Will WFCO Auto Detect charge RV’s lithium batteries? —Part 2

Dear Dave,
I can’t find the model number of the WFCO converter anywhere. —Paul, 2022 Rockwood Mini Lite 2109S

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This is a follow-up on the charging profile for lithium batteries and the WFCO converter that is in Paul’s rig. [Will WFCO Auto Detect charge RV’s lithium batteries?] I talked with him on the phone and he sent the following photos.

This is not your traditional distribution center, like we assumed from the first photo sent earlier, rather just a converter without much of a housing.

In my earlier post we got some good information from Dennis at Progressive Dynamics and the technician from Expion 360. Since then I had a good conversation with a rep from Battle Born and WFCO.

Here is the information from Battle Born Batteries

Hey, Dave,
Thanks for reaching out.

Page 7 of the attached manual should provide you with some clarity. The Lithium mode with the 8700AD or 8900AD converter will provide a two-stage charging profile titled, Charge Mode and Power Mode. Charge Mode will boost the voltage up to 14.6v for up to 4 hours. Once a battery reaches cell balancing between 14.2v-14.6v or 4 hours has passed, the converter will then switch over to Power Mode to help supply power to DC circuits in the RV.

Preference on charge profile is a bit subject: With this converter, we require the two-stage lithium smart charging profile to be compatible.

In terms of generalities: We recommend a bulk and absorption between 14.2v and 14.4v, with a float voltage between 13.2–13.6v. Now, there are hundreds of thousands of chargers on the market with minor differences in what we recommend. There could be a charger on the market that will bulk and absorb at 14.3v but has a float of 13.9v; we see no issues using a charger like this. Float voltage can vary somewhat but bulk and absorption are pretty standard between 14.2v and 14.6v.

The time in which a battery charger outputs 14.2–14.6v is up to the charger manufacturer. WFCO does a max of 4 hours and states that if you do not hit 14.2–14.6v in those 4 hours, unplug, let things cycle for a few minutes, then plug back in and let the converter go back to charging the batteries. You are correct that once the battery gets discharged somewhat below the float value, it will automatically begin recharging. I cannot recall that voltage offhand or find it in the manual.

Here is the cover of the manual with a picture that looks very much like Paul’s converter.

Information from WFCO

Then I got a call from a technician at WFCO. He confirmed it is a two-stage converter and identified the model. He indicated that WFCO had designed their converters for the Battle Born/Dragonfly charge profile as they were the largest supplier of lithium in the market. As indicated earlier, there are thousands of different batteries and converters. Here is what I got:

Per our discussion, please see the below charging information.

Lead Acid Charging Profile—

• 32 amps to enter bulk charge on v1.17
• 23 amps to enter bulk charge on v1.19 and v1.21A

Will charge up to 4 hours in bulk charge unless the battery begins to pull below 8 amps, then the voltage will drop back down to 13.6V.

Lithium Charging Profile—

• 32 amps to enter bulk charge on v1.17
• 23 amps to enter bulk charge on v1.19 and v1.21A

Will charge up to 10 hours in bulk charge mode unless the battery begins to pull below 8 amps, then the voltage will drop back down to 13.6V.

More info from WFCO

Then the tech from WFCO sent this to me Monday morning:

Good morning, Dave,
The model of the converter is going to be on the reader’s door assembly. In this case, the unit that the reader has is going to be a WF-8955-AD. The converter itself specifically is a WF-8955-AD-MBA (man board assembly).

The bulk stage charge rate will depend on which mode that the unit is in. In lead acid mode, the bulk rate will jump up from 13.6V to 14.4V. in lithium mode the bulk charge rate is the same voltage for charging at the 14.6V. This also changes the bulk rate charge times.

In lead acid mode it will charge at the bulk rate for 4 hours before it would stop the bulk charge. In lithium mode it will charge at the 14.6V bulk charge rate for up to 10 hours before it times itself out. For larger battery banks the customer may need to “cycle” or reset the converter, if they hit this timer, to continue charging.

So my question is how will the Lithium Battery manufacturers warrant their batteries for 10 years or longer if the charging profiles are so “all over the board”? It will be interesting to see.

 You might also enjoy this from Dave 

Ask Dave: Is lithium ion or lithium iron phosphate battery better in RV?

Dear Dave,
What’s the difference between a lithium ion battery and a lithium iron battery? Is one safer than the other for a 33′ 5th wheel? —Troy, 2005 Alfa See Ya

Read Dave’s answer.

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

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