LiFePO4 Battery Upgrade - New Converter?

[31Bullet]

I have a 2025 Bullet 2290BH we recently bought. It came with a lead-acid battery, but I found a great deal for a lithium battery and purchased it. I realize now that I'm not sure if the converter can charge the lithium battery. I know the Victron MPPT can switch to a lithium preset, but I'm not sure if the converter can do so.

Can I manually switch it? Or, does it automatically switch when it detects it? I've seen cases for both, but don't know about my specific trailer.

 

[NH_Bulldog]

You have to look at your converter brand and model number.

My 2024 Cougar came with a WFCO WF-9855-AD converter. The AD stands for auto detect. It initially worked ok with my lithium batteries, but then I discovered that the SolarFlex messes with the auto-detect feature. Both WFCO and Keystone blamed each other and neither would help me so I replaced my converter with a Progressive Dynamics unit that I can set to lithium and it will stay there.

Read my post #5 on this thread: https://www.keystoneforums.com/forums/showthread.php?p=578719#post578719

 

[GoingPlaces]

I guess I have Inquiring mind, and too much time on my hands.....


Did WFCO say how the Solar Flex interfered with the converter? It sounded like the WFCO converter was sensing voltage from the solar charger and interpreting that voltage as a lead acid battery being present. So, by turning off the solar charger, that solar voltage would not be present, and the converter would now determine that a Lithium battery was there. My question is what happens at night? Doesn't the solar system essentially turn off? I would think that since the solar charger cannot produce power to the battery then, that the converter would take over and finish the job of charging the battery at that point?

I have a WFCO with AD and will be moving to a Lithium battery this spring since my lead acid batteries are old. So, this thread is very timely.

 

[JRTJH]

The problem, in a short version answer, is that the WFCO "auto detect" feature ONLY works when the battery is "partially discharged" and the system triggers "bulk mode charging". It then "monitors the charging voltage for a change"... ONLY during bulk charging can the WFCO detect that "lithium footprint" and switch to the lithium profile... What happens with the solar system at night, is that the battery is essentially charged, so even with "no solar input" the WFCO won't go into "bulk charge mode" so it can't "switch back to lithium profile" as there's no "trigger voltage drop/lithium profile characteristics" to trigger the mode change.

So, during the day, the solar system "influences your WFCO to switch to FLA mode. Then at night, there's no influence, but the WFCO has no "bulk mode trigger to cause the change back to lithium mode"....

That's the part that WFCO and Keystone are arguing about (or more likely, ignoring so far).... I'd suspect that the end solution will be that WFCO installs an "FLA/LI switch" in the AD converter/chargers so owners can either allow "auto detect if they have no solar system" or they can "lock out FLA mode if they do have a solar system that interferes with the AD program".... Until then, there will be issues with the auto detect feature on WFCO converter/chargers in Keystone trailers with the SolarFlex system and lithium batteries.

 

[GoingPlaces]

So, I should use the heck out of the battery after the sun goes down to trigger the converter into charging and hopefully be done before daybreak.

On sunny days I assume the Solar Charger would finish charging the battery or at least try to. I am assuming that a Lithium charge mode is present on the solar charger.

 

[NH_Bulldog]

You need to adjust settings on the solar charge controller for it to “recognize” the LiFePO4 batteries. It is easy to do and the process is clearly laid out on the Victron site.

In my extensive conversations with the techs from both Keystone and WFCO their “solution” was to shut off the solar anytime you are on shore power in order for the converter to reliably and consistently auto detect the LiFePO4 batteries. Otherwise, no matter how hard you try to get it to stay in lithium charging, with the solar on it will always revert back to lead acid profile.

Although I did initially buy a Progressive Dynamics converter with an actual switch to change charging, I returned it after another member here suggested I give WFCO another shot at it. After another conversation with WFCO they agreed to modify my existing converter by adding a little jumper plug inside to make it lithium-only (and showed me where it was located so I could remove it at a later date if I wanted). As a side benefit, they also updated the unit firmware.

 

[GoingPlaces]

I have a Zamp Solar charge controller in my rig, as delivered from the factory.

I don't know how to shut off the solar system. I don't believe there is a switch or setting on the controller. Or is there and I've never paid attention? Now I'm curious, I'll need to investigate next time I'm at the trailer.

 

[NH_Bulldog]

I can’t speak to the Zamp controller or why it is different; maybe an early solar setup, maybe a Covid-era build, maybe because it is a TT? No idea, but the controller should still have settings/menu for different battery types and charging parameters. I also cant speak to whether you have a solar disconnect or not. Mine has one right next to the solar charge controller (in the upper right of this picture).

 

[GoingPlaces]

The Zamp controller does have different battery type settings. It came with it set to AGM so I had to change that.

Where does the switch set it the circuit, before to controller I'd assume. Is it a special switch? Does it disconnect both the positive and negative wires, I can't tell in the photo what wires actually go into that switch. I've often thought it would be a good thing to have, especially when messing with the batteries.

I do have a switch like that next to the inverter, but it is only for it.

 

[NH_Bulldog]

The solar disconnect is inline on the positive wire between the solar panels and the charge controller. The power to the charge controller is disconnected when the main disconnect on the Givgy box is switched off. That picture is from before I installed my inverter and an inverter disconnect.

 

[Stircrazy]

The Zamp controller does have different battery type settings. It came with it set to AGM so I had to change that.

Where does the switch set it the circuit, before to controller I'd assume. Is it a special switch? Does it disconnect both the positive and negative wires, I can't tell in the photo what wires actually go into that switch. I've often thought it would be a good thing to have, especially when messing with the batteries.

I do have a switch like that next to the inverter, but it is only for it.

a lot of systems didn't have disconnects when solar first started being put on at the dealership. what was normally in the instructions was to cover your panels with a heavy blanket or cardboard before removing the batteries or doing any work on the controller. my 5th wheel that I had the dealer put the solar in when I bought it doesn't have any either so when I do my upgrades I am adding them myself.