Xantrex Freedom SW2012 12V 2000W Inverter/Charger

The Xantrex Freedom SW2012 12V 2000W Inverter/Charger (model 815-2012) is the second-generation Freedom SW in the 2000-watt class, completely redesigned to bring the features of the higher-output Freedom SW models into the 2000W price point. Pure sine wave 2000-watt continuous AC output (4000-watt peak surge for 5 seconds), integrated 100-amp 12V DC battery charger with power-factor-corrected multi-stage charging, built-in transfer switch with sub-10-millisecond transfer time, parallel and series stacking capability for more advanced configurations, and the new Generator Support Mode that enables the inverter to supplement a generator when AC loads exceed generator capacity. UL458 with marine supplement, CSA, ABYC, and FCC Class B approvals.

What an inverter / charger does. Three functions in one box. As an inverter, it takes 12V DC battery power and converts it to 120V AC household power so you can run AC appliances, tools, electronics, and HVAC equipment from your battery bank when shore power isn't available. As a charger, it takes 120V AC shore power and converts it to charging current to recharge the same battery bank. The integrated transfer switch automatically routes the AC load to whichever source is available (shore power if present, inverter battery power if not). One unit, three functions, fewer parts to fail.

Pure sine wave AC output is the right output waveform for sensitive electronics, motor loads, and HVAC equipment. Cheaper modified-sine-wave inverters work for resistive loads but cause problems with motors (overheating, premature failure), modern HVAC compressors (sensor faults, compressor damage), microwaves (long cook times, audible buzz), and sensitive electronics. Pure sine wave produces clean AC indistinguishable from utility power, which means everything just works the way it would on shore power. The Freedom SW line is built around pure sine wave output as the headline feature.

Sub-10-millisecond AC transfer time is the major upgrade in this generation. Previous-generation inverter / chargers transferred between shore and battery power in about 30 to 50 milliseconds, which is fast enough that some loads survive the transition but slow enough that some loads (sensitive electronics, certain motor controls, some HVAC compressors) drop out and have to restart. The SW2012 transfers in under 10 milliseconds, which is fast enough that even sensitive loads don't notice the transition. Especially important for liveaboard installs where shore-to-battery transfers happen routinely as people move on and off the boat.

Generator Support Mode is the feature that distinguishes this generation from the older SW models. With Generator Support enabled, the inverter monitors the AC load and the generator output. When the load exceeds what the generator can deliver, the inverter automatically supplements the generator with battery-sourced AC power. This lets you run high-load appliances (air conditioning, microwave, electric water heater) on a smaller generator than you'd otherwise need, because the inverter handles the surge and the generator handles the steady-state load. For RV and marine installs where generator size is constrained by space and weight, Generator Support is a serious capability upgrade.

The integrated 100-amp 12V battery charger handles shore-power and generator-power charging. Power-factor-corrected multi-stage charging uses less shorepower per amp of charging current than older non-PFC chargers, which means more usable shore power for AC loads while charging is happening. Bulk / absorption / float / equalize charge stages with chemistry-specific profiles for lead-acid, AGM, gel, and lithium batteries. Temperature-compensated charging adjusts charge voltage based on ambient temperature for accurate charge in any climate.

Parallel stacking lets you connect two SW2012 units in parallel for 4000 watts of continuous AC output (double the single-unit output). Series stacking lets you connect two SW2012 units in series for 120/240V split-phase output (useful for boats and RVs that need 240V appliances like clothes dryers or large air conditioners). Stacking requires the appropriate stacking cable (Xantrex part 808-9005, sold separately). For most installs, a single SW2012 is sufficient, but the stacking capability provides a clear upgrade path for owners who add loads over time.

The 4000-watt 5-second surge rating is the feature that determines whether the inverter can actually start motor loads. Compressor loads (RV air conditioners, residential refrigerators, freezers, deep wells) draw 5 to 7 times their continuous current at startup, but only briefly. The 4000W surge handles essentially every common compressor load you'd expect to run on a 2000W inverter (typical 13.5K BTU RV roof-top A/C with appropriate soft-start, residential apartment-size refrigerator, microwave, and similar).

UL458 with marine supplement is the safety certification that matters for marine installs. UL458 is the U.S. standard for marine inverters and inverter / chargers, with the marine supplement adding the additional requirements for installation aboard recreational and commercial vessels. ABYC compliance means the unit meets the American Boat and Yacht Council standards for marine electrical installations. CSA covers Canadian use. FCC Class B covers the radio-frequency emission standards required for marine electronics that don't interfere with VHF communications.

Approved for a wide range of mobile applications: commercial vehicles, emergency vehicles, recreational vehicles (RVs), marine vessels, construction equipment, and military applications. The same SW2012 chassis serves all these markets because the core requirements (clean AC output, reliable charging, fast transfer, marine-grade construction) are similar across all mobile power applications.

Battery overvoltage and undervoltage protection prevents damage from out-of-range battery conditions. Over-temperature shutdown protects against overheating events. Automatic overload protection prevents damage from sustained overcurrent draw. Short-circuit protection trips the unit safely if a downstream short occurs. Integrated, resettable AC breakers protect the AC output circuits without requiring external breaker boxes for typical installations. Reverse battery protection prevents damage if the DC connections are reversed during install.

Two AC outlets on the unit handle direct-connection of small loads. For most installs, the AC output wires to a downstream AC distribution panel that handles all the boat or RV AC circuits. The integrated outlets are convenient for testing and for quick connection of single loads.

Mounting and dimensions. Unit dimensions are 7.75 inches high by 13.5 inches wide by 15.25 inches long. Mount with the cooling fins running vertically and at least 3 inches of clearance around the case for proper airflow. Battery cables sized for the 12V continuous load (typically 4/0 AWG for the main DC connections at 2000W with appropriate fusing close to the battery). Optional remote control panels (sold separately) extend the operator interface to a more convenient location.

What this isn't. It is not a 24V or 48V inverter (this is the 12V variant). It is not the 3000W variant in the same Freedom SW line (the 815-3012 has 50 percent more output and a 150A charger but in the same chassis style). It is not the smaller Freedom XC line (which is more cost-effective for installs that don't need the SW's advanced features like sub-10ms transfer and Generator Support).

2-Year Limited Xantrex warranty. Same-day shipping before 3 PM ET on in-stock units.