WFCO "Autodetect" charging issues

[turkington]

Hi folks, first post after reading and learning heaps here!

We have a camper with a modest 165W panel and a Furrion 25A MPPT solar controller going to a SOK 206Ah battery. In full sun this is great and allows us to dry camp and keep the 12v fridge going. Unfortunately, we live in the Pacific Northwest and cloudy/rainy days with lots of tree cover are more the norm so we need an alternate charging source every few days. While our Honda eu2200i is awesome and quiet, the stock WFCO 8735-AD appears to be the weak link...

The WFCO converter correctly detects the LiFePo battery (blue LED lit) and does go into bulk mode (charging at 25-30A with the red LED lit) **if the battery is almost dead** but most of the time it's in absorption mode at 13.6v and charges **very slowly** at 4-6A. WFCO's manual states that the converter will go into bulk mode at power up for a minimum of 1h and up to 4h depending on state of charge but I have never experienced this, short of when the battery was empty with the BMS disconnecting the cells in D-MOS mode.

If we're at say 50% SOC and it's a dreary day with no solar production, we're looking at a full 24 hours of generator time to recharge... not going to happen but at 30A a 3-4 hour run while still long may be feasible.

Short of some magic that I'm missing that the community can suggest I'm looking at replacing the WFCO with a Progressive Dynamics 4135 converter that's almost plug and play. My concern with this option is that the specs for it state that in LiFePO mode it outputs a constant 14.6v and doesn't switch into a lessor voltage mode.

Any help or suggestions greatly appreciated.

Jeff Turkington,
Whistler, Canada

 

[brb58]

You likely have a huge voltage drop between the converter and the battery. Measure the voltage at the converter and the battery when you first turn the converter on and it is still in bulk charge mode.

What size wire is between your converter and battery?

 

[turkington]

You likely have a huge voltage drop between the converter and the battery. Measure the voltage at the converter and the battery when you first turn the converter on and it is still in bulk charge mode.

What size wire is between your converter and battery?

I haven't pulled everything out yet but it looks like 15 feet or so of #6 copper for the positive and the frame for a ground return.

 

[time2roll]

I would stick with the non-lithium Progressive Dynamics converter. Better profile, manual control with the Wizard button.

With #6 wire move up to 45 or 60 amps.

 

[brb58]

I haven't pulled everything out yet but it looks like 15 feet or so of #6 copper for the positive and the frame for a ground return.

That's way better than most. I would still do a voltage check.

How are you measuring current?

 

[turkington]

That's way better than most. I would still do a voltage check.

How are you measuring current?

Will do when I have everything apart on Monday I have a Victron 712 shunt near the battery on the negative lead.

 

[brb58]

Will do when I have everything apart on Monday I have a Victron 712 shunt near the battery on the negative lead.

perfect...even with 6AWG wire if it was 15 feet one direction and 15 feet for ground(I know you have the trailer frame) you could easily have 0.5V drop. That will drop you out of bulk faster than you want. I know many people that up grade that wire to a lot bigger wire. Just becuase a wire is rated to carry a certain amount of current doesn't mean the voltage drop isn't going to be an issue..especially with these converters. Sure wish they had a remote voltage sense option.

I actually moved my converter next to my batteries. I do have that Progressive lithium charger that keeps them at 14.6V. I just turn my battery switch off when I am on shorepower so the battery doesn't see the converter. I actually rarely use my converter since I almost always drycamp.

 

[turkington]

perfect...even with 6AWG wire if it was 15 feet one direction and 15 feet for ground(I know you have the trailer frame) you could easily have 0.5V drop. That will drop you out of bulk faster than you want. I know many people that up grade that wire to a lot bigger wire. Just becuase a wire is rated to carry a certain amount of current doesn't mean the voltage drop isn't going to be an issue..especially with these converters. Sure wish they had a remote voltage sense option.

I actually moved my converter next to my batteries. I do have that Progressive lithium charger that keeps them at 14.6V. I just turn my battery switch off when I am on shorepower so the battery doesn't see the converter. I actually rarely use my converter since I almost always drycamp.

Trying not to be a total noob here, but is there an issue with constant 14.6v at the battery? Won't the BMS disconnect when the cells are fully charged? Or is this being too reliant on the BMS for protection/charge management and a two stage 14.6/13.6v charger the more wise option?

 

[brb58]

Better if your battery doesn't just sit for long times at the BMS cutoff voltage or above. I used to allow that to happen...now I just make sure my batteries are disconnected when on shorepower.

Progressive is actually changing their lithium converter so it doesn't do that anymore.

 

[TacomaJoe]

In my rig, I kept the WFCO converter and instead purchased an AIMS 75A charger that I put next to the battery. It is only run with the generator to make up for lack of sun (also in PNW). Keeps generator time down.

 

[turkington]

In my rig, I kept the WFCO converter and instead purchased an AIMS 75A charger that I put next to the battery. It is only run with the generator to make up for lack of sun (also in PNW). Keeps generator time down.

Exactly, with the PD 4135 charger having only one profile and being slightly smaller by 1/2" it's not ideal... Looking at a Victron 30A charger that I can also put in the passthrough next to the battery and have ultimate control over charging and future integration with other Victron components.

 

[turkington]

**Problem Solved**

I neutered the WFCO 8735 by disconnecting the AC input and adding a Victron IP22 30A charger in the pass-through near to the LiFePO battery. This charger connects over Bluetooth to the Victron Smart Shunt to read voltage/current at the battery and is configurable up the wazoo! Now when the battery is discharged, even slightly it goes into bulk mode at 30A until the absorption voltage of 14.6 is reached and then stays there for 15 min until going into storage mode at 13.8v.

In hindsight this was a no-brainer but I have to admit I was focused on making the WFCO or Progressive Dynamics products work...

Thanks for all your input folks!

 

[Taxus812]

I know you already solved your problem. I just spent my camping trip figuring out this thing and wanted to share for someone else pulling their hair out.

If it “sees” a full battery and goes into float, You can fake the controller out and force it out into bulk mode by throwing a big load on while charging. I have the 8955 AD so i threw a bunch of fans on. It kicked into bulk mode after a few min. Then I shut off the load and it stayed in bulk until it was done charging. Without doing that it stayed at 10-12 amps.

I think it is a leftover from the Lead acid program where if the converter sees more than half of its rated current rating being drawn it kicks into bulk. (Weird part is the Renogy battery should do that).

 

[turkington]

I know you already solved your problem. I just spent my camping trip figuring out this thing and wanted to share for someone else pulling their hair out.

If it “sees” a full battery and goes into float, You can fake the controller out and force it out into bulk mode by throwing a big load on while charging. I have the 8955 AD so i threw a bunch of fans on. It kicked into bulk mode after a few min. Then I shut off the load and it stayed in bulk until it was done charging. Without doing that it stayed at 10-12 amps.

I think it is a leftover from the Lead acid program where if the converter sees more than half of its rated current rating being drawn it kicks into bulk. (Weird part is the Renogy battery should do that).

Thanks, I tried that several times with no change and even looked at the hacks for the sense level input but the controller board had changed and it was turning into a waste of time. The Victron integration (over the local Bluetooth network) between charger and shunt is awesome and effectively a modern version of sense wires.

 

[Chaucer]

**Problem Solved**

I neutered the WFCO 8735 by disconnecting the AC input and adding a Victron IP22 30A charger in the pass-through near to the LiFePO battery. This charger connects over Bluetooth to the Victron Smart Shunt to read voltage/current at the battery and is configurable up the wazoo! Now when the battery is discharged, even slightly it goes into bulk mode at 30A until the absorption voltage of 14.6 is reached and then stays there for 15 min until going into storage mode at 13.8v.

In hindsight this was a no-brainer but I have to admit I was focused on making the WFCO or Progressive Dynamics products work...

Thanks for all your input folks!

Hi @turkington

Old thread but have a question.

When you disconnected the AC input, didn't that also remove power to the 12V circuits since it's a combo converter/charger that cna't be seperated.

 

[scrubjaysnest]

The WFCO OUTPUT is a red and black wire connected to the dc distribution system. You remove those and wire the IP 22 output in their place. From the distribution system another pair of wires go to the battery bank maybe thru an isolation relay.

 

[Chaucer]

Hi,

So, I'm clear you remove the wires circled in the picture and connect the IP22 output there?

That will charge the batteries and run the 12V circuits? Correct

Tks

 

[scrubjaysnest]

Yes, if the red and white wires go to the WFCO. Also there should be another pair that go to the battery bank. Sometimes the positive wire goes to an isolation relay that is operated by a use/store switch.
Always label each wire and verify were it physically goes prior to removal.

Edit: a closer look at the board makes me think the WFCO ÷ and - wires have already been removed. If so the red and white go to the battery bank. If that is the case the negative wire from the Victron goes to the terminal with the white wire and the Victron plus goes to the terminal with no wires on it if I remember correctly. I don't have a WFCO distribution panel in front of me to look at.

 

[Chaucer]

The circled wires (red and white) in the photo go to the charge/converter. That photo is from a WFCO video that is taken apart.

There is a red wire on the #6 fuse that goes to the battery bank.