WFCO converter conversion to 8735-AD

[huntindog]

I vote for the Powermax. I removed my OEM model and replaced mine with the 120A Lithium version for my 560 aH LiPO4 battery pack. There is no dance involved or funny business. It gets busy when the shore power is active or the generator is plugged in. I don't have to drain the batteries to a certain amount nor do anything else to get it to charge. It just works. I moved it to my front compartment so my battery leads are short and I have it on a bypass switch in case I want to isolate it from the system.

I had a Powermax in my last TT. It worked well, but was less refined I guess than a PD. When it shifted modes, it would pause charging for a second or two. Since I got it to replace a WFCO that never changed modes, I sorta liked that pause... It was proof it was working when the lights dimmed for a second. None of my PDs had such a pause. That powermax failed after 8 years of heavy use, and I was ready to sell that TT, so I put the WFCO back in it.

[sutrick2001]

Just for a follow up, I opted for the Powermax. I installed it in the fron pass through and left the stock WFCO converter in place. I was able to get 14.4v @ 50 amp off 1) an extension cord plugged into the pedestal while my 30 amp cord was plugged into shore power. 2) plugged the converter into the 110 outlet in the pass through while connected to shore power via the 30 amp cord, 3) via a 110 extension cord from the generator, and 4) from the pass through outlet with the 30 amp cord connected to the generator.

Overall pretty happy so far, this is our first camper and I know we will be upgrading in a couple years so I didn't want to drop a bunch of dough in upgrades. We went mostly Renogy on this upgrade, will most likely go Victron on next camper. There is a fine line between getting an all in one and piece mealing it all together. Next upgrade will be to add more solar.

Thanks every one.

[FL-Guy]

I have the 8735-AD on my TT. Just switched to a 200Ah LifePO4 battery. I ran the battery down to about 11.2V as suggested to try and get the converter to switch to lithium mode, but it wouldn't switch for me. I call WFCO tech support and was surprised that I got in touch with someone on the 2nd ring. The tech told me sometimes it takes a second restart once the board goes into bulk charging mode (red LED) before it will switch. Bingo. Second restart and the green LED turned to blue.
The tech told me there is an older version of the software on some of the boards that can be updated, but you have to send the unit in to have them flash it (covered under warranty) Supposedly there is a label inside the door cover of the panel with a version number sticker on it. I couldn't find it on mine but was happy that the unit switched and I didn't have to pull it out. He said if I sent it in they could put a jumper on the board to keep it in lithium mode if I wanted them to. Hinted that they were developing a kit for that, so maybe a permanent fix is coming. Of course, what's the point of auto detect then?
He also mentioned that these units have trouble switching if there is more than 15 ft of wire between the converter and the battery. My 17ft MKE has more than 15' of wire for that run because the converter is in the back of the trailer and the wires cross from the back passenger side (converter) to the front driver side behind the wet wall in the passthrough, then across the trailer to the busbar on the passenger side of the tongue, then to the battery. I saw that when I dropped the coloroplast to reroute the wires inside under my Murphy bed where I put the battery.

Anyway, I'm in lithium mode and my 200Ah battery is charged to 205Ah (reviewers of my battery on Youtube have shown it actually has 220-230 Ah) and it reads 100% on my battery monitor. I did only take the battery down to 11.2V before zeroing the Furrion battery monitor so I assume the 205 is actually higher.

[Trapper]

I have the 8735-AD also on my 2022 22mle and have added 100Ah lithium and no go on the auto detect working. I have spoken to the WFCO techs two times now and pretty much the same story. First unhook solar, run the battery down low (10% both times), change out the fuse to a 40amp in the box and on the frame by the battery. I am on my second try through this process because I had not switched out the fuses. I highly doubt that will make a difference and only cost $5 for the frame fuse and I had a 40amp panel one.. This was Shawn's recommendation from WFCO and he was sure this would do the trick, we will see, I am not holding my breath lol They didn't tell me to but I also shut off the 12v fridge so nothing would be interfering with the charge.
I was thinking if it is the distance issue then why not move the charger to the front, there are only 4 wires. I may be way off in my thinking because I am not an electrician or engineer. I doubt it could be that simple, and I don't mean in terms of running the wires up to the front and relocating but in the fact it is really just a distance issue.
What might someone who understands think?
I know it is probably easier to just put it in the bench or passthrough with a lithium charger and turn the breaker off from the control panel or buy their $240 lithium charger.

[Dale B]

I have the 8735-AD also on my 2022 22mle and have added 100Ah lithium and no go on the auto detect working. I have spoken to the WFCO techs two times now and pretty much the same story. First unhook solar, run the battery down low (10% both times), change out the fuse to a 40amp in the box and on the frame by the battery. I am on my second try through this process because I had not switched out the fuses. I highly doubt that will make a difference and only cost $5 for the frame fuse and I had a 40amp panel one.. This was Shawn's recommendation from WFCO and he was sure this would do the trick, we will see, I am not holding my breath lol They didn't tell me to but I also shut off the 12v fridge so nothing would be interfering with the charge.
I was thinking if it is the distance issue then why not move the charger to the front, there are only 4 wires. I may be way off in my thinking because I am not an electrician or engineer. I doubt it could be that simple, and I don't mean in terms of running the wires up to the front and relocating but in the fact it is really just a distance issue.
What might someone who understands think?
I know it is probably easier to just put it in the bench or passthrough with a lithium charger and turn the breaker off from the control panel or buy their $240 lithium charger.

I do not remember the process, there is something about when the lithium battery is fully discharged you need to unplug the converter. Then when you plug back in & start the charge process the light will change to Blue indicating lithium mode. There is video demonstrating the process, I can find it if you need.

My batteries were disconnected over the winter, the other day I needed to empty the tanks. So I switched on the inverter to run the second even bigger POS Norcold junk fridge. My 2ea 200ah lithium batteries discharge to 50% after several hours. When plugged back into shore power I monitored the charge current from the POS WEFCO 8735 AD converter. It provided full charge current until the batteries were back 100%, it worked as described & stayed in Lithium mode.

[Trapper]

Yeah I have tried everything and for me I think it is the distance and may just move the battery closer.

[Fivecodys]

Yeah I have tried everything and for me I think it is the distance and may just move the battery closer.

Originally I has posted to this thread that mine was fine but further efforts showed that it was not fine. After a few calls and emails, WFCO had me send it back to them and they installed a 'firmware' update and then gave me the option to run a 'jumper' to permanently place it in Li mode. I opted for this and I received it back last week. After installation I was able to verify that the converter was putting out 14.4 volts. The best I was able to measure before was 13.6 volts.
They paid for shipping both directions. I took 3 weeks total.
Did they not mention this option when you talked to them?
BTW, my battery is 12 feet from the converter/charger.

I made a short YT video on this process.

https://youtu.be/R8xX2Nr6TzU

[Trapper]

Originally I has posted to this thread that mine was fine but further efforts showed that it was not fine. After a few calls and emails, WFCO had me send it back to them and they installed a 'firmware' update and then gave me the option to run a 'jumper' to permanently place it in Li mode. I opted for this and I received it back last week. After installation I was able to verify that the converter was putting out 14.4 volts. The best I was able to measure before was 13.6 volts.
They paid for shipping both directions. I took 3 weeks total.
Did they not mention this option when you talked to them?
BTW, my battery is 12 feet from the converter/charger.

I made a short YT video on this process.

https://youtu.be/R8xX2Nr6TzU

Thank you for replying.
Yes it took me 3 calls to get them to that point, after I jumped through all their hoops.
I am going to be close the their office next weekend and going to try and get setup to go in on either Friday afternoon or Monday.
Was told to call Larry on Tuesday because he has been on vacation.
I am going to try and move the battery closer in the next few days and see if that works.
Wish I had tried this while still under warranty with Grand Design and just made them fix it, but I can handle it.
Just so limited with my time right now. Thanks for the link I will check it out.

[Fivecodys]

Thank you for replying.
Yes it took me 3 calls to get them to that point, after I jumped through all their hoops.
I am going to be close the their office next weekend and going to try and get setup to go in on either Friday afternoon or Monday.
Was told to call Larry on Tuesday because he has been on vacation.
I am going to try and move the battery closer in the next few days and see if that works.
Wish I had tried this while still under warranty with Grand Design and just made them fix it, but I can handle it.
Just so limited with my time right now. Thanks for the link I will check it out.

Larry is who I dealt with. Real nice guy. Hopefully he will be able fix your issues.

Safe travels!

[BoredWeasel]

Dear Grand Designs,

As a new owner I am suffering, as those who have gone before me, with the Non-working Lithium Auto detect. I have the wfco 8735 AD and cannot get it to maintain the lithium mode and it is a real PIA to get it to redetect the batterys every time this happens.

First the battery is more than 10 feet from the charger, secondly the wire to the battery from the charger is maxed out if it is charging at 40 amps. No wonder it doesn't work. I suspect that a partially discharged battery looks like a nearly full agm to the wfco charger......

Please select a different battery charger for future models, something with a simple switch would be a huge improvement.

Thx