Is my WFCO converter compatible with lithium batteries?

Answered by RV Parts Giant · Upland, CA · September 25, 2026

Short answer: Only if it has a selectable lithium charge profile. A converter on a lead-acid profile spends most of its life floating around 13.6 V and never fills a LiFePO4 bank, and any unit with an equalise or desulfation mode can damage lithium and must be disabled or replaced. Check the label and manual of your specific WFCO model; if there is no lithium setting, fit a charger you can configure, such as the Blue Smart IP22 or Smart IP43.

The battery is the easy part of a lithium swap: it fits the tray and lands on the same terminals. The converter is where "drop-in" stops being true, because a converter built around a lead-acid charge profile is wrong for lithium in two different directions.

The two ways a lead-acid converter fails lithium

It undercharges. Most factory converters spend the bulk of their time in a float stage around 13.6 V. A lead-acid battery is happy there. A LiFePO4 battery held at that voltage settles well short of full, which is why owners who swap the battery and change nothing else report an expensive new bank behaving like a smaller one.

Some actively harm. Converters with an equalisation or desulfation mode periodically push a deliberately high voltage to stir the electrolyte in a flooded battery. Lithium has no electrolyte to stir and does not tolerate it. If your converter has an equalise mode, it must be disabled or the converter replaced.

How to check your WFCO unit

WFCO has sold many converter decks over the years and they are not all the same, so do not rely on what someone else's model does. Three places to look:

The label on the deck. Newer converters from several makers state a lithium or LiFePO4 mode on the label or have a switch for it. If the label lists only flooded, AGM and gel, it is a lead-acid profile.
The manual for your exact model number. Look for the float voltage and for any mention of an equalise or desulfation stage.
A meter at the battery on shore power. Once the battery is charged, read the voltage the converter holds it at. A steady 13.6 V or thereabouts on a bank that never reaches full is the lead-acid float stage at work.

If you find a genuine lithium mode, set it and confirm the absorption and float voltages against your battery's datasheet. The correct numbers come from the battery manufacturer, not from a generic preset.

If it has no lithium setting

You have two options, and both keep the existing 12 V distribution in place.

Replace the converter deck with one that has a real lithium profile.
Add a configurable charger and leave the old converter to run the 12 V loads. The Blue Smart IP22 and the higher-output Smart IP43 both let you set the profile from your phone and both plug into a standard US outlet. Set the voltages to your battery's figures.

What else changes with lithium

The converter is only the first item. A lithium bank will also take everything the alternator can give it for as long as it can give it, so the tow vehicle or motorhome charging path needs a DC-DC charger such as the Orion XS, sized to the alternator rather than the battery. Any solar controller needs its profile changed too. And because lithium's voltage tells you almost nothing about how full it is, a SmartShunt stops being optional.

Tell us your battery model and what charges it today and we will work through the list before you order anything. Everything ships from Upland, California.