Updating Your Power Center for LiFePo4: WFCO or Progressive Dynamics?

The_Rigger

So I think most of us can agree that upgrading your T@G electrics from lead-acid to LiFePo4 is pretty much the way to go, with respect to power density & tongue weight reduction. What I'm thinking about today is updating my trailer's power center to maximize the benefits of those lovely lithium-iron batteries. I see two potential courses of action in my future, with respect to replacing the old-school WFCO WF-8725:

A.) a newer WFCO WF-8725-AD that auto-detects the battery type (or is supposed to, anyway) and is capable of LiFePo4-level charging
B.) a Progressive Dynamics 4100-series, probably the 4135, which is manually switched between lead-acid/AGM and LiFePo4

Pros/Cons:

The new WFCO will certainly fit in the same hole in the coachwork as the existing power center. The PD would require minor carpentry to open up the WFCO's mounting hole but hardly by much, and it's definitely not too deep to fit in the bulkhead.

Wiring both units would be dreadfully easy, however the edge (and it's a small edge) goes to the WFCO, only because it would be a direct swap, matching color codes.

The AC breakers would be a direct swap over to a new WFCO. I'm not sure if they will fit the PD, however I do know what series of tandem breakers do fit it, so all I need to do is look at what make & model my current ones are in my old WFCO. It would certainly be nice if they did fit the PD, as tandem breakers aren't exactly dime-a-dozen.

The PD4135 would give me two additional fused DC circuits over the WFCO (the PD has six DC circuits to the WFCO's four), so I could fuse my added fridge power line at the power center, rather than having an inline fuse in the power cable.

The PD has a microswitch on the panel to select between AGM/lead-acid and lithium-iron operations. It's kinda hard (albeit not impossible) to screw that up. I have no evidence that WFCO's auto-detection system fails to work, however... Well... You know... Nothing's completely foolproof. I've learned through hard experience that if anything can go wrong, eventually it WILL go wrong.

Anyway, has anyone here had any first-hand experience with the PD4100 series? How'd ya like it? I know they're built about an hour south of me, here in Michigan, and I'd be lying if I didn't admit that has a tiny effect on me...

zgfiredude

I can say that I just did an install of a WFCO/AD in my son's teardrop of a different brand. It fit the space perfectly as you suggest, and everything works perfectly. The wiring swap is pretty easy although tedious when you have ADD like me, LOL.

toadzurg

I installed a Renogy smart LiFePo4 (Bluetooth) in my 2018 T@G, replacing the stock lead acid. It actually works pretty well with the original power center. Its smart enough to not over/under (dis)charge and charges at ~8amps, gradually reducing from 8-7-6-5, etc.. up until 80% then trickle charges at 2-3 amps. Only downside is sometimes it will stop at 95-98% unless there is a small load on the battery then it will continue charging to 100%. It might be better for the battery not to get to 100% anyway. Just my experience

Sharon_is_SAM

@The_Rigger - there has been a lot of discussion regarding the automatic detection on the WFCO power center over on the TaB forum. It doesn’t always work. I believe instead of changing out the power centers, some owners elect to use solar with a lithium enabled controller and/or a lithium specific battery charger (NOCO) to fully charge their lithium batteries.

https://tab-rv.vanillacommunity.com/discussion/16210/wfco-wf-8735-ad-lifepo4-fyi-on-annoying-auto-detect-quirk/p1

The_Rigger

@Sharon_is-SAM - That was interesting reading, and pretty much what I was afraid of...

If I could find a new-old-stock WF-8725LiS gathering dust on a shelf somewhere, that would be a perfect solution - the ease of swapping WFCOs coupled with the lack of an auto-detect system that may or may not be quite ready for Prime Time. Just flip a switch to the Li position and put it out of mind. In the absence of an 8725LiS, I think I'm gonna go with the Power Dynamics unit, just for the peace-of-mind. Having the extra two 12VDC circuits is an added bonus.

(EDIT: I think I may have a line on an actual NOS WF-8725LiS from a dealer in Washington. Stay tuned...)

Sharon_is_SAM

Sweet! Best of both worlds!

The_Rigger

In other news, I ordered one of these today:
https://www.timeusbpower.com/products/100ahpro

The_Rigger

Progress report: I have indeed managed to track down a pre-AutoDetect version of the WFCO power center that has a manual switch for shifting the charging profile between lead-acid and lithium-iron phosphate batteries (think: hen's teeth)...

I've also taken delivery of a TimeUSB 100Ah Pro lithium-iron battery. Just for giggles, I got out the bathroom scale and compared it to the OEM flooded battery as equipped from nüCamp... Dear lord!! 41 lbs for the Interstate vs 23 lbs for the TimeUSB cell.

The only issue, if you want to call it that, is that the new cell is a Group 31 size while the old lead-acid anchor is a Group 24, so I had to pop for a new battery box. Fortunately Camping World has a suitable Camco box on sale for half price. I'll also need to replace the existing ring terminals on all the battery wires with slightly smaller ring terminals, as the new lithium cell uses 6mm bolts, while the Interstate cell uses 3/8" studs, so I'll have to replace the OEM 7/16" ring terminals with 5/16" rings. I'll get over it, I'm sure...

The_Rigger

WF-8725LiS arrived today. If anyone else is considering converting to LiFePo4 battery bank, and would also prefer to change their power center to a lithium-capable model, there are still a few new-old-stock WFCO switched-lithium models available on eBay for decent prices. That way you don't have to risk WFCO's not-ready-for-Prime-Time auto-detection circuitry. Search for "WF-8725-PB-LIS".

toadzurg

How difficult is it to swap to a WF-8725-PB-LIS?

The_Rigger

It should be a piece of cake. The LiS is virtually identical to the existing WFCO Power Center, the only differences are internal. I should think the hardest part will be doing the AC wiring; the DC part is literally matching wire colors.

EDIT: I'll be able to tell you for certain after Thursday; that's my next day off and I'm planning on doing the swap that morning.

rich67

I installed a LiFePo4 in my Tag a couple years ago, retaining the original solar controller with my NuCamp installed solar panel. I only had to change some settings on the Victron app to maximize usage and charging properties. Was traveling all year last year in the camper and got a good 5 days of power from it even when it was slightly overcast out. That's with running the lights occasionally, fridge set to 37, watching TV at night for a couple hours, and using the fantastic fan at night....all night. So I don't see the need to overthink and do all the fancy upgrades. Just throw a battery in the tray (I spent about 400 bucks for it off Amazon) and tweak the Victron setting and go. If you don't use the fan and TV and have an ice cooler, you should easily squeeze over a week out of it or more.

The_Rigger

I live in Michigan, which is where I do 99% of my camping. Relying on the solar panels isn't really a viable option here - you can tell who the transplanted Michiganders are in Seattle, cuz they're the ones walking around commenting on the sunny weather.

I offer this as an alternative to the less-than-dependable auto-detect system that WFCO is currently selling. Folks are, of course, free to do what they wish with their own campers... But so am I.

The_Rigger

Well... I swapped WFCOs today, and it was a touch more of a pain than I expected, because of the way the AC side was wired. But the deed is done, and now according to my trusty Fluke multimeter, the charger output to the LiFePo4 battery is a solid 14.6VDC in Bulk mode and 13.6VDC in Absorption mode, with no equalization mode at all to worry about... Just what the lithium battery loves.
Part of the fun was due to the camper being parked in the winter storage yard, with no AC power anywhere near it, so I had to drag my generator over there to run my soldering iron & heat gun for the heat-shrink tubing, plus have a reliable 125V 30A service to test the finished job. It's also not the most convenient or comfortable position to be in for working on anything, sitting inside on the floor for an hour or two with my arthritic knees jammed into the bulkhead wall.

Here are the two power centers at the beginning of the adventure.

Wires-Я-Us.

The Finished Product. Note the two amber LEDs lit up on either side of the battery switch at the top of the DC fuse board; those indicate the unit is set up for LiFePo4 batteries and is charging in the higher Bulk mode; when the LED on the right side of the switch goes out, the charger has dropped into the 13.6VDC Absorption mode.

bog

great work, what model of WFCO did you have before switching?

The_Rigger

https://teardrop-trailers.vanillacommunity.com/discussion/comment/13255#Comment_13255

I had the bog-standard WF-8725.

zgfiredude

@The_Rigger do you have any updates/comments on how the system is working? I'm heading this direction as well.

The_Rigger

@zgfiredude said:
@The_Rigger do you have any updates/comments on how the system is working? I'm heading this direction as well.

Not really; I didn't have very much time with the updated system before having to put the camper to bed for the winter. I did a couple of nights' camping with the new stuff and it all functioned perfectly (so far), and I could definitely feel the difference in tongue weight between the old lead-acid battery and the new TimeUSB lithium-iron cell. But more testing & tweaking will have to wait 'til springtime. I was able to get the basic parameters reset in the VictronConnect solar controller for the LiFePo4 cell, but I'm sure there are more settings that I need to futz around with to fully optimize that part of the electrics.

As for the AC side of the new power center, I did hook the camper up to my generator (a Generac GP3000i, which I heartily endorse and recommend if you're in the market for quiet, stable portable power and don't have $2500 to drop on a Honda unit) and again, perfect operation and no surprises. Or almost none, at any rate...

The only "surprise," I should say, was how the AC side of the WFCO was wired up when it was originally installed in the new T@G construction; the Reader's Digest Simplified Version was that the 30A breaker #1 in the WFCO is in essence wired up backward, with the AC hot input wire connected to the main breaker output, rather than the + bus bar. I can see why it was done that way — if you hook the + wire to the bus bar, you don't really have a main breaker in the panel. Instead you have four individually breakered branch circuits. By backfeeding the 30A breaker, electric power is fed to the AC bus through the 30A breaker, which gives you Main Breaker protection for the entire AC bus, along with three individual protected circuits, and all it costs you is the possibility of a fourth branch circuit. It's kinda weird, but it works.

Anyhoo... The battery is currently tucked under the workbench in my storeroom (along with mattresses & linens & other stuff from the T@G that I don't want frozen and winter-damaged) and staying warm, unlike the camper which is under cover outside in a nearby storage lot. Soon as the weather breaks this spring, I'll haul her back home, reload everything, and finish all the dialing-in of various aspects of the electrics. But for right now I'm pretty happy with how it's turning out.

To be continued...

zgfiredude

Thanks very much for the reply!

Kfitz

Could an electrically challenged person, like me, do the swap as you did? The AC part sounds like a difficult process not knowing much about electric.

zgfiredude

All you really need to do is make sure the trailer has NO power....so battery is disconnected, and it's not plugged into shore power. Then you pull out the power center and take pics on your phone of the back side. Then you just replace wires one at a time. It's doable in my opinion...it's a little tedious, but not "hard".

The_Rigger

https://teardrop-trailers.vanillacommunity.com/discussion/comment/13334#Comment_13334

In theory yes, you could do the swap. Be aware that it'll most likely take more time than you think it will, because of your skill level. Take your time, take LOTS AND LOTS of pictures for reference (and maybe even sketch a drawing or two) as you progress through the job, and triple-check every step of the way. And be ready to ask for help from someone who is knowledgeable in the ways of the electron...

The way the AC side was wired is definitely non-standard, but it's not terribly hard to do, aside from wrestling stiff wires into tiny places. Take your time and check your work, preferably BEFORE you power up the system, and you should do fine.

Also, be sure to note that the Absolutest Firstest Step #1 on a power center swap is COMPLETELY DISCONNECT THE BATTERY (BOTH POSITIVE AND NEGATIVE CABLES) AND ALL AC POWER SOURCES FROM THE TRAILER BEFORE YOU BEGIN!!! When in doubt, refer to the Absolutest Firstest Step #1. DO NOT rely on the battery switch to isolate the WFCO from the battery; you'll risk still getting power back-fed from your solar array.

Nobody is born knowing anything about electricity; not even me. Taking on jobs like this is how one learns... And while a WFCO power center swap may not teach you much about AC or DC electric theory, it'll certainly serve to build confidence in your abilities & give you some valuable experience in your wiring & camper maintenance skills. It's not a walk in the park by any means, but in the Grand Scheme of Things, it's not a horribly complicated project.

normaandchris

Hello @The_Rigger.
Would you be willing to help out a picture-challenged individual? I was swapping out my standard WFCO 8725 for an AD version in my T@G and apparently did not take enough pictures. My wiring looks exactly like your second picture above.
I am having difficulty with hooking up the shore power wiring (all the 12V stuff didn't kick my butt). Do you by chance have some extra pictures you'd be willing to share?
My panel has 4 sets of shore power wiring - 1 white sheathed, 1 orange, and 2 yellow. I have the yellow correctly installed to the 2 20A circuit breakers. The orange is hooked up to the 15A.
My real difficulty is that hot (black) wire from the white sheathed cable pack. IIRC correctly, this should be the shore power feed to the whole panel, but I cannot recall where or how or to what other wiring it was connected.
Any assistance would be greatly appreciated folks.

normaandchris

On further review, I believe I figured it out after rereading the above and looking at my set-up again. The converter came with a hot lead wired on to the busbar for the breakers. Removed that (3mm allen - wth when all others are Philips or square drive?) and connected it up. Will test w/the battery tomorrow; had to get out of the cramped quarters and stretch out a bit.

The_Rigger

Hi @normaandchris,
Sorry I hadn't gotten back to you until now; life got in the way.

I don't have any more photos of the wire work, but it sounds like you got it sorted out without 'em. Like I said in my longer description, my WFCO was definitely wired up in an unorthodox manner, but the end result was that the 30A breaker in slot #1 does in fact protect the entire AC side of the power center, including the AC-to-DC converter, whereas connecting the incoming shore power hot wire directly to the bus bar instead of backfeeding through the breaker would have given me a fourth AC circuit (un-needed) but would've left the power center main feed unprotected. It's not exactly the way I would've expected nüCamp to wire the thing up, but it does the job.

I'm not sure I'd recommend anyone else wire theirs up in the same way, and frankly I'm not sure I'm going to leave mine wired in this manner.