WFCO WF-8955PEC conversion to LiFePO4 charger

[Ged13]

My RV has WFCO-8955PEC converter, it's for lead acid batteries, therefore I need to replace converter as my LiFePO4 batteries coming this week.

Multiple people in forums around here are reporting constant problems with WF-8955-AD converter and recommendation was instead go with Progressive Dynamics PD4655V, however there are quite a few forums that also report PD4655V does not charge fast off shore power and/or generator. My unit has built in Onan 30A generator and would like to be able to be able to charge at full capacity a battery bank with total capacity of 608Ah (8xLF304 304Ah 3.2V LiFePO4 batteries).

Looking for recommendations - to get new lithium converter + inverter vs all-in-one Victron Multiplus it is double the price; is it that much better too?

1. Upgrade WFCO-8955PEC with:
   • 55Amp Lithium converter PD4655V (~$300 upgrade) OR add Victron Orion (~$300) to converter side (not even sure if that is a good option found https://diysolarforum.com/threads/wfco-charger-converter-to-victron.37596/post-480885 but this is only for DC side; not for battery charging)
   • Buy good quality 2000W inverter (~$300) - sadly I can't find any good inverters Renogy 2000W or Will's recommended GIANDEL 2200W Pure Sine Wave Power Inverter don't have that great of reviews)
2. Leave WFCO-8955PEC as is:
   • Install "Victron 12v Multiplus Compact 2000w Inverter 80A Battery Charger 120v" (~$1200)
   • Disconnect WFCO-8955PEC converter side (this is another topic - what needs to be disconnected, I think that Victron would go to batteries directly; but existing WFCO converter would continue to power existing 12v circuits e.g. lights, usb ports, fans)

Thank you for any help and your recommendations.

 

[sunshine_eggo]

My RV has WFCO-8955PEC converter, it's for lead acid batteries, therefore I need to replace converter as my LiFePO4 batteries coming this week.

This logic is only accurate as stated if you are selling converters and you wish to convince someone to buy one. It is not true unless the converter is determined to be inappropriate based on its specifications and use case.

WF-8955 Power Center - WFCO Electronics POWER CENTERS

WF-8955 Power Center – Output: 55 amps dc – Input: 105-130 V ac, 60 Hz, 940 W. 55 Amp Power Center. For lithium ready solution click here. - POWER CENTERS https://wfcoelectronics.com/product/wf-8955-power-center-3/ WF-8955 Power Center WFCO Electronics WF-8955

wfcoelectronics.com

Indicates:
14.4V bulk
13.6V absorption
13.2V float

The above is perfectly fine for LFP. The ONLY reason to replace it is if you plan a lot of generator charging. Due to the marginal wiring in most RVs, there will be an excessive voltage drop, so the unit will "see" 14.4V prematurely and drop to 13.6V thus cutting current and slowing charge. It can readily get your battery to 95%+ SoC on shore power.

The voltage drop issue can be a problem even for "LFP" chargers as they will taper current - they just hold 14.4V longer.

Multiple people in forums around here are reporting constant problems with WF-8955-AD converter and recommendation was instead go with Progressive Dynamics PD4655V, however there are quite a few forums that also report PD4655V does not charge fast off shore power and/or generator. My unit has built in Onan 30A generator and would like to be able to be able to charge at full capacity a battery bank with total capacity of 608Ah (8xLF304 304Ah 3.2V LiFePO4 batteries).

30A generator refers to the 120V side, so 3600W. A 55A converter is only going to charge at 55*14.4*1.15 = 917W

Looking for recommendations - to get new lithium converter + inverter vs all-in-one Victron Multiplus it is double the price; is it that much better too?

1. Upgrade WFCO-8955PEC with:
   • 55Amp Lithium converter PD4655V (~$300 upgrade) OR add Victron Orion (~$300) to converter side (not even sure if that is a good option)
   • Buy good quality 2000W inverter (~$300) - sadly I can't find any good inverters Renogy 2000W or Will's recommended GIANDEL 2200W Pure Sine Wave Power Inverter don't have that great of reviews)

If your goal is to "charge at full capacity" a 55A charger falls short. If you plan to use the other 2700W of generator for AC items, then that makes sense, but if you want to minimize run time and maximize charge rate, 55A isn't going to cut it.

To charge from 50%, 608Ah/55A = 11 hours of generator run time.

1. Leave WFCO-8955PEC as is:
   • Install "Victron 12v Multiplus Compact 2000w Inverter 80A Battery Charger 120v" (~$1200)
   • Disconnect WFCO-8955PEC converter side (this is another topic - what needs to be disconnected, I think that Victron would go to batteries directly; but existing WFCO converter would continue to power existing 12v circuits e.g. lights, usb ports, fans)

Thank you for any help and your recommendations.

With the above solution, you could power the WFCO with the AC-out 2 of the MP, which is only active if AC input is live, i.e., This would give you 135A of charging between the two.

You could also get another converter like a PM3-100LK, place it right next to the battery with thick cables and get 120A for $300.

 

[time2roll]

Well 55 amps into 608 AH is going to be 12+ hours working as designed. Not a fault of the converter. Need a rating about 200 amps to get the 3 hour recharge you might be looking for. Even the 80 amps of Victron charging could be considered weak. Actually there is a deck mount PD converter that goes 80 amps... if that is not fast enough get a second. 160 amps would about max out the generator.

One of the biggest issues with converters is the OEM 25'+ distance of #6 wire adds resistance, cuts voltage at max output and slows the charging. The inverter-charger generally has the advantage of being remounted close to the battery with short fat wire. Also the voltage can be adjusted to fit the need perfectly. Converter can be given this same advantage.

https://www.bestconverter.com/PD-9280C-80-Amp-RV-ConverterCharger

https://powermaxconverters.com/product/pm3-12v-series/

All "lithium" converters are charging at the absolute max 14.6 volts and is actually higher than necessary and may stress the battery more than needed. Some lithium converters just hold the 14.6 continuous and is hard on the battery. Standard PD is good and the PM3 will also serve well.

For a stand alone inverter I have and recommend the Go Power 2000w sine wave. The Multiplus is especially good if the generator is a bit undersize as it will combine power to meet temporary high loads and help with surge performance that could overload the smallish generator. Not an issue with the on-board generator as stated.

 

[Ged13]

That's some great info @sunshine_eggo and @time2roll. I guess I was reading "coolaid news" on "you must replace your converter".

@sunshine_eggo

30A generator refers to the 120V side, so 3600W. A 55A converter is only going to charge at 55*14.4*1.15 = 917W

what is the 1.15 in this line?


@time2roll

Go Power 2000w sine wave.

is this the model number: GP-ISW2000-12 that you recommend? This is more than double the price vs e.g. GIANDEL 2200W inverter; what makes it worth double the price?

Now that I got straightened up with some factual data; I am thinking to focus on solar install.

1. Keep WFCO-8955PEC as is; leave existing 55Amp converter as is. I will check the wire size between the battery and converter and upgrade to thicker wire if needed. Since I am relocating batteries; they will be about 5' of cable length away.
2. In mid-west where I camp; many days are 100F+; normally we run AC for 3-4hrs a day; if I am working then I run AC for 6+hrs. Generator provides plenty of power for AC and all other things to run and will max out 55A charging to the batteries. However generator is not enough to fully recharge; especially when on colder days or high elevation I may not even need to run AC, running generator would be a waste.
3. Initially I was not thinking to go with solar; however now that I know generator alone will not be enough unless I run it all day long; I need to maximize my solar system and to use it combined with generator charging. RV is pre-wired with 10AWG wire; it runs through entire length of an RV - roof hookups for panels are on back of RV - solar charger controller hookup is at front of RV - 10AWG wire x ~30' length. The roof is another issue, there is only enough room for maximum 3 200W (60" x 27") or 2 400W (80"x 40") panels. Per https://www.renogy.com/calculators#tab_solar-cable 10AWG should be enough up to 30A. 800W of solar power paired with e.g. Victron 150 | 60 should provide about 3-3.5KWh of charge which is about 50% of battery capacity. Any recommendations for 400W solar panels?

 

[time2roll]

@time2roll

is this the model number: GP-ISW2000-12 that you recommend? This is more than double the price vs e.g. GIANDEL 2200W inverter; what makes it worth double the price?

Worth double? Nothing that I know of. Many seem to like the GIANDEL. My Xantrex 1800 failed way too soon and so I will not go that direction again.

Panels are mostly just a commodity especially for RV use. Look for some surplus panels being sold by a local installer. Shipping can be expensive for these oversize items.

 

[Redbud]

I have been working through this problem of having a LiFePo4 with a WF-8955PEC. My battery is only 120ah, one battery.
It seemed to charge fine but I'm still doing testing. The problem I saw is that when the converter drops to 'float' mode the converter is no longer providing the current to the loads, my battery is supplying all the current. It continues until the batv drops to just below 13.2. For that last few days (lightly loaded) my battery is now at 70%, I suspect it would drop to 50%. This is not what I want.

I have seen others suggest putting a large dc load on the converter to force it to 'absorption', I found that all I needed to do is cycle the power to the converter and it begins to charge my battery, probably will only go to 13.6 but that is better then having it sit at 13.2.

I do not plan to replace the WF-8955PEC. I am sure I can find a solution. Even if it is to periodically cycle the power to the converter or disconnect the battery during certain times.

Randy

 

[HRTKD]

I found that all I needed to do is cycle the power to the converter and it begins to charge my battery, probably will only go to 13.6 but that is better then having it sit at 13.2.

I saw the same thing with my IOTA Engineering converter that had a LiFePO4 charge profile. I wasn't too concerned about it since 99% of my charging comes from solar. I solved the problem for good when I installed a Multiplus 12/3000 and removed the IOTA Engineering converter.

 

[time2roll]

I have been working through this problem of having a LiFePo4 with a WF-8955PEC. My battery is only 120ah, one battery.
It seemed to charge fine but I'm still doing testing. The problem I saw is that when the converter drops to 'float' mode the converter is no longer providing the current to the loads, my battery is supplying all the current. It continues until the batv drops to just below 13.2. For that last few days (lightly loaded) my battery is now at 70%, I suspect it would drop to 50%. This is not what I want.

I have seen others suggest putting a large dc load on the converter to force it to 'absorption', I found that all I needed to do is cycle the power to the converter and it begins to charge my battery, probably will only go to 13.6 but that is better then having it sit at 13.2.

I do not plan to replace the WF-8955PEC. I am sure I can find a solution. Even if it is to periodically cycle the power to the converter or disconnect the battery during certain times.

Randy

As long at the RV is plugged in the lithium battery is much happier at 50% vs 100%. I don't see the issue.

Now if fast charging on a generator and looking for Boost Mode at 14.4 volts that could be an issue. Battery may need to get well below 13.2v to trigger boost. Otherwise going to 13.6 every time the RV is moved or resting long term at 13.2 is fine.

 

[time2roll]

I saw the same thing with my IOTA Engineering converter that had a LiFePO4 charge profile. I wasn't too concerned about it since 99% of my charging comes from solar. I solved the problem for good when I installed a Multiplus 12/3000 and removed the IOTA Engineering converter.

Does the IOTA lithium profile re-bulk once a week like the standard profile?

 

[HRTKD]

Does the IOTA lithium profile re-bulk once a week like the standard profile?

Yes, it does. You can find more details about the IQ4 LiFePO4 charge profile here:

https://www.donrowe.com/v/vspfiles/pdf/iq-lifepo_owners_guide.pdf

 

[RoadTurtle]

Short story, WFCO chargers are junk. They are well known for having bad or inop charging profiles, never going into bulk, and and just sending a constant voltage to the battery. On trailer forums, you'll hear people complaining their FLA batteries dying in 2 years. I can just about guarantee the owners either are hooked up to shore 24/7 or they regularly deplete the batteries.
.
In my TT, I changed it out the 8955 for a specialty progressive dynamics unit made for Best Converter (reseller). This was for my lead acid batteries, and it worked fine, but I never measured loads.
.
Moving on the 5th wheel, I changed out the FLA PD for LFP PD charger. My charging rate was much lower than I expected, 25a vs rated 60a. Here's where it got really interesting, AFTER fixing two very bad connectors, I still have a 1.5v voltage drop between the charger and the battery bank, which would account for much of the lower amp charging rate. The charger is currently disconnected and just sitting there collecting dust, as I let the MP II managing battery charging as needed. PD is more of a spare, just in case I ever need it.

 

[Redbud]

As long at the RV is plugged in the lithium battery is much happier at 50% vs 100%. I don't see the issue.

Now if fast charging on a generator and looking for Boost Mode at 14.4 volts that could be an issue. Battery may need to get well below 13.2v to trigger boost. Otherwise going to 13.6 every time the RV is moved or resting long term at 13.2 is fine.

For me the issue is that I want those batteries to be full for the situation when I need to switch over to battery power.

 

[sunshine_eggo]

Short story, WFCO chargers are junk. They are well known for having bad or inop charging profiles, never going into bulk, and and just sending a constant voltage to the battery. On trailer forums, you'll hear people complaining their FLA batteries dying in 2 years. I can just about guarantee the owners either are hooked up to shore 24/7 or they regularly deplete the batteries.
.
In my TT, I changed it out the 8955 for a specialty progressive dynamics unit made for Best Converter (reseller). This was for my lead acid batteries, and it worked fine, but I never measured loads.
.
Moving on the 5th wheel, I changed out the FLA PD for LFP PD charger. My charging rate was much lower than I expected, 25a vs rated 60a. Here's where it got really interesting, AFTER fixing two very bad connectors, I still have a 1.5v voltage drop between the charger and the battery bank, which would account for much of the lower amp charging rate. The charger is currently disconnected and just sitting there collecting dust, as I let the MP II managing battery charging as needed. PD is more of a spare, just in case I ever need it.

IMHO, everything you describe above is attributable to the garbage wiring between the converter and the batteries. that's the real issue with converters. I have a PM4-100 I use with a 1000Ah 12V bank located only 3 feet from the battery. it works flawlessly. the same one installed in a motorhome with 20+ of marginal wire between the converter and the battery performs like crap.

 

[time2roll]

For me the issue is that I want those batteries to be full for the situation when I need to switch over to battery power.

To my knowledge there is no converter that will properly float an LFP at 90-95% automatically. Possibly the Powermax boondocker using fixed adjustable voltage mode.

https://powermaxconverters.com/product/pm3-mba/

Consider a separate battery charger to top up the battery and disconnect when using utility power. Of course manual intervention would be needed if utility power was lost unexpectedly.

Otherwise need something programmable. I use solar and a programmable controller.

 

[Redbud]

Short story, WFCO chargers are junk. They are well known for having bad or inop charging profiles, never going into bulk, and and just sending a constant voltage to the battery. On trailer forums, you'll hear people complaining their FLA batteries dying in 2 years. I can just about guarantee the owners either are hooked up to shore 24/7 or they regularly deplete the batteries.
.
In my TT, I changed it out the 8955 for a specialty progressive dynamics unit made for Best Converter (reseller). This was for my lead acid batteries, and it worked fine, but I never measured loads.
.
Moving on the 5th wheel, I changed out the FLA PD for LFP PD charger. My charging rate was much lower than I expected, 25a vs rated 60a. Here's where it got really interesting, AFTER fixing two very bad connectors, I still have a 1.5v voltage drop between the charger and the battery bank, which would account for much of the lower amp charging rate. The charger is currently disconnected and just sitting there collecting dust, as I let the MP II managing battery charging as needed. PD is more of a spare, just in case I ever need it.

Perhaps WFCO chargers aren't great, although I believe almost nothing on other forums, that isn't backed up with fact. Not that they are wrong, maybe they're right.
I don't know why WFCO can't just make a simple switch to change the charger for an Li bat. I sent then an email asking about the logic for each stage. They responded quickly but didn't answer many of my questions. The suggestion was to spend $200 on a different model, with 'auto detect'. And a link to theory-of-operation was provided.
I cycled power to my 8955PEC, it then went into absorption of 13.7vdc (measured, they quote 13.6) which is fine for my Li. Then it stayed in absorption for 3days. Again fine for the LiFePo, I suspect not so great for lead acid. Their specs stated the longest it would stay is 44hrs, I'm not sure if that is always 44 or 44 max? I wonder if I would cycle power if it would go back into absorption, or if a minor battery run would trigger absorption for 44hrs again.
Bulk mode is intended for "a significantly discharged battery". When I worked in the industry we also would not go to bulk very often with our charging system. Going to bulk mode too often will shorten the life of a lead acid battery.

 

[time2roll]

Perhaps WFCO chargers aren't great, although I believe almost nothing on other forums, that isn't backed up with fact. Not that they are wrong, maybe they're right.
I don't know why WFCO can't just make a simple switch to change the charger for an Li bat. I sent then an email asking about the logic for each stage. They responded quickly but didn't answer many of my questions. The suggestion was to spend $200 on a different model, with 'auto detect'. And a link to theory-of-operation was provided.
I cycled power to my 8955PEC, it then went into absorption of 13.7vdc (measured, they quote 13.6) which is fine for my Li. Then it stayed in absorption for 3days. Again fine for the LiFePo, I suspect not so great for lead acid. Their specs stated the longest it would stay is 44hrs, I'm not sure if that is always 44 or 44 max? I wonder if I would cycle power if it would go back into absorption, or if a minor battery run would trigger absorption for 44hrs again.
Bulk mode is intended for "a significantly discharged battery". When I worked in the industry we also would not go to bulk very often with our charging system. Going to bulk mode too often will shorten the life of a lead acid battery.

From the operation link:

Testing has shown that a completely discharged battery of 11.9 V dc connected to a WFCO converter in absorption mode with an output of 13.6 V dc and having a 20 amp lighting load connected to the converter will charge the battery to its fully charged level of 12.7 V dc in fewer than three hours.

This statement is just false. No possibility of lead acid going from dead to 100% in three hours using 13.6 volts.

I have found the WFCO will go to boost mode easily in the right conditions. Just need to load the converter to well below 13.2 volts. The trick is it has to be forcing the converter output voltage to sag at the output terminals not the battery. Would seem easy with a lead-acid down at 11.9 volts but with 60 amps feeding a barely adequate connection the voltage at the converter pops right up to 13.4-13.6 and the WFCO thinks all is normal. No switch to boost 14.4 volts.