Best earth point for all leisure electrics?

Deaks

Deaks

Senior Member
VIP Member
T6 Pro
I’m getting close to installing all my leisure electrics, which is mostly Victron based.
The two 130 Ah valence lithium batteries will be housed in the kitchen furniture, near the rear wheel arch (just in front to be precise).
All of the kit will connect to a hefty negative bus bar that has the Victron bmv-712 shunt fitted, so I need to find a good earthing point.
On the rear quarter is a little m6 stud that the rear light clusters connect to, but I’m thinking I need something a bit more substantial.
So I was wondering if the previous tie down point (see picture) which is a m10 thread into a bulky part of the chassis.
Would this be suitable?

TIA

Deaks :) D3080D4E-BDD1-4808-A54D-5934E20D7A97.jpeg
 
Looking at some figures online suggests that 6mm studs can take 125 amps but i'm not going to bet on that! Admittedly that doesn't account for the earthed surface/contact area that the stud is clamping the terminals to so it could feasibly be much higher if you were really going to town!

On a slight tangent..... that existing tie down point looks suspiciously like a seatbelt mounting point. I was sure that these were 7/16 UNF by law but a bit of research suggests that many manufacturers went metric some time ago....:oops:
Why does this matter? Well, I fitted tiedown points with 7/16 bolts to the redundant seatbelt holes in my van and they appeared to fit quite well. Looking at the specs for M10 vs 7/16 suggests that they aren't coincidentally similar so i don't know if your M10 would be safe as a tie down or otherwise?
Happy to be corrected of course and I'll gladly replace mine as M10 are easier to find in a nice finish.
 
With a circle of paint buzzed off and a bit of grease applied to prevent corrosion, a welded nut onto the chassis is a good earth point. That said, on my T30 SWB the anchor points were screwed into L shaped brackets pop riveted under the floor!

My van has an earth post at the o/s D pillar and one under each front seat. They are welded in and designed to take a ring connector.

Ian
 
I always use the welded on 6mm studs under the front seats plus there is one on the left side panel reinforcement at the rear. Maybe one on the right side as well.

My incoming 240v hook-up connection has its earth (green/yellow) on the rear left one but the anomaly is that there is also a 12v -ve connection there which is Brown as DIN standard for such a wire! It looks crazy with the two standards on the same chassis stud but both are correct for the relevant standards!
 
Deaks said:
I’m getting close to installing all my leisure electrics, which is mostly Victron based.
The two 130 Ah valence lithium batteries will be housed in the kitchen furniture, near the rear wheel arch (just in front to be precise).
All of the kit will connect to a hefty negative bus bar that has the Victron bmv-712 shunt fitted, so I need to find a good earthing point.
On the rear quarter is a little m6 stud that the rear light clusters connect to, but I’m thinking I need something a bit more substantial.
So I was wondering if the previous tie down point (see picture) which is a m10 thread into a bulky part of the chassis.
Would this be suitable?

TIA

Deaks :) View attachment 79122
Click to expand...
Hi ..as a VIP member ...after typing in earth points ( search ) a whole host of resources can be downloaded that may be the solution you require
 
Have you thought about how the batteries are anchored ? Two 130AH batteries could be a lethal amount of inertia in an accident.
 
rover220 said:
lithium so not as heavy.
Click to expand...
I wonder, why do you wear your seat belt? because its a legal requirement or because it might save your life when your body continues into the bulkhead as the van decelerates in an instant? :) 40kg untethered is potentially lethal, they absolutely need securing properly :)
 
Phil_G said:
Have you thought about how the batteries are anchored ? Two 130AH batteries could be a lethal amount of inertia in an accident.
Click to expand...
The batteries will be in a frame that is bolted to the unwin rail in the floor, so if the batteries come out of there, I'm probably dead at that point away!!
Just to clarify, the point I am looking to fix the 'master' earth point into is no longer used as a tie down or seat belt point, it would be an exclusive meaty earth point.
The rail on the far right will be covered by the kitchen furniture soon (hopefully).

IMG_0094.jpg

Deaks :)
 
hiya @Deaks just nosying at this thread as i have the same flooring theory...

questions... flush rails like mine...

9mm ply in gaps on floor... then 10mm ply for floor?
raise rails up a nats on washers along their length?

i have put my spare front double in the rear with an inch taken out of the rear height... pics to follow if you like..

just wondering how you got on with it..what you fitting on them?

thanks chris
 
T6DSGChris said:
hiya @Deaks just nosying at this thread as i have the same flooring theory...

questions... flush rails like mine...

9mm ply in gaps on floor... then 10mm ply for floor?
raise rails up a nats on washers along their length?

i have put my spare front double in the rear with an inch taken out of the rear height... pics to follow if you like..

just wondering how you got on with it..what you fitting on them?

thanks chris
Click to expand...
Hi Chris

The ply floor is 12mm not 10mm then the altro flooring on top.
To be honest it was quite a job, but well worth it. One company (unamed) wanted nearly 3k to fit them!!!!!!!!
I think there are 80 bolts holding down the rails in total.
I made up some spacers for the low points that did not have a ply packer underneath.
I did find that I had to adjust some of the spacers a bit, what I found really useful was a short piece of rail (6 inches or so) that I could drop in the slot and then check measure the gap with a steel rule in front of the edge.
I found that taking 1mm of the measurement ensured that the rail sat nice in the slot and was not proud at all.
Working out where the cross members are and trying to avoid a fixing there is key, its not a job to rush for sure!

I would be interested in seeing the twin seat setup, there are times when the option for a couple of more seats would be useful.

Deaks :cool:

IMG_0045.JPEGIMG_0096.JPEGIMG_0095.JPEGIMG_0050.JPEGIMG_0045.JPEG
 
hi mate rails are down on "first fix"
I had a spare base and seat so used these for my seat mods... i have the leather seat parts up in loft of house as i know i'll just damage them in the conversion...damaged a front one prior...never again...
think my left rail is same as yours but other is dead in centre...i was going to do all way to back and on other side but due to pod and my drop down bed idea im unsure...
my first fix was "bolted in front half" of rails...
will get some pics to show...

cheers chris
 
@Deaks did you use the lashing point for the earth in the end? Just about to do the same set up myself. I thought @Paynewright s suggestion was good enough. I'm sure I've seen some pictures on here when people have a done this
 
I'm guessing that all the van is linked and as long as you have a good metal to metal earth then you can earth anywhere?
 
@Mat T essentially yes but I would refrain from using an existing (in use) fastener. Obviously you want the shortest run possible but if you are within easy reach of the numerous factory fit earth points it makes sense to use one of those.
 
Mat T said:
I'm guessing that all the van is linked and as long as you have a good metal to metal earth then you can earth anywhere?
Click to expand...
Yes I did earth to the lashing point that would be the seat belt fixing in a kombi.
it’s a very substantial m10 fixing.
I used 120mm2 (4/0) cable direct to my negative bus bar and victron shunt.
 
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