An RV converter changes shore or generator AC (alternating current) into DC (direct current) for house equipment and battery charging. An inverter changes battery DC into AC for connected appliances. An inverter/charger combines both functions; identify what is installed and which circuits it supplies before choosing equipment.
This guide uses a common US RV arrangement: 120V AC and a 12V house battery system. Other battery voltages exist; match the equipment to your actual system.
Converter, inverter and inverter/charger at a glance
| Device | Power direction | What it provides |
|---|---|---|
| Converter/charger | AC → DC | DC house power and battery charging while supplied with AC. It does not produce AC from the battery. |
| Plain inverter | DC → AC | Battery-powered AC for connected loads. It does not charge the battery from shore power. |
| Inverter/charger | AC → DC for charging; DC → AC for inverter operation | Both functions, plus transfer of incoming AC to connected circuits. Circuit coverage depends on the installation. |
The Progressive Dynamics converter FAQ describes the two DC jobs: powering house equipment and charging the battery when AC is available. Xantrex’s inverter/charger overview adds a built-in switch that chooses between incoming AC and inverter power for connected circuits.
Follow the power, not just the name
On hookups, incoming AC can supply your wall outlets while a separate branch feeds the converter. Your microwave’s power does not have to travel through the battery first. Without hookups or a generator, the battery can still run DC equipment; an inverter supplies only the AC loads connected to it.
Shore or generator AC available
Two branches from the same AC source:
House battery only
Two possible paths from the same battery:
Conceptual separate-unit layout; an inverter/charger combines the conversion jobs. Protection and source switching are omitted. This is not a wiring diagram.
That is why lights and the water pump can work while household-style outlets are dead. It may be the RV’s normal arrangement. A furnace blower also uses the DC side; our furnace battery-runtime guide helps plan that load without adding an inverter.
Find out what your RV already has
Use labels, the owner’s manual and normal user controls. A remote labeled “inverter” may control a unit that also charges batteries; identify the main unit before deciding what you have.
nuCamp’s explanation shows how a power center can contain a converter alongside AC breakers and DC fuses. The converter changes power; the breaker/fuse panel distributes and protects circuits. Replacing the charging function does not automatically mean replacing the whole power center.
- Record the full model number. Use an accessible label or the RV’s equipment list. WFCO’s model-number guidance gives different label locations for different series. Do not remove electrical covers to hunt for it.
- Read the function beside each rating. These illustrative specification lines show what to look for in the exact manual, not settings to enter:
- 120V AC input; 45A DC charging output: identifies a charging function. A converter/charger supplies DC and charging without an inverter function.
- Inverter output: 120V AC, 1,000W: identifies AC power from the battery. This rating alone does not establish a charging function.
- Both charging and inverter outputs for the same unit: identifies an inverter/charger. Check both specifications; an AC pass-through rating alone does not prove either function.
- Identify the connected outlets. Check circuit labels and the RV’s documentation. If the manual provides an owner check, use its normal controls and a small known-working appliance to confirm the intended outlet; do not open panels or move wires.
- Record the source and mode. Note shore/generator connected, inverter enabled or disabled, charger mode and any fault message. An outlet working on shore power does not demonstrate that it works from the battery.
An inverter may serve only part of the RV
Victron’s MultiPlus-II 120V manual gives a concrete example: its second output, AC-out-2, disconnects during battery operation. Check which outlets your installation supplies before treating a dead outlet as a failed inverter.
If an outlet that previously worked under the same conditions stops working, follow our RV outlet troubleshooting guide. Keep checks to the accessible controls and the procedures your manual permits; wiring faults need a qualified technician.
Which function solves your problem?
| Your situation | Function to investigate | Next step |
|---|---|---|
| You only need DC equipment while unplugged | The battery/DC system may already do the job. | Check whether you can keep your converter. |
| You want an AC appliance to work from the battery | Inverter output to that appliance or circuit. | Consider a separate inverter. |
| You need battery-powered AC and a new shore charger | Combined inverter and charger functions. | Consider an inverter/charger. |
| You are plugged in but the battery keeps falling | The charging path, settings or available output. | Use the plugged-in charging checks first. |
| Charging works but takes longer than expected | Charging current left after RV loads, and how much the battery can accept. | Use the battery charge-time planner. |
These choices identify the job to investigate. Whether equipment is suitable still depends on its ratings, battery compatibility and the circuits connected to it.
Keep the converter when charging and DC use are covered
If you use AC appliances on hookups and only DC equipment while unplugged, a working, compatible converter/charger may already cover your needs. An inverter is an option when you want battery-powered AC appliances; it is not required simply because you camp without hookups.
A lithium battery change also does not automatically require an inverter/charger. Check the existing charger’s supported battery types and settings against the battery maker’s requirements. WFCO’s Auto-Detect FAQ, for example, supports lithium iron phosphate (LiFePO4) on those models; that does not make every WFCO converter lithium-compatible.
Add a plain inverter when AC from batteries is the missing job
A suitable separate inverter can work alongside a compatible converter. Give the installer three clear requirements:
- Appliance connection: direct use of the inverter’s outlets or integration with selected RV circuits.
- Outlet coverage: which outlets need battery power. Buying a larger inverter alone does not connect it to more outlets.
- Avoid a charging loop: when running from the battery, prevent the inverter from powering the existing converter. Otherwise the battery powers an inverter that powers a charger trying to recharge that same battery, wasting energy.
Consider an inverter/charger when both jobs need attention
A combined unit can make sense when you need battery-powered AC and a new shore charger, or want automatic switching between supplies. It can take over a separate converter’s charging role when correctly specified and installed; the installer must decide what happens to the old converter and its connections.
When suitable shore or generator power is available, pass-through sends it through the unit to connected AC circuits. Charging shares that limited supply with other equipment. Some models can also use battery power to supplement a limited hookup, as the MultiPlus-II’s PowerControl and PowerAssist descriptions explain.
A working outlet does not prove the battery is charging
An inverter/charger can pass AC through while charging is switched off, reduced or blocked by a fault elsewhere. Likewise, a converter can power DC lights without proving charge is reaching the battery. Read the charger status and battery information before replacing either device.
Use our 30-amp load planner to account for charging alongside appliances on a limited hookup.
Check three different ratings before buying
The numbers on these products describe different jobs. A charger’s DC amp rating is not the same as the RV’s shore-power amp rating, and an inverter’s watt rating does not tell you how long the battery will last.
- Converter/charger output: DC amps and charging settings suitable for your battery type. Other DC equipment shares that output; the battery may accept less than the charger can supply.
- Inverter output: continuous AC watts, startup capability and its duration, output waveform and operating-temperature limits. Use appliance electrical-input ratings, not a microwave’s cooking-output figure.
- Transfer/pass-through rating: the AC current the unit can pass to its connected circuits. It does not mean every RV circuit is supplied or guarantee support for both incoming power lines in a 50A RV.
The Freedom XC 1000/2000 manual provides a real example: separate tables for “AC output for inverting” and “DC output for charging.” Those two functions identify a combined unit; its transfer rating is a third, separate limit.
The battery side carries much more current
For an illustrative 1,000W AC load, assume 12V at the inverter input and 90% efficiency:
1,000 ÷ (12 × 0.90) ≈ 93A DC
Actual input voltage and efficiency vary; lower voltage or efficiency increases the current needed for the same AC output.
That is before other DC loads and startup peaks. Check the battery’s allowed discharge current, its battery-management system where fitted, and the installed DC connections—not just its amp-hour capacity. This example does not size cables or fuses.
Stored energy determines endurance; current limits determine whether the bank can support the load at all. Our battery-monitor guide explains monitoring options, but a display does not increase either limit.
Take these details to the next decision
- Installed equipment: full model numbers, battery voltage/type and current charging settings.
- Wanted AC loads: electrical-input watts, startup needs, expected hours of use and which must run together.
- Outlet coverage: which circuits already work on battery and which you want added.
- The actual gap: charging, battery-powered AC, transfer between supplies—or no upgrade needed.
Once the job is clear, our RV converter guide and RV inverter guide provide equipment comparisons. Confirm current specifications and battery compatibility before choosing a replacement.
For hardwired changes, have a qualified installer plan separation of power sources, electrical protection and which circuits will receive power. Xantrex’s installation instructions warn against connecting an external AC source to inverter output wiring. Never feed a wall outlet backward to energize the RV.
