Which Victron charger should replace my WFCO converter for a lithium bank?

Start with why the converter has to go, because it decides which replacement you need.

A factory converter is built around a lead-acid charge profile, and that profile is wrong for lithium in two directions. It undercharges: many converters spend most of their life in a float stage around 13.6 V, which is fine for lead-acid, but a lithium bank sitting there settles well short of full. That is why owners who swap the battery and change nothing else report an expensive new bank behaving like a smaller one. And some actively harm: a converter with an equalise or desulfation mode periodically pushes 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 unit has an equalise mode, it must be disabled or the unit replaced.

Charger only, or charger plus inverter?

If you are happy with the rest of the system, replace the converter with a configurable charger. The Blue Smart IP22 and the Smart IP43 both set their profile from your phone and both come in several current ratings, which is the number that matters.

If you also want 120V off the battery, a MultiPlus replaces the converter and the inverter in one box and adds a transfer switch, so shore power passes through and the unit charges; unplug and it inverts. For most campers that is the tidier installation, and it is why we usually point people there rather than at a separate charger and inverter.

Sizing it

Charge current is the specification to get right, not wattage. As a rule of thumb, lithium is comfortable at 0.3 to 0.5C, so a 200 Ah bank suits roughly 60 to 100 A of charging. Undersizing only means slower charging on shore power; oversizing against a small shore supply means the breaker trips, though Victron's PowerAssist handles that by limiting input current.

Check what the converter was actually feeding, too. If it also powers the 12V distribution panel directly, the replacement has to keep that fed, or the panel has to be moved onto the battery side with appropriate fusing.

Set it from the datasheet, and check every other source

Absorption and float voltages come from your battery manufacturer, not from a generic lithium preset — different LiFePO4 packs specify different numbers. And a system where the new charger is set to lithium while the solar controller is still on a lead-acid profile behaves unpredictably, because whichever source is active at the time decides the outcome. Set every charging source, including the alternator path.

Finally, fit a shunt-based monitor. Once the converter is gone you have no reliable idea of state of charge from voltage alone on a lithium bank, because the voltage stays nearly flat until it is nearly empty. Tell us your bank size and shore supply and we will confirm the model before you order. Everything ships from Upland, California.