB charger into an interior 240n plug. That means both batteries are getting charged.

Thanks for the reply. I haven’t got the smart charger yet but have you any recommendations on a smart charger that doesn’t cost the earth that fits into the 12v socket? I like the idea of charging from the inside of the van!

 

[TallPaul_S]

Thanks for the reply. I haven’t got the smart charger yet but have you any recommendations on a smart charger that doesn’t cost the earth that fits into the 12v socket? I like the idea of charging from the inside of the van!

If it's just for topping up the SB then 5 or 10a is plenty, either if it's been sitting for a while or when you're camping for a few days and don't want the unlocking/opening doors to flatten the SB.

I've got a Victron ip65 12/5 charger and 12v adapter which does the job perfectly. That's about £80-90 all in.



Bluetooth is very handy on these as it means you can check on the charging state from inside the house rather than having to go out into the rain/cold/wind

 

[Dellmassive]

see here:

Battery Charging - Main Battery Chassis Point -

Battery Charging - Main Battery Earth Point - so weve all be told NOT to bridge out the battery monitor on the neg side of the battery when charging it. This is so the ECM can correctly gauge the SOC (state of charge) of the starter battery by monitoring the current flow in and out of the...

www.t6forum.com

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[dcpen43]

I cannot believe how stupid i have been. For a while I have been pondering why the output from my Victon Ac and MPPT chargers show a 1volt difference between their outputs and the reading across the VB terminals but not across the LB.

i put it down to all sorts: cable length, my complicated break before make charge switching, bulk charging thresholds and even the VB bms.

I forgot the blindingly obvious; no common earth. I naively assumed the LB would be grounded but it was not. A simple grounding wire and low and behold all voltages align.

 

[Dellmassive]

I cannot believe how stupid i have been. For a while I have been pondering why the output from my Victon Ac and MPPT chargers show a 1volt difference between their outputs and the reading across the VB terminals but not across the LB.

i put it down to all sorts: cable length, my complicated break before make charge switching, bulk charging thresholds and even the VB bms.

I forgot the blindingly obvious; no common earth. I naively assumed the LB would be grounded but it was not. A simple grounding wire and low and behold all voltages align.

Pictures tell a 1000 words and all that....

Drop a pic.

 

[dcpen43]

Pictures tell a 1000 words and all that....

Drop a pic.

In my Van i have put a cross over switch which allows me to charge one battery with solar at the same time charge the other via the EHU. iam using a changeover switch.

Previously there was hardly any voltage difference between the charging sources and the LB but there was a 1v difference between them and the VB.

You can see from the pictures by adding a common ground there is hardly any voltage difference now between charging sources and both batteries.

VB bms is connected to battery terminals. Likewise for LB. Digital volt readers connected at charging source (VB left hand dial).

Volt difference now makes sense because LB circuit was not grounded to the chassis. It is now.