Moving Lithium battery under Dinette in MLE22

[Jimander1]

I purchased a 100Ah lithium and am installing it under the dinette seat. Is it best to simply run wire to where the tongue junctions are? The original wire is 8ga, and I'll run 6ga. The original junctions are a bit of a cluster, so I may replace the junction with a buss bar. I was considering adding a buss under the dinette and shortening the run to the charge controller, but want to see what others have done. Would I gain anything by connecting closer to the CC? I may add more battery in the future.

[SolarPoweredRV]

I purchased a 100Ah lithium and am installing it under the dinette seat. Is it best to simply run wire to where the tongue junctions are? The original wire is 8ga, and I'll run 6ga. The original junctions are a bit of a cluster, so I may replace the junction with a buss bar. I was considering adding a buss under the dinette and shortening the run to the charge controller, but want to see what others have done. Would I gain anything by connecting closer to the CC? I may add more battery in the future.

Yes, you should shorten the wiring.

The wires on the tongue run back to a connection point closer to the Converter. You should run the wires from your new battery to that connection point.

Alternatively, you could connect your new battery to the same wires that are coming out of the Converter and then run those wires into your distribution panel.

Also, I recommend installing a cut-off switch at the batteries so you can disconnect the batteries completely from the coach.

PS: Congrats on your Lithium upgrade.

[Riverbug]

I did the same when we had our 22MLE. Definitely do not run the wire to the front. Run it through the rear of the dinette and that will put you 12" from the power panel/converter/charger and buss bars under the pantry cabinet. There's lots of room behind the power panel too. If you removed the board from the rear under dinette section and do some re-framing you could have a great space for an inverter, additional batteries, or whatever.

Now, when you connect the new wires from the power panel to your battery, leave those original wires to the tongue also connected. You'll need those for the power supply to the tongue jack. Snip off the connectors that were connected to the battery up front, or you can use them to power pegs that you can mount up front for an additional 12V power supply for accessories such as a portable air compressor. Have fun!

[Jimander1]

Thanks! I removed the circuit breaker panel and saw where the 8 gauge wire (that goes to the tongue junction) connects to the +12v circuit side. There is a 2nd wire terminal position below the 8ga (original battery in) where I can attach the + new battery wire. I'll keep the old 8ga attached so the junctions near the tongue remain energized. Also noticed the 10 position negative buss bar screwed to the floor. Should I attach the battery ground wire to an available position on the neg buss or to the chassis? There are 6 or so + wires connected at the tongue terminal that energize the emergency brakes, tongue jack, TPMS, and some other unswitched electronics. I think this is also where the tow vehicle charge wire within the 7 pin connector connects.

[SolarPoweredRV]

Thanks! I removed the circuit breaker panel and saw where the 8 gauge wire (that goes to the tongue junction) connects to the +12v circuit side. There is a 2nd wire terminal position below the 8ga (original battery in) where I can attach the + new battery wire. I'll keep the old 8ga attached so the junctions near the tongue remain energized. Also noticed the 10 position negative buss bar screwed to the floor. Should I attach the battery ground wire to an available position on the neg buss or to the chassis? There are 6 or so + wires connected at the tongue terminal that energize the emergency brakes, tongue jack, TPMS, and some other unswitched electronics. I think this is also where the tow vehicle charge wire within the 7 pin connector connects.

If you have a negative terminal next to the positive terminal behind the panel, I would attach there. Otherwise, I would recommend you attach to the Buss Bar AND create a new Chassis ground as well.

Note: the 6ga or 8ga wires will be adequate as long as you are simply running the original 12v devices inside the coach. Once you decide to install an Inverter, you will need to increase the size of your Chassis ground wire to match the size of the cables feeding the Inverter.

[Jimander1]

I discharged the battery and the WFCO 55 amp CC output was 35A @ 3%SOC. I contacted WFCO to see why it is not closer to 55A, and they sent a checklist of items to further my inquiry. They recommend I have a resettable circuit breaker or auto-reset fuse within 3 ft of the battery, and want to know the value. Should I get add a 50A or 60A or other?

[Second Chance]

I discharged the battery and the WFCO 55 amp CC output was 35A @ 3%SOC. I contacted WFCO to see why it is not closer to 55A, and they sent a checklist of items to further my inquiry. They recommend I have a resettable circuit breaker or auto-reset fuse within 3 ft of the battery, and want to know the value. Should I get add a 50A or 60A or other?

WFCO does not have the best reputation on the planet. As part of their electrical upgrades, many on the forum have replaced the WFCO converter/chargers with with something like the Progressive Dynamics.

Rob

PS: if you completely discharge a LiFePO4 battery, there is a "trick" to getting it to "wake up" and take a charge again. You may want to Google that.

[Jimander1]

I did the same when we had our 22MLE. Definitely do not run the wire to the front. Run it through the rear of the dinette and that will put you 12" from the power panel/converter/charger and buss bars under the pantry cabinet. There's lots of room behind the power panel too. If you removed the board from the rear under dinette section and do some re-framing you could have a great space for an inverter, additional batteries, or whatever.

Now, when you connect the new wires from the power panel to your battery, leave those original wires to the tongue also connected. You'll need those for the power supply to the tongue jack. Snip off the connectors that were connected to the battery up front, or you can use them to power pegs that you can mount up front for an additional 12V power supply for accessories such as a portable air compressor. Have fun!

I connected the Positive to a to a 50A Short Stop circuit breaker (recommended by WFCO,) then connected the breaker to a (+) terminal on the DC distribution panel, right under where the charge controller connects. I probably bypassed the battery switch in the pass thru, because it no longer works. I contacted Grand Design, and their policy is not to provide schematics or electrical assistance. The original tongue battery location connected to a resettable breaker near the tongue. The resettable breaker likely connected to the battery switch, which then toggled DC to the DC fused items in the circuit panel box. To use the battery switch function, should I replace the short (+) terminal connection to the DC panel (under the charge controller terminal) with a (+) battery terminal wire to the pass thru switch? That would provide unswitched DC back to the jack, brake switch, tire minder...and toggle the DC circuits and engage the charger when battery switch is on.

[Riverbug]

I connected the Positive to a to a 50A Short Stop circuit breaker (recommended by WFCO,) then connected the breaker to a (+) terminal on the DC distribution panel, right under where the charge controller connects. I probably bypassed the battery switch in the pass thru, because it no longer works. I contacted Grand Design, and their policy is not to provide schematics or electrical assistance. The original tongue battery location connected to a resettable breaker near the tongue. The resettable breaker likely connected to the battery switch, which then toggled DC to the DC fused items in the circuit panel box. To use the battery switch function, should I replace the short (+) terminal connection to the DC panel (under the charge controller terminal) with a (+) battery terminal wire to the pass thru switch? That would provide unswitched DC back to the jack, brake switch, tire minder...and toggle the DC circuits and engage the charger when battery switch is on.

I ignored the OEM cutoff switch (just leave it in the on position), and I added a new cutoff switch at the new battery location so that it is a true cutoff switch which cuts 12V entirely when off. I don't have a good picture of that anymore but found one for reference in case it is helpful. I used a marine style switch off amazon. This of course goes in-line on the positive cable coming off the battery. Does that help?

[SolarPoweredRV]

I ignored the OEM cutoff switch (just leave it in the on position), and I added a new cutoff switch at the new battery location so that it is a true cutoff switch which cuts 12V entirely when off. I don't have a good picture of that anymore but found one for reference in case it is helpful. I used a marine style switch off amazon. This of course goes in-line on the positive cable coming off the battery. Does that help?

I agree with adding a "True" Cut-Off switch, in-line, on the positive battery cable.

I prefer to use the Blue-Sea battery switches however...

Amazon.com/Blue-Sea-Systems-Battery-Switch