Best RV Converter/Chargers, Including Lithium-Compatible Models

Unlike an inverter, which turns battery DC into usable AC, a converter/charger runs the opposite direction: it takes 120V AC from shore power or a generator and steps it down to 12V DC, both to charge the battery bank and to directly run the RV's 12V circuits while plugged in. It typically sits inside a power center alongside the breaker panel and is the part most people never think about until a battery swap exposes it.

Lithium charge profiles publish an absorption voltage around 14.6V, the figure LiTime lists for its own dedicated lithium chargers, which is meaningfully higher than the fixed setpoint a lead-acid-profile converter typically provides. A lead-acid converter will charge a lithium bank, but it stalls out well short of full and never gets there, which quietly shortens the usable capacity of every trip. This is the single most common mistake in a do-it-yourself lithium conversion: buying the battery and skipping the converter.

Not every converter swap is necessary. Some newer converters already ship with a selectable or automatic lithium mode, like the WFCO unit's auto-detect switching, so it is worth checking the existing unit's own manual and any dip switches or selector settings before buying a replacement. A converter with a manufacturer-documented lithium charge profile can often stay in place, while one whose documentation only describes a fixed lead-acid setpoint, with no lithium mode mentioned anywhere in the manual, needs to go regardless of how new or expensive it was.

All four units here are rated at 55A, so the charge profile documentation and the mount style are what actually separate them.

All four converters in this roundup are deck mount units, meaning they are designed to be swapped into an existing power center slot rather than mounted freestanding. That matters because most trailers, particularly those built around a WFCO power center, have a specific footprint and connector layout the original converter fills. A genuine WFCO replacement like the WF-9855-AD-CB is built to drop into that exact slot, while a different brand's deck mount unit may need the wiring harness adapted even though it is technically also a deck mount design. Confirm the existing power center's model and connector style before ordering, rather than assuming any 55A deck mount unit is a guaranteed fit.

A converter only moves power in one direction, from AC shore power down to 12V DC. It has no ability to invert the battery's stored DC power back into usable AC when unplugged, which is the entire job of a separate inverter or an inverter/charger. Choosing a standalone converter, as opposed to an inverter/charger, only makes sense when a separate inverter is already in place or planned, since the converter alone leaves the rig with no AC power at all once it is disconnected from shore power or a generator.

Most deck mount converters connect through a handful of standardized leads: AC input, 12V DC output to the distribution panel, and a battery connection, often through a common connector block shared with other components in the power center. A like-for-like swap, same amp rating and same mount style, typically means unplugging the old unit's connector block and plugging in the new one, without needing to touch the breaker panel or the 12V distribution wiring at all. A converter with a different mount style or a non-standard connector, on the other hand, can turn what looked like a simple swap into a wiring project, which is why matching the physical connector layout matters as much as matching the amp rating.

A converter's cooling fan typically cycles on and off based on internal temperature, which becomes noticeable inside a small trailer parked in a quiet campground, especially overnight while the converter is actively bulk charging a depleted bank. Deck mount units installed inside a closed power center compartment tend to run quieter than units mounted in open cabinetry, simply because the enclosure dampens the fan noise, though it also means the compartment needs adequate ventilation so the converter itself does not overheat from being enclosed.

All four converters here advertise multi-stage charging, meaning the charger moves through distinct phases, typically a bulk stage delivering maximum current, an absorption stage holding a steady voltage as current tapers, and a float stage maintaining a lower voltage once the battery is full. Multi-stage charging exists specifically to avoid the battery sitting at a high voltage indefinitely, which shortens the life of both lead-acid and lithium chemistries over repeated cycles. A single-stage charger, which simply holds one fixed voltage regardless of the battery's actual state, is largely a thing of the past in this category, but it is still worth confirming that a given unit's documentation actually describes distinct stages rather than using the term loosely.

These picks were researched from published manufacturer specification sheets covering amp rating, charge profile and staging, and mount style, then cross-checked against verified owner reviews for drop-in fit and reported charge behavior on lithium banks. None of these units were tested in person for this page.

Compare these first by whether the maker documents a real lithium charge profile, not just by amp rating, since all four sit at 55A.