House Battery Swap For Lithium

Joined
Jan 11, 2025
Posts
2
Location
Fort Collins
Hey everybody, me and my husband recently purchased a 2015 Thor Tuscany 45AT and read up that lithium batteries might be a better way to go for our coach. I was wondering if anybody has done this and if so is it as easy as just swapping the batteries or do we have to upgrade our equipment as well? Any help would be greatly appreciated.
 
There are dozens of people on this Forum that have upgraded to LFP (LiFePO4) batteries, probably no two installations are the same.

With the current price of LFP batteries they are cheaper than most AGM and even a lot of Flooded Lead Acid (FLA) batteries, so it definitely a smart choice when changing out the house batteries. And remember, 100 AH of a 100 AH rated LFP battery is usable as opposed to 50 AH of a 100 AH rated lead acid battery.

Your converter/charger will take a very long time to fully charge LFP batteries (if at all) and when it does, and goes into float mode, the LFP batteries will slowly drain to about a 60 to 70 % State Of Charge (SOC). Many people do the LFP upgrade and then just buy a separate lithium compatible charger to top them off when needed until they are ready to upgrade to a lithium compatible converter charger.

The other charging source of the alternator is also something to look at. Large LFP battery banks can overload the alternator and cause it to fail early due to overheating. That can be mitigated with a DC-DC converter or a LI225 BIM. Something to think about.

So that's a quick primer on a LFP upgrade. Go from there and do some research and come back and ask questions as you need to.
 
There are dozens of people on this Forum that have upgraded to LFP (LiFePO4) batteries, probably no two installations are the same.

With the current price of LFP batteries they are cheaper than most AGM and even a lot of Flooded Lead Acid (FLA) batteries, so it definitely a smart choice when changing out the house batteries. And remember, 100 AH of a 100 AH rated LFP battery is usable as opposed to 50 AH of a 100 AH rated lead acid battery.

Your converter/charger will take a very long time to fully charge LFP batteries (if at all) and when it does, and goes into float mode, the LFP batteries will slowly drain to about a 60 to 70 % State Of Charge (SOC). Many people do the LFP upgrade and then just buy a separate lithium compatible charger to top them off when needed until they are ready to upgrade to a lithium compatible converter charger.

The other charging source of the alternator is also something to look at. Large LFP battery banks can overload the alternator and cause it to fail early due to overheating. That can be mitigated with a DC-DC converter or a LI225 BIM. Something to think about.

So that's a quick primer on a LFP upgrade. Go from there and do some research and come back and ask questions as you need to.
Awesome post chief! Cheers from Keys!
 
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We have a 2015 Tuscany 4580 and we put lithium batteries in about three years ago. We were fortunate enough to have technicians from Britten Stop by and do the installation. They have worked great. Apparently they had to do a little adjustment to our solar to work with the lithium. Other than that. It only took a few hours and they were very helpful
 
Keep in mind that Lithium batteries don't work well in the cold weather.
If your battery compartment is located outside the heated space, get self-heating batteries.
Lithium batteries also last about 4 times as long as AGM or FLA, so in the long term are far less expensive.

I just installed lithium and use a 60A DC-DC charger to charge them off the alternator and they are also charged by solar. Make sure you get some kind of monitor so you can keep an eye on what they are doing. It's not necessary but they give lots of useful info. Some brands of batteries are smart and you can just plug the monitor in the battery, in my case I got a shunt that my monitor plugs into.
 
There are dozens of people on this Forum that have upgraded to LFP (LiFePO4) batteries, probably no two installations are the same.

With the current price of LFP batteries they are cheaper than most AGM and even a lot of Flooded Lead Acid (FLA) batteries, so it definitely a smart choice when changing out the house batteries. And remember, 100 AH of a 100 AH rated LFP battery is usable as opposed to 50 AH of a 100 AH rated lead acid battery.

Your converter/charger will take a very long time to fully charge LFP batteries (if at all) and when it does, and goes into float mode, the LFP batteries will slowly drain to about a 60 to 70 % State Of Charge (SOC). Many people do the LFP upgrade and then just buy a separate lithium compatible charger to top them off when needed until they are ready to upgrade to a lithium compatible converter charger.

The other charging source of the alternator is also something to look at. Large LFP battery banks can overload the alternator and cause it to fail early due to overheating. That can be mitigated with a DC-DC converter or a LI225 BIM. Something to think about.

So that's a quick primer on a LFP upgrade. Go from there and do some research and come back and ask questions as you need to.
Where is the DC-DC installed? Thank you.
 
Where is the DC-DC installed? Thank you.
Same Question.
Got a 2015 Thor Four Winds 26A Model FC26A-15 Class C.
Need to connect a DC-to-DC charger between a new LiFePo4 coach battery and the Ford E350’s chassis/starter battery.
Where can I get to the chassis battery 12V+ cable inside the RV, i.e. in the Power Center under the dinette seat?
 
Late response but may help others in the same situation. I had severe discharge issue with Costco interstate batteries. Every year I would buy two batteries. Some here rightfully suggested that I diagnose before dumping any more money. This was on sale and my RV came with the desired charge controller that had a setting to change to lithium charging, so I pulled the trigger before the tariff panic kicked in. All discharge issues disappeared. I can park the RV in front of my house for many days without shore power. A popular youtuber (Will Prowse?) crack opened this battery and found that it was well worth the price.

 
Since I power my whole house with LFP batteries amid the frequent power outages in FL, it was only natural that I converted our Thor Freedom Elite 26HE to LFP.
I never liked having the house battery below the entry steps, where it gets wet, dirty and and is exposed to the elements.
So, I opened up the rearward dinette bench and reorganized the wire mess there . . .🙄
There are 2 pairs of sturdy metal brackets to anchor the seat belts and those are perfect spots to secure 2 100A LFPs in between. Nice, dry and warm.
Since I am using Vatrer server rack batteries for my house, I went with the same company and bought 2x100A 12V batteries with integrated Bluetooth for monitoring.
I kicked the ancient battery under the entry steps out, installed a 50A fuse there instead and used the same cable, which runs to the electric department underneath the bench to connect to a Victron Orion DC-DC 50A charger.
Next step was to change the converter/charger inside the WFCO 8955 distribution center to a Lithium version.
(But not the one from WFCO itself, which $310, but an aftermarket version for 80 bucks)
Rigged the 2 batteries in parallel, installed the Victron 300A smart shunt between the negative battery side and the negative bus bar and all was running fine . . . So I thought.😉
When I had checked everything I remembered that we have a genset installed. Pressed the button . . . Dead.
Hhmm, now I remembered that there was a second red cable on the old LA battery, which I thought was for the emergency/jumper switch. I had it isolated with shrink wrap and zip tied to the battery tray.
That was actually the power cable to start the genset.
I just left it there. Too much effort to make a watertight connection underneath and run the cable to the batteries.
Since the genset sits almost exactly underneath the dinette bench, I drilled a half inch hole into the floor underneath the bench and ran a 4 gauge cable directly to the starter solenoid of the genset. Worked perfectly.
I measured the amperage during the startup process with a clamp meter and after an initial unreadable spike it settled to about 70 amps., which is just fine for the 4 gauge cable.
Costs:
$430 for the 2 batteries
$320 for the Orion DC-DC 50A charger
$85 for the Victron 300A shunt
$80 for the 8955 Li converter/charger
$65 for 2 ANL fuse boxes, some crimp lugs and cable.
 
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Did you move the 100 amp breaker to the new generator start line?
I did not see any 100A fuse/breaker.
I followed the genset starter cable underneath the chassis and it went straight from the "old" battery to the solenoid.
I was thinking about a resettable fuse, but did not know the amp draw, so I just installed it straight without any fuse.
But I can easily cut the 4-gauge cable inside the bench and install one.
Do you think it is necessary?
Since you answer a lot of electrical questions here I have a small problem with the whole setup.
When there are no lights, no radio and nothing else running I have about a 15W draw according to the shunt.
But when I go in the batteries via Bluetooth, there is nothing.
That explains also that the SOC according to the shunt is going down slowly, but the batteries are still showing no draw and 100% SOC.
 
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Since I power my whole house with LFP batteries amid the frequent power outages in FL, it was only natural that I converted our Thor Freedom Elite 26HE to LFP.
I never liked having the house battery below the entry steps, where it gets wet, dirty and and is exposed to the elements.
So, I opened up the rearward dinette bench and reorganized the wire mess there . . .🙄
There are 2 pairs of sturdy metal brackets to anchor the seat belts and those are perfect spots to secure 2 100A LFPs in between. Nice, dry and warm.
Since I am using Vatrer server rack batteries for my house, I went with the same company and bought 2x100A 12V batteries with integrated Bluetooth for monitoring.
I kicked the ancient battery under the entry steps out, installed a 50A fuse there instead and used the same cable, which runs to the electric department underneath the bench to connect to a Victron Orion DC-DC 50A charger.
Next step was to change the converter/charger inside the WFCO 8955 distribution center to a Lithium version.
(But not the one from WFCO itself, which $310, but an aftermarket version for 80 bucks)
Rigged the 2 batteries in parallel, installed the Victron 300A smart shunt between the negative battery side and the negative bus bar and all was running fine . . . So I thought.😉
When I had checked everything I remembered that we have a genset installed. Pressed the button . . . Dead.
Hhmm, now I remembered that there was a second red cable on the old LA battery, which I thought was for the emergency/jumper switch. I had it isolated with shrink wrap and zip tied to the battery tray.
That was actually the power cable to start the genset.
I just left it there. Too much effort to make a watertight connection underneath and run the cable to the batteries.
Since the genset sits almost exactly underneath the dinette bench, I drilled a half inch hole into the floor underneath the bench and ran a 4 gauge cable directly to the starter solenoid of the genset. Worked perfectly.
I measured the amperage during the startup process with a clamp meter and after an initial unreadable spike it settled to about 70 amps., which is just fine for the 4 gauge cable.
Costs:
$430 for the 2 batteries
$320 for the Orion DC-DC 50A charger
$85 for the Victron 300A shunt
$80 for the 8955 Li converter/charger
$65 for 2 ANL fuse boxes, some crimp lugs and cable.
Skip, any chance that you might have some pics of your install. Looking to to the exact same thing here in the next week or so. Also any additional suggestions of thing you would have done differently if doing over?
 
Skip, any chance that you might have some pics of your install. Looking to to the exact same thing here in the next week or so. Also any additional suggestions of thing you would have done differently if doing over?
Got pics of it, but we are on a trip til July 15th. And I don’t have access to my main computer at home right now.
I am happy to share what I have once I am home again.
 

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