Lithium battery install for 2021 T@b 320 S-BD

DanSees · November 2022

First thing, I would like to thank everyone on this forum that was so helpful in thier replies or previous posts on installing lithium batteries in the T@b. Your help goes beyond any words I could write here. So a big THANK YOU!!!

As the title suggests we own a 2021 T@b 320S BD. We bought it second hand & it had been in service for 5 months by a young couple in Winston Salem NC who used it while they traveled out west for about 3 months. When they bought it they had a 125amp AGM battery installed and the WFCO charger/converter for lithium batteries was not yet being installed by nuCamp. Being the Boondock model it came equiped with the 105watt solar panel on the roof with a Victron 75-15 controller/charger & a Victron Smart BMV 712 installed. The battery & BMV 712 were installed in the front tub on the tongue.

I removed the battery & the BMV 712 from the tub & installed the new lithium batteries in the space in front of the Air 8 under the bed on the passenger side.

I installed 2 Lion Energy 1300 105 amp batteries in parralle. I also installed the BMV shunt under a 2x4 by the batteries that is used for the bed frame. I installed the meter for the V 712 on the wall above the Alde & Air 8 panels.

I installed a Victron DC-DC 12/12/30amp charger in the compartment in front of the Air 8 & batteries. For this charger I ran 6awg wire in to the camper at the original location of the 10awg wires for the battery to feed the converter. This was no easy task. I tied a string to the 10awg wires & pulled the original wire out leaving the string in place then I attached the string to the 6awg wire & pulled it through the original routing. This worked for 1 wire but not both. The diameter difference between the 10awg & 6awg wire was signicant enough to not allow both of these wires through the retainer under the shower tub. So I was able to run the 2nd wire under the shower tub which has a false floor to allow for plunbing of the shower drain & the alde water & transfer fluid lines. I then ran these 2 wires Positive & Common to an Anderson type connector to attach to a second coupler on the rear bumper of my truck, then routed to the battery. Each end of the positive wire incorporates a 60 amp circuit breaker as recommended by Victron at each battery.

I up graded the WFCO 8735 converter charger to a WFCO 8735 AD. The AD is for auto detect of which ever type battery you have, be it Lead Acid, AGM or Lithium. After installing this new converter I tried to get it to recognize the lithium batteries & that is when I found a lot of people having issues doing this procedure. I think I would have just bought a charger for lithium batteries had I noticed this before hand. Initially I did as a tech from WFCO told me to do. Disconnect the solar charger. Drain 1 battery until it's bmc turned it off, recharge to 100% by connecting 120 AC power & it should recognize the lithium This DID NOT WORK. Instead I youtubed it & found a video by WFCO that showed a little different sequence. Once the battery is drained to close to 10% remaining. turn on 120 AC then turn on battery cutoff. apply a load on the DC system. When the converter charger gives a red light which indicates it is charging. Turn off the 120AC wait 30 seconds or until the red light goes out then turn on the 120 ac again, the green light should then change to blue with in 2 minutes . This indicates the converter/ charger is in lithium mode. This worked for me. I think the biggest part of this procedure is having a dc load on the battery & doing the swithing of power when the bateery is low on power & needs a charge. After the converter recongized the lithium, I shut it off & connected the second battery, the solar controller & the DC/DC charger. The converter continued to stay in the lithium mode after I turned everything back on.

Then next I connected the tow vehicle up to the camper with the 7 pin plug & the Anderson connector & procedded to set all the parameters through the Victron

The first pic shows the DC-DC charger installed. This unit can get very hot & should be installed close to the batteries but with plenty of ventilation. I also fabricated a mount for it so it was sitting against eh wood paneling in the compartment.

The second pic shows the wiring & WFCO converter charger in the left side wheel well.

The 3rd pic is the BMV 712 gauge.

The 4th picture is the batteries & BMV 712 shunt installed . the shunt is on the far left hand side of the pic mounted under the 2x4.

App.

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Image: https://us.v-cdn.net/5021717/uploads/editor/dz/1t4lph31zpyr.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/qi/ek3zx95afnu0.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/e3/ivaytge5k3qh.jpg

Denny16 · November 2022

Your install came out very nice. It was interesting to read how you got the WFCO converter to auto detect the lithium battery. Have fun and stay safe.
Cheers

DanSees · November 2022

Thanks Denny16

Maple_Geek · November 2022

Great job! I recently bought a second lithium battery and I'm also contemplating moving them to the passenger side inside area. Since my TAB is already in storage for winter, I don't know if they will fit beside the Air8 like you did or under the passenger seat. I would prefer what you did since it leaves room for storage under the passenger seat. Thanks for sharing!

DanSees · November 2022

Maple_Geek said:

Great job! I recently bought a second lithium battery and I'm also contemplating moving them to the passenger side inside area. Since my TAB is already in storage for winter, I don't know if they will fit beside the Air8 like you did or under the passenger seat. I would prefer what you did since it leaves room for storage under the passenger seat. Thanks for sharing!

I watched Genn Grover's youtube about the battery install, The tech that installed hers made a box for the batteries. I used the same batteries, Lion Energy1300. I thought there should be some air movement around the batteries. I'm not sure that this is actually required but it can't hurt. So I installed 1x1 angle iron onto the floor with a 1/8" gap. To allow the strap to slide. I then added 1/4" rubber under the batteries to also allow the strap to move & then just snugged up the strap to hold the batteries in place. In my T@b the Air 8 is held in with straps so I feel the strap will hold the batteries along with the angle iron so they don't slide.

Maple_Geek · November 2022

Other than the 6awg wire for your DC-DC charger, did you have to do a lot of wire manipulation/addition?

My camper is in storage so I'm going by memory and information I've found on this site but other than feeding the new battery location and making sure 12V still gets to the front tub for the emergency break disconnect switch, there doesn't seem to be much to it. I could be wrong. Did you move the cutoff switch from inside the tub to a spot close to your batteries or is that a new one you bought?

DanSees · November 2022

Maple_Geek said:

Other than the 6awg wire for your DC-DC charger, did you have to do a lot of wire manipulation/addition?

My camper is in storage so I'm going by memory and information I've found on this site but other than feeding the new battery location and making sure 12V still gets to the front tub for the emergency break disconnect switch, there doesn't seem to be much to it. I could be wrong. Did you move the cutoff switch from inside the tub to a spot close to your batteries or is that a new one you bought?

Other than the 6awg, the other wiring I did was to cut & removed the dc side of the converter & splice in the new converter, removed the 120ac from the converter & reattach the new converter with the original wires & circuit breakers. T ake a picture or write down the location of each breaker & witch wire feeds it. All the grounds & commons go to the same bus bar respectfully. I left the wires from the converter to the junction box on the tongue. There were 2 sets of 10awg from the front of the tongue to the inside. One set which I replaced with the 6awg & the other went to the solar charger.

I took the wire I removed from the tongue & used it for the solar charger to battery + & - & used the original solar wire as the feed to the tongue junction box. One thing to note, the solar charger requires a high strand count for the wire from the charger to the battery. I used the wire I removed that i replaced with the 6awg. The other wires I used were stranded awg wire but not a high amount of strands. I purchased my wire from Lowes Home Center.

I used the original battery cutoff , I just moved it to be close to the batteries. I didn't see any reason to leave it on the tongue. I istalled new screws with sealant on them in the holes left by the cutoff switch.

I also had to run the cable for the Victron 712 down through the wall & over to the shunt. It was plenty long enough. I used a plumb bob & dropped it down the inside of the wall and attached the wire to the string on the plumb bob to feed it through the wall.

Hope this helps.

Maple_Geek · November 2022

Thanks very much. The converter in my 2022 TAB has a switch for lithium so I'm not planning to replace it. In fact I had one lithium battery most of the 2022 summer and that worked well.

I will have to run a new wire from the roof Victron solar controller to the battery but I'm not planning to remove the extra 10awg wire to the tub I will be left with it seems. I may use it for the side tub SAE port for my external solar panel...until I decide to punch a hole on the passenger side of the camper to get the solar controller closer to the batteries.

I'm also not planning on installing a DC-DC charger like you did. I won't get as much charging capacity as you over the existing 10awg wire when I drive but that hasn't been an issue for me...yet.

DanSees · November 2022

Maple_Geek said:

Thanks very much. The converter that was in my 2022 TAB has a switch for lithium so I'm not planning to replace it. In fact I had one lithium battery most of the 2022 summer and that worked well.

I will have to run a new wire from the roof Victron solar controller to the battery but I'm not planning to remove the extra 10awg wire to the tub I will be left with it seems. I may use it for the side tub SAE port for my external solar panel...until I decide to punch a hole on the driver side of the camper to get the solar controller closer to the batteries.

I'm also not planning on installing a DC-DC charger like you did. I won't get as much charging capacity as you over the existing 10awg wire when I drive but that hasn't been an issue for me...yet.

Sounds good, That converter/charger is probably a better solution than the one now offered with auto detect, just use the switch!!! I've read many complaintson the auto detect, but mine is still holding on lithium.

I did read in someones post here on the forum that they purchased the high strand count wire from a marine supply store. In my area I don't have much choice locally even though there are several boat dealers here.

One of the things with the DC-DC charger is to prevent back feed to the tow vehicle. This in turn could do damage to your battery or alternator. If you were to use a lesser amperage dc-dc charger like the 12/12/18 or 12/12/20 you could use the original 10awg wired through the 7 pin connector. Although many people have done as you are doing & have not had any issues. I am a retired aircraft mechanic & I almost always go overboard with redunant or saftey systems. Just my 40+ years of thinking. Can't pull over at 30,000 ft!!!

Maple_Geek · November 2022

I also checked and my batteries are the same size as yours so that gives me hope that I will be able to install them beside the Air8 like you did. Looking forward to the spring!

DanSees · November 2022

We are still using ours, planning a trip in Dec to FL. Going to test this new setup.

Maple_Geek · November 2022

Lucky you!!! Where are you located? Snow will be here anytime now in my area. We've had an unusually warm fall so far but it's coming to an end. Snow and cold don't worry me much but road salt is not something I want the TAB to be exposed to.

DanSees · November 2022

We are in Southport NC , which is on the border of NC & SC. We might get a dusting of snow here once a year, But it shuts the town down. I grew up in Pittsburgh PA so I'm no stranger to snow & salt.

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Lithium battery install for 2021 T@b 320 S-BD

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