Lithium w/OEM Converter/Charger...what I've learned

[Riverbug]

I plan to install solar in 2022. In the meantime, I replaced the cheap 25AH flooded lead acid battery that came with my TT with a 206AH lithium battery (with Victron battery monitor). Because I will install a Victron Multiplus next year, I left the existing WFCO control center in place for now. Of course the model that came with the TT is not designed specifically for lithium. To my surprise, over the past month it has consistently kept my battery charged to 77% of capacity. Lithium battery life can be greatly extended when charged to 80% vs 100% and recharged at 20% vs 0%. There is no harm in using the full capacity (100% to 0%) but manufacturers suggest that you can double or triple battery life by not using the full capacity. Anyway, just thought I would share my findings for anyone that was thinking you simply cannot use the original WFCO charger with a lithium battery...

[Paul & Deb]

Well that's interesting! I've never heard of a 25 amp hr battery! What the heck was your dealer thinking? That sounds like a motorcycle battery! Even a basic RV/Marine deep cycle battery is like 90 ah. Most of the 2022's I've heard of with the solar panel and 12v fridge are coming with 2 deep cycles or at least that's what my dealer is installing. Dang!

My 2022 22MLE is due in any day and I already have my 206 ah SOK on it's way and will add a second for 412 ah.

On my 2021 17MKE I continued to use the factory converter with my 2 105 ah LION Safari UT 1300 lithiums but I also had 400 watts of roof top solar so they kept the batteries at 100% SOC.

There is a simple swap out for your factory WFCO 8735 power center/converter. The WFCO 8735 LiS includes a switchable converter so you can charge lead acid or lithium. I think Progressive Dynamics makes a similar power center. Not sure which way I will go with the new unit until I get my hands on it.

[Riverbug]

Well that's interesting! I've never heard of a 25 amp hr battery! What the heck was your dealer thinking? That sounds like a motorcycle battery! Even a basic RV/Marine deep cycle battery is like 90 ah. Most of the 2022's I've heard of with the solar panel and 12v fridge are coming with 2 deep cycles or at least that's what my dealer is installing. Dang!

My 2022 22MLE is due in any day and I already have my 206 ah SOK on it's way and will add a second for 412 ah.

On my 2021 17MKE I continued to use the factory converter with my 2 105 ah LION Safari UT 1300 lithiums but I also had 400 watts of roof top solar so they kept the batteries at 100% SOC.

There is a simple swap out for your factory WFCO 8735 power center/converter. The WFCO 8735 LiS includes a switchable converter so you can charge lead acid or lithium. I think Progressive Dynamics makes a similar power center. Not sure which way I will go with the new unit until I get my hands on it.

Yeah, I was surprised about the 25AH battery too. It's a group 27 and the label calls it a marine/rv battery, but I've never heard of one with such low capacity either. I just assumed that's what they put in them these days since the dealer provides the battery. I did see that there is a swap for the WFCO but I've already decided on Victron when I install panels next year. I don't want to waste money on replacing the existing control center since it will not be needed once I install the Victron. I also purchased the SOK; very happy with it so far. I may also purchase a second battery when I do the solar next year. Regarding the 2022's, mine was complete just before they started installing the 12v fridge with solar. I was fairly disappointed when I learned that. But we're happy with the rig so it is what it is at this point.

[Paul & Deb]

Yeah, I was surprised about the 25AH battery too. It's a group 27 and the label calls it a marine/rv battery, but I've never heard of one with such low capacity either. I just assumed that's what they put in them these days since the dealer provides the battery. I did see that there is a swap for the WFCO but I've already decided on Victron when I install panels next year. I don't want to waste money on replacing the existing control center since it will not be needed once I install the Victron. I also purchased the SOK; very happy with it so far. I may also purchase a second battery when I do the solar next year. Regarding the 2022's, mine was complete just before they started installing the 12v fridge with solar. I was fairly disappointed when I learned that. But we're happy with the rig so it is what it is at this point.

Did you install the battery under the bed, in the pass through or leave it on the tongue?

[xrated]

I am probably going to build a 12V LFP battery later this year, or early next year before the start of camping season. My plans are for four 320AH CATL 3.2V cells protected by a Daly 200A Smart BMS. All of this is going to be done in preparation for switching out the 18 cu. ft. Norcold 2118. I've just about had it with that fridge (that's another story for a different thread), but my plan is to either get the Norcold converted over to a 12V compressor cooling unit at JC Refrigeration, or just remove the Norcold and buy a new 17 cu. ft. standalone 12V compressor fridge. The one I have looked at uses on average of 75W/hour and with a 320AH LFP battery system onboard (I'll probably just run it down to 10% SOC) that is still almost 290AH...which should provide approx. 3,450 watt and that works out to around 46-47 hours of runtime for the fridge. When all of that gets done....or maybe even before I do the fridge mod or swap, I'll be getting a Progressive Dynamics PD9160ALV for a converter/LFP charger and installing it in trailer. My present converter might be OK as it doe have automatic three stage charging...but I would rather have a converter/charger that is specifically made for LiFePo4 chemistry.

[Riverbug]

Did you install the battery under the bed, in the pass through or leave it on the tongue?

I put mine under the dinette where the water pump is. When we add the solar package, I will likely cut the panel that is on the backside of the dinette (under the seat) and then use the space behind the WFCO. There's quite of bit of space there. Between those areas, two batteries and a Multiplus should fit nicely. I may also move the pump and wiring so that it is tucked to the side rather than in the middle of the space under the dinette.

[Riverbug]

I am probably going to build a 12V LFP battery later this year, or early next year before the start of camping season. My plans are for four 320AH CATL 3.2V cells protected by a Daly 200A Smart BMS. All of this is going to be done in preparation for switching out the 18 cu. ft. Norcold 2118. I've just about had it with that fridge (that's another story for a different thread), but my plan is to either get the Norcold converted over to a 12V compressor cooling unit at JC Refrigeration, or just remove the Norcold and buy a new 17 cu. ft. standalone 12V compressor fridge. The one I have looked at uses on average of 75W/hour and with a 320AH LFP battery system onboard (I'll probably just run it down to 10% SOC) that is still almost 290AH...which should provide approx. 3,450 watt and that works out to around 46-47 hours of runtime for the fridge. When all of that gets done....or maybe even before I do the fridge mod or swap, I'll be getting a Progressive Dynamics PD9160ALV for a converter/LFP charger and installing it in trailer. My present converter might be OK as it doe have automatic three stage charging...but I would rather have a converter/charger that is specifically made for LiFePo4 chemistry.

Sounds like it would be a nice setup. And I do agree that having a charger specifically for lithium is best. I just wanted to point out that the OEM charger does work; obviously it charges slower and not to 100%. But I've seen others in the same boat where they want to upgrade the battery first and haven't figured out what they will do yet for solar, charger, inverters. Knowing that we can replace a battery with lithium before making the other investments is a nice option.

[xrated]

Sounds like it would be a nice setup. And I do agree that having a charger specifically for lithium is best. I just wanted to point out that the OEM charger does work; obviously it charges slower and not to 100%. But I've seen others in the same boat where they want to upgrade the battery first and haven't figured out what they will do yet for solar, charger, inverters. Knowing that we can replace a battery with lithium before making the other investments is a nice option.

Don't get me wrong, I agree with what you posted, and not switching to a LFP style charger wouldn't be near as much of an issue if solar is used to supplement the charging process. From what I've read (and I might be wrong on this)....LFP batteries like to be charged to 100%, but....there is also a thought that using them between a 90%-10% SOC range will also very likely extend the life of the batteries. I'm still a total rookie in regard to LFP type batteries and have a lot to learn, even though I've been a Journeyman Electrician for over 40 years (Hey....no body knows everything about everything in regard to electrical stuff LOL)

And the reason that I would switch to a LFP type charger fairly quickly (either before or very shortly after the battery install) is that I have zero interest in putting solar panels on my trailer....as we really don't boondock and don't have any plans to. I guess that would be a pretty big factor in the decision of how much battery reserve to have, whether or not you need/want solar, and the charger decision implementation timeline.

My primary goal is to get a refrigerator that I feel is as close to 100% dependable as possible......and the Norcold in it's OEM configuration, even with the mods I've done to it, just isn't cutting it for me. I simply do not want the worry of whether or not the fridge will work at an acceptable level, or have me concerned about losing food because the temperatures will not stay cold enough. The LFP batteries/charger and switching the Norcold to a 12V compressor system will go a long way (hopefully) towards achieving that goal.......then it will be on to the next project/mod, whatever that is.

[Riverbug]

Don't get me wrong, I agree with what you posted, and not switching to a LFP style charger wouldn't be near as much of an issue if solar is used to supplement the charging process. From what I've read (and I might be wrong on this)....LFP batteries like to be charged to 100%, but....there is also a thought that using them between a 90%-10% SOC range will also very likely extend the life of the batteries.

All you said makes sense. But just FYI, the LFP batteries don't "like" to be charged to 100% and they don't need to be for any reason other than getting as much capacity out of them as you can - of course, it doesn't hurt them either as that's what they are built for. I asked SOK what the best charge limits are for longevity for the 206AH battery I purchased from them, knowing that at the moment I don't need the full capacity as we have not started boondocking yet. What I stated above was based on their recommendation. Hope that helps.

[IntegrityImportService]

I installed 800AH of LifePO4 batteries and accessories. Figured out that the factory converter was sucking up 300w of juice. I just flipped the breaker inside of the converter for the charger to off. Works fantastic. I use the multi and solar for charging.