Replacement for WF-9855 In 5th Wheel Switching To Lithium Batteries

Updated 07/27/2026 | Published 04/21/2026

Products Featured in This Question

WFCO Auto-Detect RV Converter Charger - Deck Mount - 12V - 55 Amp

(61)

$248.99

Progressive Dynamics 9300 Series RV Converter Charger - 12V - 60A

(324)

$298.57

Question:

I am replacing a WFCO 55 AMP Power Converter in my fifth wheel camper. Model Number WF-9855. I am installing Lithium Batteries. What converter will work for my application? Both WFCO and Power Dynamics brand. Thank you

asked by: TJ S

Expert Reply:

Hey TJ! The most direct replacement is the WFCO Auto-Detect RV Converter Charger # WF38FR. This is the WF-9855-AD, so the same model you have now but with the auto-detect technology.

The converter will identify the battery type (so in this case lithium) and use the correct charging profile automatically. I’ve actually switched to one of the auto-detect models in my own trailer and it’s a really simple, hands-off setup.

If you’re wanting to go with Progressive Dynamics, the closest option is the 60A unit # PD79RR. They don’t make a 55A version anymore, so this would be a slight bump in output, but that’s generally not an issue. It also includes the Charge Wizard pendant so you can manually control the charging mode if needed.

Both WFCO and Progressive Dynamics are solid choices, it really comes down to whether you want the automatic lithium detection or the manual control option.

What kind of 5th wheel are you working on?

expert reply by: Robin H

WF-9855-AD-CB
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Michael H.

7/26/2026

I just purchased lithium battery and thinking about switching to the progressive from the Wfco. My current one has auto switch but have heard not reliable. So thinking about changing as a precaution. Your thoughts.

Robin H.

7/27/2026

@MichaelH I think sticking with Progressive Dynamics is the safe choice here. I have a WFCO auto-detect and it has never had a problem. However, plenty of people have run into issues where it doesn't work properly with their lithium setup. Both are solid options, but I've never heard of that issue with the PD converters so you're just avoiding the issue altogether.