Converting to dual Li time 200 AH batteries. I have a 2019 momentum toy hauler.

[Hoopy Frood]

I confirmed safe first. Here’s how I determined the circuit was definitely 20A capable. Although the receptacle was 15A configuration with parallel spades:

1. 20A breaker OEM
2. 12 Gauge wire
3. Receptacle had only one plug in. The other was blanked out.
4. Used VOM to confirm it was the only outlet on that circuit.

Since my new lithium 75A converter had a 20A configuration plug and the receptacle in the RV was 15A configuration, I had to either get an adapter or replace the receptacle. I was unable to find a single outlet 20A configuration receptacle that would fit existing setup and being aware that the only difference between a 20A and a 15A receptacle is the configuration of the face plate and that they are internally the same, I chose to get an adapter and keep everything else original. It did take me a bit to find a 20A capable adapter. Ended up being a pigtail. It looks really good too because everything ends up being original.

Was warranty the reason you didn't change the plug on the converter?

 

[coglesby]

Was warranty the reason you didn't change the plug on the converter?

That was part of it but I mostly just wanted to keep as much original as I could. It turned out to be a good thing because it is a WFCO auto detect and those things won’t stay in lithium mode. I contacted WFCO and they suggested to put a jumper in to lock it into lithium mode and they paid for shipping and didn’t charge me anything to do the work since it was under warranty. Woohoo

 

[poohbear]

I will say from my experience if it's a "dedicated " circuit the NEC does not allow useing a 15 amp receptacle on a 20 amp circuit. That would get you a red tag at inspection. Now it's been awhile since I needed to be up to date but I'm one that follows it's guidance whether my house or rv.
Heck, you can get a 20 amp duplex receptacle for $2.77 on Amazon & the single is $6.18

 

[coglesby]

I will say from my experience if it's a "dedicated " circuit the NEC does not allow useing a 15 amp receptacle on a 20 amp circuit. That would get you a red tag at inspection. Now it's been awhile since I needed to be up to date but I'm one that follows it's guidance whether my house or rv.
Heck, you can get a 20 amp duplex receptacle for $2.77 on Amazon & the single is $6.18

Yes, it’s strange that there are 3 cases of that by GD just within this thread and in one case they put a 20A sticker on a 15A style receptacle.

 

[coglesby]

Was warranty the reason you didn't change the plug on the converter?

Also, I don’t think that it would be safe to change out the plug. I assume WFCO put it on there for a valid reason but who knows. I read other posts where folks purchased a 125A converter and it had a 15A style plug on it. There are RVIA standards that GD claims to adhere to but I don’t know what the requirements are. Maybe other suppliers only sell after market so they don’t sell to RV manufacturers that follow RVIA standards but I have no idea.

 

[huntindog]

I will say from my experience if it's a "dedicated " circuit the NEC does not allow useing a 15 amp receptacle on a 20 amp circuit. That would get you a red tag at inspection. Now it's been awhile since I needed to be up to date but I'm one that follows it's guidance whether my house or rv.
Heck, you can get a 20 amp duplex receptacle for $2.77 on Amazon & the single is $6.18

I am not an electrician, but that is what I have been saying all along.
As a common sense matter it would make zero sense for a 15 amp receptacle to be wired to a 20 amp breaker.
Electricity is not an area I will cut corners on. The potential risk is just too great.

 

[coglesby]

The entire circuit in my GD is 20A so it is to code. What I don’t understand is why the 20A valterra receptacles that GD uses have a faceplate that is configured as a 15A receptacle so that a 20A appliance can’t be plugged into it. I was unable to find a valterra 20A receptacle that will accept a 20A plug. I don’t think there are 20A household receptacles that are configured that way but I could be wrong. My sticks and bricks has only 20A breakers and 15A receptacles but none are dedicated so it is possible a 15A receptacle could have more than 15 amp drawn without tripping the breaker. This is very likely if one uses a 15A to 30A dogbone but that doesn’t stop people from doing it and I bet many on this thread have.

 

[coglesby]

I sent an email to WFCO technical support asking why the WF7920 has a 20A receptacle that will not accept the 20A plug they put on the WF9875 converter. Let’s see what they say if they even respond.

 

[coglesby]

I am not an electrician, but that is what I have been saying all along.
As a common sense matter it would make zero sense for a 15 amp receptacle to be wired to a 20 amp breaker.
Electricity is not an area I will cut corners on. The potential risk is just too great.

You can rest easy. I had to go to Home Depot today to pick up some items to fix my leaky faucets so I picked up a low profile box and a simplex 20A receptacle and installed it today. Bonus is my wife is pleased about the faucet not leaking.

 

[coglesby]

I will say from my experience if it's a "dedicated " circuit the NEC does not allow useing a 15 amp receptacle on a 20 amp circuit. That would get you a red tag at inspection. Now it's been awhile since I needed to be up to date but I'm one that follows it's guidance whether my house or rv.
Heck, you can get a 20 amp duplex receptacle for $2.77 on Amazon & the single is $6.18

Do RV parks get away with it because it’s a duplex receptacle or are they always a 20A receptacle, I can’t remember.

 

[poohbear]

Do RV parks get away with it because it’s a duplex receptacle or are they always a 20A receptacle, I can’t remember.

If the installation was inspected/permitted then the receptacle "should" be the same amp rating as the breaker that is feeding the power pedestals 120 receptacle. Also it's considered a wet location so either GFCI receptacle or GFCI breaker.
Now if the power pedestal wasn't done where a permit is required , who knows how/what was done. In my state electrical is supposed to be done no matter by who using the current adopted NEC , here in Tx its the 2023 NEC, whether or not it's in a permit/inspection area . I live in a county that doesn't do any inspection/permit other than septic & water wells which is a state thing. Only a couple of towns have code enforcement in my county.
Back to the li battery. If I get only (2) 100AH Li batteries with 100amp BMS each I shouldn't have any trouble starting genny or slides/levelors with hydraulic pump ?

 

[coglesby]

If the installation was inspected/permitted then the receptacle "should" be the same amp rating as the breaker that is feeding the power pedestals 120 receptacle. Also it's considered a wet location so either GFCI receptacle or GFCI breaker.
Now if the power pedestal wasn't done where a permit is required , who knows how/what was done. In my state electrical is supposed to be done no matter by who using the current adopted NEC , here in Tx its the 2023 NEC, whether or not it's in a permit/inspection area . I live in a county that doesn't do any inspection/permit other than septic & water wells which is a state thing. Only a couple of towns have code enforcement in my county.
Back to the li battery. If I get only (2) 100AH Li batteries with 100amp BMS each I shouldn't have any trouble starting genny or slides/levelors with hydraulic pump ?

There’s a recent thread in this forum going on right now if you check main page. So we have two threads going on about LFP batteries

Just installed 100amp ht li time lithium battery, wondering about voltage?

Have a 2024 303 RLS camper, and just changed out battery to 100amp hr lithium battery. I have 380 watt solar on the roof. I changed out the charge controller a while back to MPPT 100/30 Victron from advice on here. As the one that came with the unit kept failing. I installed the battery 2 days...

www.mygrandrv.com

 

[triplethreat]

If the installation was inspected/permitted then the receptacle "should" be the same amp rating as the breaker that is feeding the power pedestals 120 receptacle. Also it's considered a wet location so either GFCI receptacle or GFCI breaker.
Now if the power pedestal wasn't done where a permit is required , who knows how/what was done. In my state electrical is supposed to be done no matter by who using the current adopted NEC , here in Tx its the 2023 NEC, whether or not it's in a permit/inspection area . I live in a county that doesn't do any inspection/permit other than septic & water wells which is a state thing. Only a couple of towns have code enforcement in my county.
Back to the li battery. If I get only (2) 100AH Li batteries with 100amp BMS each I shouldn't have any trouble starting genny or slides/levelors with hydraulic pump ?

As long as the batteries are capable ...AND...the BMS(s) are capable of providing 100 amps each, you should be OK. My current (no pun intended) setup is a 302AH battery, but I chose to use a 200A BMS when I built the battery/bms setup....and I've had zero issues. Functionally, two 100A batteries with two 100A BMS(s) hooked up in parallel should provide you with the same amount of current that I have available. Yes, on mine the battery is capable of more current, but is limited by the BMS.

 

[coglesby]

I sent an email to WFCO technical support asking why the WF7920 has a 20A receptacle that will not accept the 20A plug they put on the WF9875 converter. Let’s see what they say if they even respond.

Here’s the responses I got in case anyone wants to contact WFCO technical support to get help:

Get a picture of it and send it to me. I will see if I can find the receptacle and send it to you - - any idea on how long (Length) it needs to be?

I haven’t seen a WF-7920 in forever -
Thank you !

Regards,
Tim
WFCO Technologies
Technical Support
2021 Aeroplex Drive North
Elkhart, Indiana 46514
P: 574-294-8997 ext. 302

 

[TexasToyTrike]

Converting to 2 LiTime 12v 200AH “self heating” batteries rated for winter usage. Where do I find the charger at to see if it is compatible with the lithium batteries? Bought the 5th wheel used. Is this just a plug and play conversion?

Call or email WFCO and give them your current converter model #. They will give you the upgrade part #. Purchase from a reputable source (WFCO is cautioning customers from buying off of Amazon due to poor quality knockoffs) I ordered from Camping World.
The upgrade is a 15-20 min job. All you need is a couple of screw drivers. Then let your new Lithium cycle through regular charge and discharge cycles. The new auto detect will set itself.
Best of luck!

 

[poohbear]

I have learned a lot about doing the Li upgrade but after reading all I could on this and other forums I just went with 2 sealed LA batteries. I found out the converter is a plain wf9855 not an AD model so that was going to have to be replaced.
The real decision item came to my wife's health, took another nose dive so how much longer she can RV is just a guess . I don't see even 2 years so I'll just let the next owner use their money. we don't boondock so like I have said its really just to keep the fridge on during our regular 7 hr trip to NW Arkansas.