Planning Stage Switching to Lithium Battery

[Steven@147]

Be aware that a charging "test" when you are not using the unit will always give much better results than when you are using the RV....Reason being that you will be consuming power that would have been used to charge the battery.
This difference can be quite large

Yes, Now just sitting here plugged into AC power running the normal stuff on AC and DC, seeing the 55 amp converter carry the coach load (not much) at the same time as charging the LifePO4 battery is one thing. Just sitting here there's not much DC load on the converter (lights, DC fans, DC appliance control boards and the like)(unless we use the leveling system or run the slides) majority of the power load just setting here is running on AC.

Once we get the fridge mod done then the real actual result analysis will be seen when, on AC power, off AC power, on generator or on truck power. I don't know about the power consumption load of the 12VDC fridge, I don't expect the fridge to run continuously once cold but on and off as the thermostat settings dictate and with ambient temps. Much is yet to be seen

 

[triplethreat]

Yes, Now just sitting here plugged into AC power running the normal stuff on AC and DC, seeing the 55 amp converter carry the coach load (not much) at the same time as charging the LifePO4 battery is one thing. Just sitting here there's not much DC load on the converter (lights, DC fans, DC appliance control boards and the like)(unless we use the leveling system or run the slides) majority of the power load just setting here is running on AC.

Once we get the fridge mod done then the real actual result analysis will be seen when, on AC power, off AC power, on generator or on truck power. I don't know about the power consumption load of the 12VDC fridge, I don't expect the fridge to run continuously but on and off as the thermostat settings dictate and with ambient temps. Much is yet to be seen

I don't know if you've seen my postings in other threads or not about my Norcold 2118 being converted over to the JC Twin Compressor mod. It's an 18.xx cu ft. model so the compressors may or may not be the same as what you will be getting, but the results I see are that in a 24 hour period of time, the fridge will use approx. 145AH of battery. When both compressors are running at the same time, as it common when a unit is first turned on, or sometimes when under usage and they just happen to be needed at the same time.....the current flow to the fridge with Both compressors running is 12.6 amps. Just some info for you, and like I said, it may or may not be exactly like your results because of different compressors, etc.

 

[Steven@147]

I'd be concerned about the length of time that the WFCO took to charge the 100AH battery from 50% SOC to almost full. If those numbers are true....it actually being at 50% SOC, you are only talking about putting an additional 50AH into the battery and for it to take 7 hours to do that, something is not correct. I'll give you and example: My 302AH battery at 50% SOC should have approx. 150AHs in it, and need another 150AH to be full. When my charger starts charging in the bulk/Constant Current mode, it is putting out 42/43 amps....and the Converter Charger is only capable of 43.xx amps. Of course after the Constant Current mode is done, it switches to Constant Voltage mode to finish it off, then float. So assuming that most of the charging is done in the bulk mode (42/43 amps going in), it should take less than four hours to go that additional 50%.....or 150AHs. In your case, with a 100AH, it only needs another 50AH.....and for it to take 7 hours to do that, averages out to a charging rate of 7 amps. Like I said, something is amiss there.

Watching the battery app while the WFCO 9855 AD converter by itself was initially charging up the battery from 50% SOC up to @ 85% SOC the max amp going into the battery was real low around 4 amps @ 13.6 VDC (according to the battery app) and from @ 85- 98% SOC it went down even lower @ 3.5 amps going into the battery again according to the battery app. I assume that is why it took so long.

That's why I got the dedicated free standing LifePO4 charger, I am Not relying on the WFCO to do the baulk of battery charging. I am only relying on the WFCO to carry the coach DC load (lights, DC fans, AC unit DC thermostats, DC control boards, water pump if used and such) which isn't much in normal RV operation on AC power.
But i don't have the LifePo4 charger yet, it will be here tomorrow.

 

[triplethreat]

Watching the battery app while the WFCO 9855 AD converter by itself was initially charging up the battery from 50% SOC up to @ 85% SOC the max amp going into the battery was real low around 4 amps @ 13.6 VDC (according to the battery app) and from @ 85- 98% SOC it went down even lower @ 3.5 amps going into the battery again according to the battery app. I assume that is why it took so long.

That's why I got the dedicated free standing LifePO4 charger, I am Not relying on the WFCO to do the baulk of battery charging. I am only relying on the WFCO to carry the coach DC load (lights, DC fans, AC unit DC thermostats, DC control boards, water pump if used and such) which isn't much in normal RV operation on AC power.
But i don't have the LifePo4 charger yet, it will be here tomorrow.

Yep, you're correct. A 50% SOC level on the battery would approx. 13.1 volts, although, as you know, voltage checking is pretty much a futile way of determining SOC on LFP batteries since their voltage curve is so flat except on the bottom and top end when you get into the "knee" area of the charge or discharge. And quite literally, 13.6V is about .2 or .3 volts away from being able to charge fully. As you know, 3.45 volts per cell/13.8 volts for the battery, is considered to be at approx. 100% SOC and the low....13.6 volts just isn't enough to push a lot of current into the battery.

Just curious.....what the amperage rating is on the new, as yet to arrive free standing charger you have ordered?

 

[Steven@147]

Yep, you're correct. A 50% SOC level on the battery would approx. 13.1 volts, although, as you know, voltage checking is pretty much a futile way of determining SOC on LFP batteries since their voltage curve is so flat except on the bottom and top end when you get into the "knee" area of the charge or discharge. And quite literally, 13.6V is about .2 or .3 volts away from being able to charge fully. As you know, 3.45 volts per cell/13.8 volts for the battery, is considered to be at approx. 100% SOC and the low....13.6 volts just isn't enough to push a lot of current into the battery.

Just curious.....what the amperage rating is on the new, as yet to arrive free standing charger you have ordered?

20 amps on the new charger on the way.

Right now the battery app is showing 13.64 V - 0 amps - 0 W power (no power coming out of the battery). Each cell is measuring 3.42, 3.41, 3.41 , 3.41 and it's showing 98% charged and 102.41 AH capacity.
I really wish these battery apps come with some kind of guide to define some of what its showing, but I guess its showing what I really want to know.

Now JC says if you don't boondock a single LA or AGM is enough to hold the fridge while traveling. Well I guess that depends on how many hours someone travels. But well see what happens after we get the fridge mod and do some real world testing measuring.

 

[triplethreat]

20 amps on the new charger on the way.

Right now the battery app is showing 13.64 V - 0 amps - 0 W power (no power coming out of the battery). Each cell is measuring 3.42, 3.41, 3.41 , 3.41 and it's showing 98% charged and 102.41 AH capacity.
I really wish these battery apps come with some kind of guide to define some of what its showing, but I guess its showing what I really want to know.

Now JC says if you don't boondock a single LA or AGM is enough to hold the fridge while traveling. Well I guess that depends on how many hours someone travels. But well see what happens after we get the fridge mod and do some real world testing measuring.

Well, some folks will tell you that 3.4V per cell would be fully charged, other bump that to 3.45 volts per cell. And the difference between those two number comes out to 13.6 vs. 13.8 volts for the battery. In a perfect world of camper battery/charger/wiring situation (which almost never happens) 13.8 volts will definitely get a LFP battery charged to 100% SOC. There two problems with that statement though....1. It will take forever and a day for that 100% SOC to show up. 2. Most systems are going to have at least "some" voltage drop from the charger terminals all the way to the battery. Voltage drop happens or could happen because of wiring not being properly sized (internal resistance of that size wire and the length of the run), not perfect crimps on the lug/wire connection, excessive resistance through a battery disconnect switch, excessive resistance on terminal strip connections, etc.

When I first installed my DIY battery and was going to give all the OEM wiring/switches/connections that I could reuse, and see what voltage I was actually getting at the battery terminal vs. the output voltage from the Converter/Charger. I ended up with a .6 to .7 volt drop between the converter/charger and the battery terminals. That has to be measured while current is flowing to the battery during charging. So the converter/charger output of 13.6 volts was actually down to 13.0 or 12.9 volts by the time it got to the battery......Simply NOT acceptable for a LFP battery installation.

So, to correct all of that, I did the following things...
1. Bought a new Converter/Charger that I knew would work properly and give me the number that I wanted.
2. Moved the new Converter/Charger a lot closer to the battery
3. Ditched the 6ga wire and went with 2ga wire.
4. Obviously new wire (and larger gauge) requires new crimp connectors
5. Replaced the OEM battery disconnect with a Blue Seas heavy duty switch
6. Cleaned and polished all terminals/connection points, including the new 300A buss bars that I installed during the battery installation.
7. Checked all work done for good connections and tightness of those connections.

As a result of all of that, the new Converter/Charger output voltage of 14.2 when in Constant Voltage stage, now sends all of that voltage to the battery terminals....minus .1 volt. So my battery is now seeing 14.1 and I'm perfectly OK with that. And that 1/10 of volt drop is while the battery is receiving 42/43 amps.....and the new charger is capable of 43.xx amps, so that is in my opinion....a good converter to battery charging loop as evidenced by only 1/10 of a volt drop while pulling maximum current from the charger to the battery.

 

[Steven@147]

[MENTION=21739]xrated[/MENTION]
See this is exactly what I didn't want to have to do just to switch to a LifePo4 battery. Because of where the WFCO converter is located and the way they have our coach wired, you darn near have to gut the fish and spend huge amounts of money and time to get it done.

Like the power has to come from the converter in center storage compartment, go back to the distribution panel mid coach by the stairs, then go all the way up forward to the battery in the front storage compartment, makes for a long run of 6awg, with lots of interconnections, but to make it more efficient remove and upsize the wire and all sort of other stuff.

No thank you, So now when I install the New LifePO4 20 amp charger right beside the new battery in the front storage compartment, that eliminates a whole lot of lost charging power. Leaving everything as it is,True some lost battery power capability running it all the way from the front storage compartment to the distribution panel mid coach on the stairs all with 6 awg through all the miscellaneous connections. But then again I'm not trying to power the space shuttle through an entire mission, Just trying to supply 12V power off AC grid for a few hours.

 

[huntindog]

[MENTION=21739]xrated[/MENTION]
See this is exactly what I didn't want to have to do just to switch to a LifePo4 battery. Because of where the WFCO converter is located and the way they have our coach wired, you darn near have to gut the fish and spend huge amounts of money and time to get it done.

Like the power has to come from the converter in center storage compartment, go back to the distribution panel mid coach by the stairs, then go all the way up forward to the battery in the front storage compartment, makes for a long run of 6awg, with lots of interconnections, but to make it more efficient remove and upsize the wire and all sort of other stuff.

No thank you, So now when I install the New LifePO4 20 amp charger right beside the new battery in the front storage compartment, that eliminates a whole lot of lost charging power. Leaving everything as it is,True some lost battery power capability running it all the way from the front storage compartment to the distribution panel mid coach on the stairs all with 6 awg through all the miscellaneous connections. But then again I'm not trying to power the space shuttle through an entire mission, Just trying to supply 12V power off AC grid for a few hours.

How exactly will you use this additional charger? Will you disconnect the convertor, or turn it off?

 

[triplethreat]

[MENTION=21739]xrated[/MENTION]
See this is exactly what I didn't want to have to do just to switch to a LifePo4 battery. Because of where the WFCO converter is located and the way they have our coach wired, you darn near have to gut the fish and spend huge amounts of money and time to get it done.

Like the power has to come from the converter in center storage compartment, go back to the distribution panel mid coach by the stairs, then go all the way up forward to the battery in the front storage compartment, makes for a long run of 6awg, with lots of interconnections, but to make it more efficient remove and upsize the wire and all sort of other stuff.

No thank you, So now when I install the New LifePO4 20 amp charger right beside the new battery in the front storage compartment, that eliminates a whole lot of lost charging power. Leaving everything as it is,True some lost battery power capability running it all the way from the front storage compartment to the distribution panel mid coach on the stairs all with 6 awg through all the miscellaneous connections. But then again I'm not trying to power the space shuttle through an entire mission, Just trying to supply 12V power off AC grid for a few hours.

Steve....in all fairness, we each have to decide what is the best "route" or plan for our improvements. I too, did not want to have to do a re-wire on the charging/12VDC system, but the less than stellar results with the OEM Converter/Charger (WFCO 9855) and the fact that I had so many components dropping voltage between the C/C and the battery, pretty much made it something that needed to be done. So when I relocated the new C/C, I moved it to a location that was more in the middle of everything.....approx. halfway to the 12VDC fuse distribution panel and approx. halfway to the battery in the front compartment where the generator and hydraulics are located. In fact, I left the OEM 6ga wire in place that goes from the C/C to the 12VDC distribution panel.....which has the smaller 12V loads on it....lights, fans, etc. Then the wiring from the C/C to the new battery disconnect switch is 2ga wire. From there to the 300A buss is 2ga wire, and then the new connections, etc. I think the results speak for themselves though....a C/C that is capable of only 43.xx amps (Meanwell NPB 750-12) and I am seeing 42.xx/43.xx amps flowing to the battery during the bulk charging stage and the measured voltage drop of 1/10 of a volt. For me, that is success. That certainly DOESN'T mean that it is the ONLY way to do it and that my way is correct and everything or anything different is wrong, it simply means that what I did worked great, and it was what I chose to do in order to fix my situation.
Here is a pic of the relocated Converter/Charger....mounted overhead in the storage compartment right behind the curbside propane compartment. Easy access and as you can see, one set of wires going forward (2ga for the battery charging circuits) and two going the other direction (heading to the 12VDC fuse distribution panel)

 

[Steven@147]

How exactly will you use this additional charger? Will you disconnect the convertor, or turn it off?

I'll leave the WFCO converter on with normal operation of the RV and it will keep the battery near 102%. After we get the fridge mod done, off AC grid while we travel, the fridge will be running off 12V most likely connected directly to the battery. We mostly travel @ 5 hours max so when we get to our next campground and if the battery SOC is down a lot I'll plug in turn on the new LifePo4 charger to get the battery back up to 102-105% more quickly overnight than the WFCO can. Once the battery SOC is back up, then turn the new charger off.

From what I've seen the WFCO converter can charge the LifePO4 battery up to 98-99% but it takes it a long time because as the SOC nears 90 % the WFCO charge amps is down near 2 amps. So I intend to use the new LifePO4 charger to quickly bring the battery back up to full charge, then turn it off.

I still have to see exactly how much power the 12V fridge mod uses and then see how much power the truck will provide while traveling. The battery bluetooth should show how much power is going out to power the fridge and how much power is coming in from the truck.

 

[Steven@147]

Steve....in all fairness, we each have to decide what is the best "route" or plan for our improvements. I too, did not want to have to do a re-wire on the charging/12VDC system, but the less than stellar results with the OEM Converter/Charger (WFCO 9855) and the fact that I had so many components dropping voltage between the C/C and the battery, pretty much made it something that needed to be done. So when I relocated the new C/C, I moved it to a location that was more in the middle of everything.....approx. halfway to the 12VDC fuse distribution panel and approx. halfway to the battery in the front compartment where the generator and hydraulics are located. In fact, I left the OEM 6ga wire in place that goes from the C/C to the 12VDC distribution panel.....which has the smaller 12V loads on it....lights, fans, etc. Then the wiring from the C/C to the new battery disconnect switch is 2ga wire. From there to the 300A buss is 2ga wire, and then the new connections, etc. I think the results speak for themselves though....a C/C that is capable of only 43.xx amps (Meanwell NPB 750-12) and I am seeing 42.xx/43.xx amps flowing to the battery during the bulk charging stage and the measured voltage drop of 1/10 of a volt. For me, that is success. That certainly DOESN'T mean that it is the ONLY way to do it and that my way is correct and everything or anything different is wrong, it simply means that what I did worked great, and it was what I chose to do in order to fix my situation.
Here is a pic of the relocated Converter/Charger....mounted overhead in the storage compartment right behind the curbside propane compartment. Easy access and as you can see, one set of wires going forward (2ga for the battery charging circuits) and two going the other direction (heading to the 12VDC fuse distribution panel)
View attachment 51010

I didn't mean to seem critical, my sincere apologies if it seemed that way. I agree with you totally. You had given me invaluable information earlier and I was all set to get into rewiring and relocating stuff and installing new bus bars, cut off switches and a new Progressive Dynamics converter and get it all straightened and as efficient as possible, out in anticipation of getting our fridge converted over to 12V.

We have got to do something with the fridge, and get the 12V dual compressor mod done, our Dometic 110/propane is just too unreliable in hot weather with the temps inside the fridge going up and down like a yo-yo. When traveling the temp inside the fridge could be 40+* by the time we get to our next campsite. We don't travel with the propane on. So getting the fridge converted to 12V means it would be more stable and we can travel with it turned on (as long as we have a battery to support it). That's where a new lithium batt comes in. Then i got to looking at everything I was going to do about rewiring and changing out the WFCO converter, the cost and time. Would it really be worth it just to support a converted fridge?

Tami and I got to talking about how much time and money it would take for my plan to convert to lithium batteries and do the rewiring like I had planned. She asked would it be really worth it since we have agreed that we don't want to do any boondocking going forward. She asked if there was a more simple way to do it.

It was kinda cool the few times we stayed at HH sites and boondocked a couple times. But we like full hookups from now on. We're dropping Harvest Hosts, we just won't use it. We are wimps I guess, not that much adventurous any more ! So that's how I came up with this new plan. Just leave everything alone, install a new lithium battery, see how the WFCO 9855 AD will do. Then reading other owners posting about what they have done and I came upon just installing a new LifePO4 standalone 20 amp charger right beside the new LifePO4 battery and switch it on to quickly bring the lithium battery back up to full power then switch it off. So all in we're less than $300 to get lithium and a few minutes installation time.

 

[robmcqueen]

I didn't mean to seem critical, my sincere apologies if it seemed that way. I agree with you totally. You had given me invaluable information earlier and I was all set to get into rewiring and relocating stuff and installing new bus bars, cut off switches and a new Progressive Dynamics converter and get it all straightened and as efficient as possible, out in anticipation of getting our fridge converted over to 12V.

We have got to do something with the fridge, and get the 12V dual compressor mod done, our Dometic 110/propane is just too unreliable in hot weather with the temps inside the fridge going up and down like a yo-yo. When traveling the temp inside the fridge could be 40+* by the time we get to our next campsite. We don't travel with the propane on. So getting the fridge converted to 12V means it would be more stable and we can travel with it turned on (as long as we have a battery to support it). That's where a new lithium batt comes in. Then i got to looking at everything I was going to do about rewiring and changing out the WFCO converter, the cost and time. Would it really be worth it just to support a converted fridge?

Tami and I got to talking about how much time and money it would take for my plan to convert to lithium batteries and do the rewiring like I had planned. She asked would it be really worth it since we have agreed that we don't want to do any boondocking going forward. She asked if there was a more simple way to do it.

It was kinda cool the few times we stayed at HH sites and boondocked a couple times. But we like full hookups from now on. We're dropping Harvest Hosts, we just won't use it. We are wimps I guess, not that much adventurous any more ! So that's how I came up with this new plan. Just leave everything alone, install a new lithium battery, see how the WFCO 9855 AD will do. Then reading other owners posting about what they have done and I came upon just installing a new LifePO4 standalone 20 amp charger right beside the new LifePO4 battery and switch it on to quickly bring the lithium battery back up to full power then switch it off. So all in we're less than $300 to get lithium and a few minutes installation time.

Sound like a great plan. Have you thought about adding a small solar set up to help keep batteries charged on travel days ?

 

[huntindog]

I'll leave the WFCO converter on with normal operation of the RV and it will keep the battery near 102%. After we get the fridge mod done, off AC grid while we travel, the fridge will be running off 12V most likely connected directly to the battery. We mostly travel @ 5 hours max so when we get to our next campground and if the battery SOC is down a lot I'll plug in turn on the new LifePo4 charger to get the battery back up to 102-105% more quickly overnight than the WFCO can. Once the battery SOC is back up, then turn the new charger off.

From what I've seen the WFCO converter can charge the LifePO4 battery up to 98-99% but it takes it a long time because as the SOC nears 90 % the WFCO charge amps is down near 2 amps. So I intend to use the new LifePO4 charger to quickly bring the battery back up to full charge, then turn it off.

I still have to see exactly how much power the 12V fridge mod uses and then see how much power the truck will provide while traveling. The battery bluetooth should show how much power is going out to power the fridge and how much power is coming in from the truck.

Got it.
There is a possibility that your convertor and your new charger will not play nice together. IOW one of them will sense the voltage from the other and see it as a charged battery and reduce it's output. Then you would need to only run one at a time, meaning you would not gain much if anything.
.With your new charger only being 20 amps..... Have to test it to see, but I have read of this happening.
Now if you had a 55 amp lithium charger, you would be in good shape for sure

 

[triplethreat]

I didn't mean to seem critical, my sincere apologies if it seemed that way. I agree with you totally. You had given me invaluable information earlier and I was all set to get into rewiring and relocating stuff and installing new bus bars, cut off switches and a new Progressive Dynamics converter and get it all straightened and as efficient as possible, out in anticipation of getting our fridge converted over to 12V.

We have got to do something with the fridge, and get the 12V dual compressor mod done, our Dometic 110/propane is just too unreliable in hot weather with the temps inside the fridge going up and down like a yo-yo. When traveling the temp inside the fridge could be 40+* by the time we get to our next campsite. We don't travel with the propane on. So getting the fridge converted to 12V means it would be more stable and we can travel with it turned on (as long as we have a battery to support it). That's where a new lithium batt comes in. Then i got to looking at everything I was going to do about rewiring and changing out the WFCO converter, the cost and time. Would it really be worth it just to support a converted fridge?

Tami and I got to talking about how much time and money it would take for my plan to convert to lithium batteries and do the rewiring like I had planned. She asked would it be really worth it since we have agreed that we don't want to do any boondocking going forward. She asked if there was a more simple way to do it.

It was kinda cool the few times we stayed at HH sites and boondocked a couple times. But we like full hookups from now on. We're dropping Harvest Hosts, we just won't use it. We are wimps I guess, not that much adventurous any more ! So that's how I came up with this new plan. Just leave everything alone, install a new lithium battery, see how the WFCO 9855 AD will do. Then reading other owners posting about what they have done and I came upon just installing a new LifePO4 standalone 20 amp charger right beside the new LifePO4 battery and switch it on to quickly bring the lithium battery back up to full power then switch it off. So all in we're less than $300 to get lithium and a few minutes installation time.

Steve....no worries, I didn't take it as critical the way you expressed it. It is what you wanted to do and you followed up with your plan.....no one can fault you for that. One thing you have to remember though, I've been a Journeyman Electrician since 1980 and my mind probably works differently than some folks. The downside to that is that sometimes I may have a tendency to overlook a simpler solution because I've dug my heels in and know what the issue is, so by golly I'm going to fix "THAT" issue. Sometimes it's a blessing, and once in a while it's a curse.....LOL!

 

[Butcher]

I may have a tendency to overlook a simpler solution because I've dug my heels in and know what the issue is, so by golly I'm going to fix "THAT" issue.

I've never done that

 

[triplethreat]

I've never done that

LOL.....I can relate to that. I've only been wrong once in my life........One time I thought I was wrong, but I wasn't!

 

[Steven@147]

Well shoot guys, sorry I haven't been around for a few days, I just got out of the Hospital due to an emergency. Long story that has to do with MEN1 Syndrome. I lost all track of what I was doing with this Lifepo4 thing and can't even think about it for a few days.

I have been ordered by Tami to take it easy, I have my marching orders and I must OBEY!

 

[Hoopy Frood]

Sorry to hear that. Hope you have it under control.

 

[SolarPoweredRV]

Well shoot guys, sorry I haven't been around for a few days, I just got out of the Hospital due to an emergency. Long story that has to do with MEN1 Syndrome. I lost all track of what I was doing with this Lifepo4 thing and can't even think about it for a few days.

I have been ordered by Tami to take it easy, I have my marching orders and I must OBEY!

Sorry to hear about your diagnosis, I do hope you get better soonest.

Best of luck to you and your family.

Sincerely,

David and Peggy

 

[Steven@147]

Got it.
There is a possibility that your convertor and your new charger will not play nice together. IOW one of them will sense the voltage from the other and see it as a charged battery and reduce it's output. Then you would need to only run one at a time, meaning you would not gain much if anything.
.With your new charger only being 20 amps..... Have to test it to see, but I have read of this happening.
Now if you had a 55 amp lithium charger, you would be in good shape for sure

I'm back, so about the only thing I can do right now is converse with y'all here.
I can see where that could happen with both chargers on. I thought maybe I could use the OEM battery disconnect switch. That would isolate the battery from the RV and the WFCO converter, while the external 20 amp LifePo4 charger charges the battery, The WFCO converter would supply the RV systems with 12V.

Well that isn't going to work. The way JC Refrigeration connects the new 12V dual compressor fridge, they connect it directly to the battery, or the 12V bus bar in the front cargo hold before the disconnect switch. That means the new 20 amp LifePo4 charger would be trying to charge the lithium battery at the same time supplying 12V to the fridge. It would greatly diminish the charge going to the battery.

Or I could just turn off the circuit breaker for the WFCO converter, but I would end up in the same boat. The new LifePo4 would be trying to charge the lithium battery at the same time as supplying 12V to the RV.

We'll have to see how things work using both chargers at the same time.