Undersize charging wire, WFCO to batteries, Upgrading to lithium in 2019 T@B 400

jimcenname · May 2024

In my 2019 T@B400 (no solar) I just replaced the two original AGM Harris Batteries with a single Battle Born 100ah lithium. The original charger, 55 amp WFCO 8955PEC, isn't lithium compatible. Battle Born Rep offered a 55 amp Progressive Dynamics 4655V to convert the WFCO to Lithium capable. My problem was the factory wire between the WFCO and the AGMs is 8 gauge and runs 22 feet long behind cabinets and under the bathroom floor. Both Battle Born and nuCamp agreed that is undersized for that distance for a 55 amp charger. I don't know why it also isn't undersized for the existing AGM batteries. Though I know of no problem it caused in the 4 1/2 years I have lives in my T@B. Instead of running 22 feet of 4 gauge wire I bought a PD9345 "deck mounted" charger, installing it right next to the new lithium battery. Only 2 feet of cable required. Also I disabled the charging feature on the WFCO by removing a single power wire for the panel breaker. FYI, I also installed a shunt to monitor the lithium battery and an ANL fuse on the battery's hot wire. Progressive Dynamics said to run a dedicated ground wire from battery-negative to chassis-ground. The existing battery compartment vent hole provided a passage through the floor. Since Lithium doesn't require venting for gas I eliminated the battery encasement cover.

RMo · May 2024

Thanks for the overview. I’m considering something similar and have a few questions. How difficult was it to remove the black cover? Any tricks? What are the dimensions of the space that remains after you remove the cover? Any lessons learned that might be useful?

jimcenname · May 2024

I removed the lower third of the bed platform. Then unscrewed about 10 screws holding the cover in place. I lifted the cover on the outbound side, disconnected the battery cables and feed them through the hole on the side of the cover. Then the cover lifted off. The AGM batteries weigh about 60 lb each. I flipped them on their side and pushed them out the cargo access door. The roughly 11 X 8 inch space of one AGM battery was used for the new charger, shunt and fuse. I gained no space but lost about 90 pounds. I'll have to see how much the tongue weight changed.

RMo · May 2024

Did you use the original pos and neg leads from the battery, or replace them with larger gauge wires?

thanks,

jimcenname · May 2024

They were 4 gauge cables about 2 feet long. That's sufficient to handle the current from the charger, which is at the end of a 2-foot long 4 gauge cable. They connect at the existing distribution studs.

Binghi · January 21

Nice mod, @jimcenname - I’m upgrading my 2021 400 to lithium and thinking of doing something similar.

A few questions:

How come you used the PD 9345 instead of the PD 9360? Wouldn’t the 9360 charge the battery faster?

It looks like you put in an AC outlet to power the converter. Did you create a dedicated circuit for the outlet by running the outlet cable back to the power center and installing another circuit breaker? What gauge cable did you use?

Did you keep the OEM inverter?

Thanks!

SLJ · January 22

When I installed my lithium batteries I also put in a Victron Smart Charger for charging them when on shore power. When on shore power I let my non-lithium WFCO (2021) supply DC and just shut off my batteries. If they need charging I switch on the Victron and let them charge. When I unplug from shore power I just turn them back on. I trust the Victron charger way more than any WFCO.

tphaggerty · January 25

I have a 2018 400 that looks very similar to your pictures with the battery located under the bed. I'm having trouble understanding the "22 ft" wire run. In my Tab, the wire from the WFCO (now upgraded to a Progressive Dynamics) runs from the converter directly under the bed (in a subfloor) to that back compartment, basically the width of the trailer, so maybe 10 feet.

I have 3 Renogy 100ah Lithium batteries in that space now. While I too have concerns about that wire being undersized, it doesn't seem to be an issue so far. I have felt the charge wire while charging at 55 amps and it hasn't been hot at all. I plan to install a larger gauge wire in the spring, but not sure where the 22 ft measurement is from/to.

RMo · January 25

I'm having trouble understanding the "22 ft" wire run.

When choosing an appropriate wire gauge you’ll want to consider the entire circuit length - negative from the battery and positive back to the battery. Given this is a 22 foot run it would mean 11 feet each way.

jimcenname · January 25

My WFCO is under the dining bench seat by the door, the cable from the WFCO's 55 amp non lithium charger goes across the trailer to the space under the other bench seat then to the rear via the spacer under the shower and Alde compartment then back to the other side of the trailer to the battery. 22 feet of wire. That's a long run for 12 volts/55amps. Using a 45 amp charger reduces the gage wire requirement. I rarely boondock (at most overnight at a Cracker Barrel) so I don't do a lot of demanding charging. If the the battery is at 60 percent state of charge it takes about 30-45 minutes to get it back to 100 percent with the 45 amp charger. BTW the battery/charger area is not well vented so when doing that kind of charging it gets to 95-100 degrees briefly. I may install a vent and fan. For comparison, my Alde compartment is ~105 degrees right now, 50 degrees outside.

jimcenname · January 25

Binghi said:

Nice mod, @jimcenname - I’m upgrading my 2021 400 to lithium and thinking of doing something similar.

A few questions:

How come you use d the PD 9345 instead of the PD 9360? Wouldn’t the 9360 charge the battery faster?

It looks like you put in an AC outlet to power the converter. Did you create a dedicated circuit for the outlet by running the outlet cable back to th usinge power center and installing another circuit breaker? What gauge cable did you use?

Did you keep the OEM inverter?

Thanks!

Using Romex I did install an outlet by the new charger. I tapped into the circuit that powers the outlet by the kitchen sink and runs to the foot of the bed, so I don't use my Keurig on that outlet when I have to charge a lot. I don't have an inverter. I don't have solar. I don't boondock. I rarely deep dishcharge and recharge. I don't need the extra charging speed of a 60 amp charger and didn't want to deal with the bigger-yet gage cables.

Binghi · January 25

Got it, thanks a lot.

qhumberd · July 14

jimcenname said:

I removed the lower third of the bed platform. Then unscrewed about 10 screws holding the cover in place. I lifted the cover on the outbound side, disconnected the battery cables and feed them through the hole on the side of the cover. Then the cover lifted off. The AGM batteries weigh about 60 lb each. I flipped them on their side and pushed them out the cargo access door. The roughly 11 X 8 inch space of one AGM battery was used for the new charger, shunt and fuse. I gained no space but lost about 90 pounds. I'll have to see how much the tongue weight changed.

Thanks for the inspiration @jimcenname! I just checked my 2019 AGMs in my 400 and they are definitely not able to keep up with even an overnight on the road. After a lot of scanning threads I finally decided on the LiTime since the sale was too good to pass up.

LiTime 12V 230Ah Plus Deep Cycle LiFePO4 Battery with Low-Temp Protection. This single 12 V is small enough to fit the space of the Harris AGMS with a little to spare. I was just worried how to get them out and the idea of going out the cargo door is great.

I also have no solar on board and no inverter, just a solar charging port on the driver side and a shunt next to the distribution box. I was wondering about the need to remove the passenger third of the bed platform. Did you remove the hinges to do that?

And did your require more cables for your new battery?

Thanks

My cover looks like this:

Image: https://us.v-cdn.net/5021717/uploads/editor/it/ay0kuhsytcr5.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/5y/oii7mkolie1p.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/s3/qhvacp4n91ho.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/zp/g1eole1o9mwk.jpg

jimcenname · July 14

I learned that when nuCamp did a major Alde repair the technician did not secure the bed panels well. I removed all of the screws, realigned the panels and refastened them while I was doing the battery install. I did add new cables for the new charger and was able to reuse all of the original cables. Don't have the ability to make a cable so I bought premade cables that were sometimes oversize or longer than necessary.

qhumberd · July 24

@jimcenname many thanks for the nudge to change out the batteries in my 2019 400. Like you I had no solar but a solar port on the driver side, and no inverter.

The battery cover on the Harris batteries was keeping me from starting but when I did, I only found 4 screws securing the top of the cover, and I only had to remove one bed panel along the passenger wall to get access.

The LiTime 230 amp hour with low temp protection was a slightly smaller footprint, and allowed room for the small 10 am Lithium charger on the cargo door side.

Image: https://us.v-cdn.net/5021717/uploads/editor/bu/uksnhmqmypdi.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/6h/8qywqzzzsygi.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/sn/bavfvfocmlyr.jpg

As you mentioned, the cover was able to angle back and then tilt to the middle of the trailer to get access to the battery posts. The existing wires (White is Neg and Red is Pos) were plenty long enough and basically required no wiring changes at all. Just hooked up the lithium and done. I had an inexpensive shunt that turned on and I reset to the new 230 amp hour level and it all worked!

Now as I understand the original WFCO converter will not bring the lithium to 100%, I used the space next to the cargo door for the new small charger, which in my model can plug into the AC plug (for the frig) that is on the wall just inside the cargo door. It is a 20 amp circuit so I can just swap plugs when I need to top off the battery or can use a splitter. Again, no rewiring so very relieved on that count.

Hope these pictures can help others as needed, though our 400 is now over 5 years old and likely does not resemble the build of the new units.

Thanks again to all on the forum

jimcenname · July 25

Your installation looks better than mine. Since I installed a 45 amp charger I had to get some big cables, which was my challenge. My power source for the charger was the AC outlet nearby at the foot of the bed.

qhumberd · July 25

Thanks and my final question is if you isolated your current WFCO converter from the new battery, and if so, how?
Since we rarely boondock, like you, I felt my need for a charger for the lithium would be infrequent. And I had the small frig which has a 20 amp AC plug right inside the cargo door I use for the new charger. I think I can rely on the small charger to keep my battery topped off from time to time, but I am worried about leaving the WFCO non lithium connected all the time. What did you do?

jimcenname · July 25

Within the WFCO I disconnected the internal 55 amp charger by removing the input power wire. The WFCO still functions in its power distribution role. The new 45 amp external charger does all the work charging. Battleborn tech walked me through this. Since an RV consumes 12 volt power even when connected to shore power and the charger works to keep the battery topped off.

qhumberd · July 25

Got it, thanks. I must have pulled the wrong wire on my converter as it cut the trailer circuits as well. For me just keeping the battery disconnect switched on while on she power will be the easiest

Yoshi_TAB · July 25

Hi,

Not sure if this is helpful of a typical connection. The AC power is on the left and the DC wires are on right.

The white and black wires will disconnect AC from the converter. Black is connected to a breaker.

Image: https://us.v-cdn.net/5021717/uploads/editor/th/b87clnkph01s.jpg

qhumberd · July 25

Yoshi_TAB said:

Hi,

Not sure if this is helpful of a typical connection. The AC power is on the left and the DC wires are on right.

The white and black wires will disconnect AC from the converter. Black is connected to a breaker.

So this is the diagram I used when attempting to isolate the WFCO from the battery at the board but retain the rest of the functions. The diagram shows a White neg in a dual connector (the other goes to the Main Board below. The Red wire is on a similar dual connector on the lower L of the board, though mine has a second Red on the L side of that connector. Not sure where that one goes cause the other large wire is Pink in the middle single connector and that one clearly goes to main board below.

I pulled both the White and Red with all power off, thinking these only went to the battery. Turned shore power on and none of the 12 V circuits worked. Same with pulling only Red or only White. So not sure where I messed up.

Bayliss · July 25

@qhumberd, I installed a Progressive Dynamics PD4135 power center in my 2019 T@B 320 S Boondock Lite, but it sounds like your PD9345 has similar wiring. Take a look at the manufacturer's instructions for your specific application. Mine provides the following information regarding the two red wires. I capped off and taped the second red wire (labeled "002") since I did not need it:

12V DC WIRING: Only the red wire in position 001 goes to the battery. The second red wire (002) is reserved for a higher load 30-amp max branch DC circuit. (WARNING: do not use 002 for connection to the battery.) The black wires (003-007) are for 20-amp max branch DC circuits.

Your DC items go to the individual numbered wires, corresponding to fuses. (+ side.)

Your return side (white neutral wire) of DC items go to a ground bar outside of the [PD4135], which in turn are connected to the DC-side of the system and battery. Or, sometimes, the chassis is the DC return and the lights, etc. are connected through the chassis.

The black wires (marked 003-007) and corresponding fuse slots (F3 - F7) are for 20-amp max branch DC circuits.

The red wires and corresponding fuse positions are rated for 30 amps max - marked 001 and 002.

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Undersize charging wire, WFCO to batteries, Upgrading to lithium in 2019 T@B 400

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2019 T@B400 Boondock Lite "Todd"

2019 T@B400 Boondock Lite "Todd"

2019 T@B400 Boondock Lite "Todd"

2019 T@B400 Boondock Lite "Todd"

2019 T@B400 Boondock Lite "Todd"