Our custom Lithium battery installation

[GTR guy]

I purchased a 200ah Renogy battery that I need to install which on my 21NE which means moving the battery inside. The current lead acid battery negative cable is run directly from the outdoor storage box to the trailer frame. When the battery is under the dinette, where and how do you ground the negative? I don't have much experience with electrical work and would hate to cause myself problems later on from a rookie mistake.

I looked at the bus bar where the other negative wires terminate and that is a) full and b) not grounded to anything I can see - it seems to just be screwed into the wood of the dinette. Is this something I need to change? If not, would grounding the battery be as simple as getting an additional bus bar and terminating the battery negative to this bar?

[John in Santa Cruz]

there should be a wire from the ground post on the back of the power center through the floor to the frame, that is the chassis ground.

here's the back of the power center on my E21C, under the center section of the u dinette... you can see two black wires going down off the pic, one of those is the ground that goes through the floor, I'm not sure what the other one is. Note this is after I added some DC power outlets seen to the right of the picture, but before my massive rewiring for my overkill lithium upgrade.



I opted to add another ground bus (and also a positive bus) to handle all the high current stuff, my batteries and solar and inverter are connected to these, and they in turn are connected to the power center. you can see these here, under the red and black plastic covers... These bus bars are rated for 250A, and my 2000W inverter can pull 180 amps, so they really aren't overkill.

[splitting_lanes]

Originally Posted by GTR guy

I looked at the bus bar where the other negative wires terminate and that is a) full and b) not grounded to anything I can see - it seems to just be screwed into the wood of the dinette. Is this something I need to change? If not, would grounding the battery be as simple as getting an additional bus bar and terminating the battery negative to this bar?

I replaced the full grounding bus bar with this:
https://www.amazon.com/dp/B0BJ9K2SFP...t_details&th=1

And in addition to the ground that runs to the frame, I added another ground from the battery directly to the bus bar. You can’t have too many grounds.

[John in Santa Cruz]

Originally Posted by splitting_lanes

I replaced the full grounding bus bar with this:
https://www.amazon.com/dp/B0BJ9K2SFP...t_details&th=1

And in addition to the ground that runs to the frame, I added another ground from the battery directly to the bus bar. You can’t have too many grounds.

actually, grounds should be like a 'tree' with only one path from any ground point to any other ground point. ground loops (other than parallel short heavy gauge wires) can cause funny things like pick up radio noise.

so from what you describe, I would wire the main battery negative directly to this bus strip, connect the existing chassis ground directly to it, and run a wire from the strip to the old ground post. or if you can, move ALL the ground wires from that crappy post to this strip so its the single point ground for the whole system.

[splitting_lanes]

Originally Posted by John in Santa Cruz

actually, grounds should be like a 'tree' with only one path from any ground point to any other ground point. ground loops (other than parallel short heavy gauge wires) can cause funny things like pick up radio noise.

so from what you describe, I would wire the main battery negative directly to this bus strip, connect the existing chassis ground directly to it, and run a wire from the strip to the old ground post. or if you can, move ALL the ground wires from that crappy post to this strip so its the single point ground for the whole system.

With AC, loops are bad, multiple paths are bad. But I don’t think that holds true with DC, nor is picking up radio signals a real issue, or we wouldn’t be using the frame as a ground point — cause that’s a giant antenna!

To the OP though, either way should work. And the battery connection to the ground bus is much better than to the frame, because it’s a shorter path.

[John in Santa Cruz]

ideally, the frame is only in the negative path for the tow vehicle charging power, the brakes, and the driving lights (which aren't otherwise connected to the trailer electrics).

[GTR guy]

Originally Posted by John in Santa Cruz

or if you can, move ALL the ground wires from that crappy post to this strip so its the single point ground for the whole system.

So would I be OK installing a larger bus bar such as the one linked by Splitting Lanes (the current one has no open positions for new connections), attaching the battery negative to this new bus bar along with moving all the negative wires from the old to the new bus bar? If my system was installed the same as yours was, I should still have the ground wire going the trailer frame for the ground. Will this be safe?

Sorry to be such a pest trying to get this right. I reached out to several RV repair firms but no one wants to work on the wiring for me. It seems that the only way forward is to bring my knowledge of 21V systems to a higher level.

[brroberts]

I’m sure you meant 12V DC. I’ve made typos too. It’s always a good thing to be more self sufficient. The wiring is not difficult, but does need to be done correctly.

Many RV dealers won’t want to work on what they don’t sell. However, most mobile RV Techs will work on anything, so that might help you find help. There are two close to where I live.

Also, you may want to skip some of the math initially, but there are free online resources like the one linked below that can teach you much.

https://www.victronenergy.com/upload...limited-EN.pdf

[rubicon327]

Originally Posted by GTR guy

So would I be OK installing a larger bus bar such as the one linked by Splitting Lanes (the current one has no open positions for new connections), attaching the battery negative to this new bus bar along with moving all the negative wires from the old to the new bus bar? If my system was installed the same as yours was, I should still have the ground wire going the trailer frame for the ground. Will this be safe?

Sorry to be such a pest trying to get this right. I reached out to several RV repair firms but no one wants to work on the wiring for me. It seems that the only way forward is to bring my knowledge of 21V systems to a higher level.

In a stock format all of the 12V DC grounds terminate on a single stud on the back of the WFCO power center. Sounds like yours might be modified. Personally I would rewire all DC grounds onto a bussbar like this that utilizes ring terminals under the screws. You can still use the WFCO stud too if needed if you have a jumper to the bussbar.
https://www.amazon.com/dp/B0091VHLW4...m?ie=UTF8&th=1

If you have a wire direct from your battery to this ground buss you’ll have a complete circuit and everything will work. A wire to the frame from the bussbar is done as a common reference. You are no longer relying on the frame as the ground path.

[rubicon327]

Originally Posted by brroberts

I’m sure you meant 12V DC. I’ve made typos too.

220. 221. Whatever it takes.

https://m.youtube.com/watch?v=YkMbzjPkR90

[DGLP]

Originally Posted by John in Santa Cruz

there should be a wire from the ground post on the back of the power center through the floor to the frame, that is the chassis ground.

here's the back of the power center on my E21C, under the center section of the u dinette... you can see two black wires going down off the pic, one of those is the ground that goes through the floor, I'm not sure what the other one is. Note this is after I added some DC power outlets seen to the right of the picture, but before my massive rewiring for my overkill lithium upgrade.



I opted to add another ground bus (and also a positive bus) to handle all the high current stuff, my batteries and solar and inverter are connected to these, and they in turn are connected to the power center. you can see these here, under the red and black plastic covers... These bus bars are rated for 250A, and my 2000W inverter can pull 180 amps, so they really aren't overkill.

Regarding the bus bar, these are the instructions from the WFCO manual, verbatim:

"As a last step, install a separate bus bar in a location behind the converter. This bus bar can be purchased from a local home center or hardware store. For the WF-8935/8945/8955, run an 8 AWG wire from the NEG- lug on the top left of the DC fuse board to this bus bar. For the
WF-8965/8975, run a 6 AWG wire. Connect the battery negative wire to this bus bar along with all the negative DC load wires. Also, run a wire from the bus bar to chassis ground."

I did not have a ground from the stud on the back of the power center to the frame. I had to drill a hole through the floor and add the ground cable. I also had to add the bus bar. The trailer came equipped with a ground from the battery to the frame and a ground from the inverter to the frame.

The before (original setup from ETI) and after (busbar added by me after delivery) photos are attached.

[rubicon327]

Originally Posted by DGLP

Regarding the bus bar, these are the instructions from the WFCO manual, verbatim:

"As a last step, install a separate bus bar in a location behind the converter. This bus bar can be purchased from a local home center or hardware store. For the WF-8935/8945/8955, run an 8 AWG wire from the NEG- lug on the top left of the DC fuse board to this bus bar. For the
WF-8965/8975, run a 6 AWG wire. Connect the battery negative wire to this bus bar along with all the negative DC load wires. Also, run a wire from the bus bar to chassis ground."

I did not have a ground from the stud on the back of the power center to the frame. I had to drill a hole through the floor and add the ground cable. I also had to add the bus bar. The trailer came equipped with a ground from the battery to the frame and a ground from the inverter to the frame.

The before (original setup from ETI) and after (busbar added by me after delivery) photos are attached.

Perfect. Thanks for the reminder that this is in the WFCO manual. ETI really needs to be adding a buss bar. This is on the project list as I noticed during my 12V wiring upgrades that the stacked grounds on one small stud were not ideal.

[rubicon327]

Originally Posted by DGLP

I did not have a ground from the stud on the back of the power center to the frame. I had to drill a hole through the floor and add the ground cable. I also had to add the bus bar. The trailer came equipped with a ground from the battery to the frame...

This is fine as you would also have a wire direct from the battery negative to the ground stud which was completing the circuit. A single frame ground at the battery would be fine in this case.

[Grasshog]

This is one of the most helpful post I’ve seen thanks for this. I’m trying to figure out if I can get a three-way fridge from escape. I thought they said that’s no longer available but saw that you have it in your post? Thanks again.

[splitting_lanes]

Originally Posted by Grasshog

This is one of the most helpful post I’ve seen thanks for this. I’m trying to figure out if I can get a three-way fridge from escape. I thought they said that’s no longer available but saw that you have it in your post? Thanks again.

We have a three-way in our 5.0. John from Santa Cruz ( and others) have a compressor fridge which can run on DC. The compressor fridges are more efficient, but can’t run on propane.

I’m unaware if ETI has stopped making three-way fridges an option.

[John in Santa Cruz]

their website says a 3-way 6 cu ft is the base fridge for the 21C, optional upgrade to compressor fridge. 5 cu ft 3-way base on the 19, optional compressor... i assume the rest are similar.

[rubicon327]

Originally Posted by Grasshog

I’m trying to figure out if I can get a three-way fridge from escape. I thought they said that’s no longer available but saw that you have it in your post? Thanks again.

Karl mentioned in a recent video that they are/were having some supply chain issues in procuring absorption fridges. He also talked about DC compressor fridges becoming more popular in the industry and eventually maybe an all-electric Escape option. I don’t think any of this was meant to imply that absorption fridges will disappear altogether.

[DGLP]

Originally Posted by rubicon327

This is fine as you would also have a wire direct from the battery negative to the ground stud which was completing the circuit. A single frame ground at the battery would be fine in this case.

Yes indeed. Per the WFCO instructions, I also installed a cable from the battery negative to the bus bar. That cable in combination with the cable from the busbar to the ground and the cable from the stud to the bus bar completed the circuit. Yet another hole to drill and more cable to run. I used 6 gauge Ancor Tinned Marine Grade Battery Cable from Powerwerx. It's a little pricey. I like its flexibility and it slid nicely through the holes in the floor.

The Forstner bits worked well in drilling through the fiberglass, after first drilling pilot holes for the additional cable.

[hugh]

Originally Posted by rubicon327

Perfect. Thanks for the reminder that this is in the WFCO manual. ETI really needs to be adding a buss bar. This is on the project list as I noticed during my 12V wiring upgrades that the stacked grounds on one small stud were not ideal.

I think they've added it now. Or at least, my 2022 21C came with a bus bar above the WFCO power center, with all the ground connected.

[DGLP]

Originally Posted by rubicon327

Perfect. Thanks for the reminder that this is in the WFCO manual. ETI really needs to be adding a buss bar. This is on the project list as I noticed during my 12V wiring upgrades that the stacked grounds on one small stud were not ideal.

Agreed. The bus bar should be a standard item.

It was difficult to remove the nut from the stud on the power center. I had to cut off part of the topmost ring connector to be able to square up the wrench with the nut. There was such a thick stack of connectors on the stud and the nut is small. Odd size too.