Can I upgrade to Lithium on my 2025 Spirit 26T?

[Tim.D]

Have a 2025 Spirit 26t and cannot find anywhere if I can change to Lithium on the house batteries. Does anybody know if the charge controller is capable of it?

 

[Bnystrom]

Locate your converter or inverter/charger, and get the brand and model number. Go to the manufacturer's website and download the owner's manual and/or spec sheet for it. If you still have questions call the manufacturer and speak with their tech support.

Even if your hardware doesn't have a setting for LiFePO batteries, it will still charge them to 85% capacity or more. You can install 200Ah of LiFePO batteries without adding any additional hardware. If you go higher than that, it's best to install a DC-DC charger to protect the alternator. If you think you may want to go higher than 200Ah in the future, install a single 200Ah battery now, which will leave you with room to add another down the road. I recommend that you buy good quality batteries, from an established, reputable company, not low-end Amazon junk.

 

[Goodspike]

Have a 2025 Spirit 26t and cannot find anywhere if I can change to Lithium on the house batteries. Does anybody know if the charge controller is capable of it?

If the 120v converter is a WFCO automatic detect model (one that has a model number likely ending in "AD") it may not work that well at detecting the correct battery type. Not detecting the proper battery will impact the ability to fully charge, which over long periods of time can affect the cell balancing. It's not just a matter of the battery only charging to 85%. Also you should add a terminal fuse (or some other type of fuse) to a lithium battery--not needed for lead acid but it is needed for lithium.

I'd also add you should get a Victron shunt to monitor the state of charge of the battery. The shunts that are built into some of the batteries are not very good whereas the Victron units are top rate. You don't want to get to zero battery left because your battery's built in shunt it telling you that you still have 50% of battery left.

I'm not sure about this but you may need a DC to DC charger designed for lithium, but that may be less of an issue on a motorhome than with a trailer and two vehicle. If it were a trailer a tow vehicle you'd more likely need such a device.

 

[Bnystrom]

If the 120v converter is a WFCO automatic detect model (one that has a model number likely ending in "AD") it may not work that well at detecting the correct battery type. Not detecting the proper battery will impact the ability to fully charge, which over long periods of time can affect the cell balancing. It's not just a matter of the battery only charging to 85%.

Topping off the batteries to 100% can be easily accomplish with solar (if he has it and has a compatible charge controller) or with an inexpensive external charger. It should be done a handful of times per year. With proper monitoring, it's easy to tell if there is significant cell imbalance.

Also you should add a terminal fuse (or some other type of fuse) to a lithium battery--not needed for lead acid but it is needed for lithium.

The lead-acid batteries DO have a fuse, it's just not located on the terminal. It's typically mounted on the side of the battery box. ALL batteries should be fused, regardless of their chemistry.

I'd also add you should get a Victron shunt to monitor the state of charge of the battery. The shunts that are built into some of the batteries are not very good whereas the Victron units are top rate. You don't want to get to zero battery left because your battery's built in shunt it telling you that you still have 50% of battery left.

That's not a problem if you buy quality batteries, and you're grossly exaggerating the issue anyway. Yes, a Victron shunt is the "gold standard" and it certainly can't hurt to install one. However, the app for the SFK batteries I use displays cell voltages down to 1/100 of an amp, which eliminates the need for a shunt.

I'm not sure about this but you may need a DC to DC charger designed for lithium, but that may be less of an issue on a motorhome than with a trailer and two vehicle. If it were a trailer a tow vehicle you'd more likely need such a device.

Actually, it's the other way around. Motorhomes include alternator charging of the coach batteries as a standard feature, and it's capable of passing a substantial amount of current. Depending on the size of the LiFePO batteries, a DC-DC charger may be needed to limit the load on the alternator.

OTOH, a typical tow vehicle with a trailer connected by a 7-pin plug can't pass more than a few amps to the from the tow vehicle to the trailer. It's common for owners to install a separate power lead that can charge the batteries faster, in which case a DC-DC charger is recommended. That said, it's irrelevant to this discussion.

 

[Tim.D]

Thank you for the input. I did not think it would be that easy to do a swap over. I do not have solar. I have an onboard generator or plug in. The truck alternator is a 220amp oversized by Winnebago

 

[Bnystrom]

The next step is to determine if your converter or inverter/charger has a lithium setting. If it does, you're good. If it doesn't contact the manufacturer to see if they have an add-on lithium module for it.

 

[Tim.D]

After a quick look I have a WF-8955-AD which is Lithium capable and auto detects battery chemistry and charge profile.


Thanks for all the help Pointing me in the right direction.

 

[Goodspike]

Topping off the batteries to 100% can be easily accomplish with solar (if he has it and has a compatible charge controller) or with an inexpensive external charger. It should be done a handful of times per year. With proper monitoring, it's easy to tell if there is significant cell imbalance.

The lead-acid batteries DO have a fuse, it's just not located on the terminal. It's typically mounted on the side of the battery box. ALL batteries should be fused, regardless of their chemistry.

That's not a problem if you buy quality batteries, and you're grossly exaggerating the issue anyway. Yes, a Victron shunt is the "gold standard" and it certainly can't hurt to install one. However, the app for the SFK batteries I use displays cell voltages down to 1/100 of an amp, which eliminates the need for a shunt.

Actually, it's the other way around. Motorhomes include alternator charging of the coach batteries as a standard feature, and it's capable of passing a substantial amount of current. Depending on the size of the LiFePO batteries, a DC-DC charger may be needed to limit the load on the alternator.

OTOH, a typical tow vehicle with a trailer connected by a 7-pin plug can't pass more than a few amps to the from the tow vehicle to the trailer. It's common for owners to install a separate power lead that can charge the batteries faster, in which case a DC-DC charger is recommended. That said, it's irrelevant to this discussion.

You might be right about fuses and coach batteries, but I have not seen that. Still better to put it at the terminal since the reaction of a lithium battery to a short is much different than lead acid.

Agree on the solar comment, IF they have solar. I'd question though whether the 110v converter would properly restart a lithium battery that has shut down by the BMS where the auto detect feature doesn't know it's a lithium battery. Not something I've ever researched, but having once accidentally run down my battery I know how important that can be.

As for the shunt, the Victron shunt probably costs less than the price difference of buying a battery with a decent shunt.

As to the motorhome/tow vehicle issue, you're not understanding what I was thinking (because I didn't write it--not your fault). A tow vehicle is more likely to have an Orwellian named "smart alternator" which varies its voltage levels from 12.6-14.7 to improve MPG. If the alternator is only putting out 13v or less it will be discharging a lithium battery. A DC to DC charger will be charging the battery no matter the output voltage of the alternator. A motorhome (or heavy duty truck) is rather unlikely to have a smart alternator.

 

[Bnystrom]

You might be right about fuses and coach batteries, but I have not seen that. Still better to put it at the terminal since the reaction of a lithium battery to a short is much different than lead acid.

The ABYC recommends installing the fuse within 7" of the terminal, but there is no official standard for RVs. Sadly, that's the case for a lot of things in the RV industry.

Agree on the solar comment, IF they have solar. I'd question though whether the 110v converter would properly restart a lithium battery that has shut down by the BMS where the auto detect feature doesn't know it's a lithium battery. Not something I've ever researched, but having once accidentally run down my battery I know how important that can be.

Better quality batteries don't shut themselves down completely. For those that do, they can be restarted with a jump pack or charger provided that it will charge a battery that registers zero volts. Not all packs and chargers will, so if you have batteries that do fully shut down when drained, you need to make sure you get the proper charging device. Project Farm has done a lot of jump pack tests and that's one of the features he checks for.

From what I've seen, there are some converters that require battery voltage before they'll attempt to charge, so that's something to check with the manufacturer. The Parallax converter in our rig doesn't have that issue.

As for the shunt, the Victron shunt probably costs less than the price difference of buying a battery with a decent shunt.

Perhaps that's true in some circumstance, but It raises the broader question of whether a battery with poor monitoring is worth buying at all. To me, skimping on a component as critical to your camping enjoyment - and potentially safety - is false economy. Adding a shunt to a low-end "Amazon special" battery is a classic case of "putting lipstick on a pig". Buy good quality batteries; it's a one-time investment that's worth it for the peace of mind. Brands like SOK and SFK build great batteries at very competitive prices, and they stand behind their products.

As to the motorhome/tow vehicle issue, you're not understanding what I was thinking (because I didn't write it--not your fault). A tow vehicle is more likely to have an Orwellian named "smart alternator" which varies its voltage levels from 12.6-14.7 to improve MPG. If the alternator is only putting out 13v or less it will be discharging a lithium battery. A DC to DC charger will be charging the battery no matter the output voltage of the alternator. A motorhome (or heavy duty truck) is rather unlikely to have a smart alternator.

OK, that makes sense. I haven't had to deal with smart alternators, so I'll defer to you on that.

 

[Goodspike]

The ABYC recommends installing the fuse within 7" of the terminal, but there is no official standard for RVs. Sadly, that's the case for a lot of things in the RV industry.

On that topic it would probably be rather obvious where the furthest point would be based on the compartment and wire routing. I just like terminal fuses though because it goes to the closest possible point and could even protect against a short to the negative terminal while working with tools in the compartment, even if the negative cable had been removed to do the work.

Lead acid situation, but my last place of work had rather low quality maintenance people. Only one was qualified to do vehicle electrical IMHO. I once saw one of the others drop a wrench onto the battery hitting both terminals. I doubt that would have been a huge deal with lithium either, but likely it would have blown a terminal fuse.