Adding Lithium batteries to a 2021 Xls 22 RBE

[J & J Bumblebee]

Hi,

The trailer has solar wiring but no controllers or panels. I'm going to add solar to our trailer very slowly, but first, I'm going to swap out the single lead acid battery with two LiTime 12V 100Ah Group 24 LiFePO4 Lithium Batteries, Built-In 100A BMS, 1280Wh Energy.

My trailer doesn't have a controller that will work with Lithium batteries ( WFCO WF-8735P-GE ) I'm going to install a similar model WFCO WF-8735-AD to take care of that.

I've noticed most installs are under the bed or inside the front storage area. What is wrong with installing them where the OEM battery is in front of the trailer? Would it better to install them under the bed inside the trailer with a different size battery?

I've ordered the 'Mobile Solar Power Made Easy 'book and will be reading that cover to cover when it gets here. I just wanted to run this by you here to help me get started.


Thanks,

John

[TucsonJim]

Hi John,

I ran three LiFePO4 batteries on the tongue of my trailer for several years, and it worked fine. The primary concern is temperature exposure and theft. Most LiFePO4 batteries can be damaged if you try to charge them below 32°F. Since I live in Arizona, we rarely ever see that temperature. And if we did, I'd made sure they weren't being charged. Even if you can't charge them below freezing, you can typically still discharge them down to -4°F. I you put the batteries inside, you shouldn't be subjecting them to temperature extremes.

Jim

[howson]

I've noticed most installs are under the bed or inside the front storage area. What is wrong with installing them where the OEM battery is in front of the trailer? Would it better to install them under the bed inside the trailer with a different size battery?

Another reason some install inside is they install a higher-capacity charger or a combination inverter/charger. To keep the high-amperage wires between the battery bank and these components as short as possible they install everything in one location. In a small TT a common location is under the bed.

Nothing "wrong" with the plan to install the newer WFCO in place of the OEM model knowing that the new WFCO won't leverage all of the new battery's higher charge rate capability. (In other words, it's not important that the battery charges as fast as it's capable of charging.)

I've ordered the 'Mobile Solar Power Made Easy 'book and will be reading that cover to cover when it gets here. I just wanted to run this by you here to help me get started.

[J & J Bumblebee]

Thank you both.

I know going with solar can get very expensive, and for now, I'm taking baby steps. I'll continue with my plan and as I gain more knowledge I'll expand the system.

[StephenO]

I've noticed most installs are under the bed or inside the front storage area. What is wrong with installing them where the OEM battery is in front of the trailer? Would it better to install them under the bed inside the trailer with a different size battery?

You've been given good info here, I would add one thing to consider. Start with tracing out all the OEM wiring from the existing battery hookup point on the tongue, all the way back to the power distribution unit (PDU) and make up a 'current state' wiring diagram. Include everything you can there, like the existing battery disconnect, power jack, truck 7way cord, battery wiring, etc. Make sure to document the wire gauge and any terminal connection sizes (it makes it easier to have that info handy if you plan on crimping new cables while upgrading)

Then do up an 'end state' diagram of what you want to have in the end, and this should give you an upgrade path for the connections 'northbound' of the PDU. This is assuming you don't want to change any of the wiring after the PDU, but if you do, add it to your diagrams.

I did this for our trailer, and it helped solidify my plan to move the batteries inside the front storage area. Long story short, it showed to me that I had a single wire from the front tongue, to the battery disconnect switch inside the front storage area, which is used to bring in 12v after the self resetting breaker. My plan is to reverse the flow on that wire and use it to bring power out to where the batteries were, but I do need to reconfigure the connections at the self resetting too. Also on the other side of that disconnect switch in the front bay, is the PDU, so it'll fairly easy to reconfigure that, and again bring the batteries inside the front storage.

I am sure I am not explaining this super clearly, but this idea has been discussed on the forum before, so let me know if you have any questions.

My trailer doesn't have a controller that will work with Lithium batteries ( WFCO WF-8735P-GE ) I'm going to install a similar model WFCO WF-8735-AD to take care of that.

Just make sure the wiring between the converter and battery is heavy enough to accept any higher charging current. Again, doing up a diagram should help capture this.

Enjoy the upgrade, I know my wallet is not thanking me for all this, but it's a fun process!

[BobinICT]

Hi,

The trailer has solar wiring but no controllers or panels. I'm going to add solar to our trailer very slowly, but first, I'm going to swap out the single lead acid battery with two LiTime 12V 100Ah Group 24 LiFePO4 Lithium Batteries, Built-In 100A BMS, 1280Wh Energy.

My trailer doesn't have a controller that will work with Lithium batteries ( WFCO WF-8735P-GE ) I'm going to install a similar model WFCO WF-8735-AD to take care of that.

I've noticed most installs are under the bed or inside the front storage area. What is wrong with installing them where the OEM battery is in front of the trailer? Would it better to install them under the bed inside the trailer with a different size battery?

I've ordered the 'Mobile Solar Power Made Easy 'book and will be reading that cover to cover when it gets here. I just wanted to run this by you here to help me get started.


Thanks,

John

John, I recommend holding off on the WFCO WF-8735-AD. Later today I'm going post my experiences with that unit, that is no longer in my rig. I believe I have found a good replacement at a cheaper price and will make my observations shortly.

[J & J Bumblebee]

You've been given good info here, I would add one thing to consider. Start with tracing out all the OEM wiring from the existing battery hookup point on the tongue, all the way back to the power distribution unit (PDU) and make up a 'current state' wiring diagram. Include everything you can there, like the existing battery disconnect, power jack, truck 7way cord, battery wiring, etc. Make sure to document the wire gauge and any terminal connection sizes (it makes it easier to have that info handy if you plan on crimping new cables while upgrading)

Then do up an 'end state' diagram of what you want to have in the end, and this should give you an upgrade path for the connections 'northbound' of the PDU. This is assuming you don't want to change any of the wiring after the PDU, but if you do, add it to your diagrams.

I did this for our trailer, and it helped solidify my plan to move the batteries inside the front storage area. Long story short, it showed to me that I had a single wire from the front tongue, to the battery disconnect switch inside the front storage area, which is used to bring in 12v after the self resetting breaker. My plan is to reverse the flow on that wire and use it to bring power out to where the batteries were, but I do need to reconfigure the connections at the self resetting too. Also on the other side of that disconnect switch in the front bay, is the PDU, so it'll fairly easy to reconfigure that, and again bring the batteries inside the front storage.

I am sure I am not explaining this super clearly, but this idea has been discussed on the forum before, so let me know if you have any questions.




Just make sure the wiring between the converter and battery is heavy enough to accept any higher charging current. Again, doing up a diagram should help capture this.

Enjoy the upgrade, I know my wallet is not thanking me for all this, but it's a fun process!

Thanks! I have to wait until all this lovely rain we're having subsides before crawling under the trailer to map things out. I have jumped into this quickly. More research and thought needs to go into it.

[J & J Bumblebee]

John, I recommend holding off on the WFCO WF-8735-AD. Later today I'm going post my experiences with that unit, that is no longer in my rig. I believe I have found a good replacement at a cheaper price and will make my observations shortly.

Thank you, I will do that. It's arriving from Amazon on Thursday, and it's easy to return.

[J & J Bumblebee]

I just wanted to update my little ordeal with the WFCO converter.

I'm currently waiting on a Siemens QT 30/15 Breaker from the Orange Big Box store. It was supposed to be delivered yesterday, but they failed. In hindsight, I could have swapped out the buss bar from the other converter and used the existing breakers. Also, I could have gotten a different set of QT breakers and installed those, but I transferred the labels for the circuits from the old to the new and didn't want to relabel them.

I'm funny like that.

I have swapped out the Deep cycle Interstate battery with the two LiTime 100AH batteries I purchased. I'm going to charge one when I get the power restored and then the other. After that, they recommend hooking them up so they can balance out. Then I can energize everything and go from there.

I've learned a couple of things from this little episode and can't wait to get the trailer out camping.

John

[Jlawles2]

you can take the batteries and charge them using a standard charger. they will not be at 100%, but this will get you ahead of the game by a day or so.

Also if you check their voltages and they are within 0.25 volts of each other, you can parallel them and charge them as a pair. Hook one charging lead to the positive on one battery and the negative charging lead to the negative of the other battery. This helps ensure the batteries "share" the input.

[J & J Bumblebee]

you can take the batteries and charge them using a standard charger. they will not be at 100%, but this will get you ahead of the game by a day or so.

Also if you check their voltages and they are within 0.25 volts of each other, you can parallel them and charge them as a pair. Hook one charging lead to the positive on one battery and the negative charging lead to the negative of the other battery. This helps ensure the batteries "share" the input.

I was wondering if I could do that. I don't want to screw them up. Thanks!

[acoleman43]

I was wondering if I could do that. I don't want to screw them up. Thanks!

Before I installed my batteries that's exactly what I did. Obviously I have a VIctron IP67 charger . Charging batteries before installing them is called top charging. You want to make sure all batteries in your battery bank are at the same SOC before connecting them for best results.

[reubenray]

I am following this thread hoping for more information for my battery upgrade. I am very illiterate when it comes to electricity.

[howson]

I am following this thread hoping for more information for my battery upgrade. I am very illiterate when it comes to electricity.

I highly recommend investing $15 to get (and read/study!) Mike Sokol's book. Master the contents and you'll be well on your way to understanding your rig's electrical setup. https://www.amazon.com/No-Shock-Zone.../dp/0990527913

[J & J Bumblebee]

Well.......I did take a voltage reading on each battery. Surprisingly ( to me ), they were both at 13.11 V. So, I connected them in parallel so they could bond together and left them alone.