WFCO WF-8955PEC conversion to LiFePO4 charger

[HRTKD]

20' one way distance to battery.
6awg wire
13.6V "absorption" voltage @ converter
40A charge current

You had 6 gauge wire? Lucky dog. None of mine was better than 8 gauge.

I have a situation in my toy hauler where the bunk bed motor (at the very back of the trailer) will not run most of the time if the converter isn't on for the 12 volt flooded lead acid battery on the tongue. Extreme ends of the trailer. Somehow the bunk bed motor circuit does not go through (terminate at) the trailer's main 12 volt distribution panel. It took me a few years of pulling fuses to realize that the bunk bed motor wasn't connected to the distribution panel. Heck, I suspect it isn't even fused at all. The converter seems to provide just enough boost to run the bunk bed motor.

 

[datdude]

I did that. I also compared to my shunt. I am using 2ga welding wire, about 8' round trip. If I don't allow solar, it charges better, but never where it should (dumping all it can until it hits ~95% SOC or 4 hours). I am not sure if you have ever used WFCO converters, but this is supported out there in the wild, in the RV forums. My trailer is at a storage facility in another town, so I can't easily just go out and drain and recharge the batteries for fun. But I have been through this exercise twice now.

 

[datdude]

Just did a quick test, unplugged my trailer and ran the batteries down to shutoff (bms protected, so not 0%). Attached is my charge graph from my shunt. Only parasitic 12v loads during charging except 1 blink mini camera on the USB port - no lights or anything during charging. This is a WF9865-AD in lithium mode. Why on earth would it be dropping the current like this if it were a constant current charger? The start is at around 60amps, then drops quickly. This is inside a building, so no solar in play. I would generally expect a charger to be putting somewhere between 55-65 amps into the battery bank here until it drops out of bulk mode, which happened at the 4hr mark before the batteries were fully charged. Thoughts anyone?

 

[sunshine_eggo]

Throttling due to internal temperature? Converters rarely have to deliver their max current for a significant amount of time.

This is why I'm extremely dubious about the converter manufacturer's "lithium solutions." It's always something.

My go to is the Powermax PM3-LK line. Regardless of how they work as chargers, you can set them to constant voltage mode.

 

[HRTKD]

Just did a quick test, unplugged my trailer and ran the batteries down to shutoff (bms protected, so not 0%). Attached is my charge graph from my shunt. Only parasitic 12v loads during charging except 1 blink mini camera on the USB port - no lights or anything during charging. This is a WF9865-AD in lithium mode. Why on earth would it be dropping the current like this if it were a constant current charger? The start is at around 60amps, then drops quickly. This is inside a building, so no solar in play. I would generally expect a charger to be putting somewhere between 55-65 amps into the battery bank here until it drops out of bulk mode, which happened at the 4hr mark before the batteries were fully charged. Thoughts anyone?

View attachment 230272

And that right there is why there is so much discontent with pretty much the entire RV type converter product line.

While I haven't graphed the charge period for my Multiplus, I've watched the numbers on the screen. That Multiplus will really put the hurt on the battery bank if I turned it loose.

 

[time2roll]

Looks like the WFCO actually pushed the battery to 14.20 volts and should be fine to call it full.
Yes. Generally the Boost mode only lasts 4 hours. How many Ah were put into what size battery?

Looks like all is working good to me. The last bit of top off is overrated and best handled by the solar.

 

[sunshine_eggo]

Looks like the WFCO actually pushed the battery to 14.20 volts and should be fine to call it full.
Yes. Generally the Boost mode only lasts 4 hours. How many Ah were put into what size battery?

Looks like all is working good to me. The last bit of top off is overrated and best handled by the solar.

Maybe you're missing some details. This is a 60A converter.



Do you actually find it acceptable that a 60A charger doesn't ever put out 60A for any meaningful time? At least 80% of the 5 hours was at 42.7A or less?

 

[time2roll]

Do you actually find it acceptable that a 60A charger doesn't ever put out 60A for any meaningful time? At least 80% of the 5 hours was at 42.7A or less?

Well yes that is low compared to an inverter/charger mounted next to the battery and I have seen far worse from WFCO.
Need more details on the connection too as in is the charge getting pushed through 25' of #6 wire? 80 amp rated may not do any better for the conditions.

Otherwise for an RV converter it looks to be working as designed. Not that the design is good. Also great to see not stuck on pushing 14.6 volts continuous like the early models.

 

[sunshine_eggo]

Well yes that is low compared to an inverter/charger mounted next to the battery and I have seen far worse from WFCO.
Need more details on the connection too as in is the charge getting pushed through 25' of #6 wire? 80 amp rated may not do any better for the conditions.

Otherwise for an RV converter it looks to be working as designed. Not that the design is good. Also great to see not stuck on pushing 14.6 volts continuous like the early models.

I did that. I also compared to my shunt. I am using 2ga welding wire, about 8' round trip. If I don't allow solar, it charges better, but never where it should (dumping all it can until it hits ~95% SOC or 4 hours). I am not sure if you have ever used WFCO converters, but this is supported out there in the wild, in the RV forums. My trailer is at a storage facility in another town, so I can't easily just go out and drain and recharge the batteries for fun. But I have been through this exercise twice now.

 

[time2roll]

Last I read the full amp rating of a WFCO was at 13.2 volts. Then the amps sag. This is typical of other converters too. I think PD rated amps is at 13.6 volts.

Only converter to really hold rated amps at full voltage that I have read is the IOTA.

 

[HRTKD]

Last I read the full amp rating of a WFCO was at 13.2 volts. Then the amps sag. This is typical of other converters too. I think PD rated amps is at 13.6 volts.

Only converter to really hold rated amps at full voltage that I have read is the IOTA.

Can't say that I was all that happy with the IOTA DLS-55 with IQ/4 LiFePO4 adapter that I had. Had to disconnect it (both AC and DC) to reset it before it would resume charging. It's probably better than most of the converters out there, but the charge I get out of my Victron components kicks the IOTA's butt.