I need a solar inverter that charges a backup battery during a grid outage.

Yes — what you want is a hybrid solar inverter / inverter-charger that can:

1. Use solar panels to power the house.
2. Charge a battery from solar.
3. Charge the battery from the grid when desired.
4. Automatically disconnect from the grid during an outage.
5. Keep selected circuits—or the whole house—running from the battery and solar.

For a U.S. 120/240V home, I’d focus on these:

Sol-Ark 15K-2P Hybrid Inverter

$5,599.99

Sol-Ark 12K-2P Hybrid Inverter

$4,269.99

EG4 12kPV Hybrid Inverter

$3,024.99

Solis S6 10kW Hybrid Inverter

$1,935.00

My top pick: Sol-Ark 15K-2P

Sol-Ark 15K-2P Hybrid Inverter

$5,599.99

The Sol-Ark 15K-2P is particularly well suited if your goal is whole-home backup. It provides 15 kW AC output, 120/240V split-phase operation, 200A grid pass-through, and 48V battery compatibility. Current listings I found are around $5,600 for the inverter before installation and battery.www.sol-ark.com+1

It also gives you considerable freedom in choosing the battery: Sol-Ark maintains a list of certified battery partners and says its systems are generally compatible with many 48V batteries.www.sol-ark.com+1

Lower-cost option: EG4 12kPV

EG4 12kPV Hybrid Inverter

$3,024.99

This is worth considering if you're trying to keep the system cost down. EG4 has a strong 48V battery ecosystem, and its hybrid inverters are designed for solar + battery + grid/off-grid operation.www.sol-ark.com+2

One important sizing question

The battery capacity and inverter size are separate decisions. For example, a 15 kW inverter with a 15 kWh battery could theoretically supply a 10 kW load for roughly 1.5 hours (less after losses and reserve).

If you tell me (a) your solar-panel size, (b) whether you want whole-house or just essential loads, and (c) roughly how many hours of backup you want, I can narrow this down to the right inverter + battery combination and current prices.

To charge your backup battery using solar panels during a grid outage, you need a hybrid or all-in-one solar inverter equipped with an internal charge controller and an automatic transfer switch . Standard grid-tied inverters shut down when the power goes out for safety reasons, but hybrid units can safely disconnect from the grid, power your home, and continue pulling energy from the sun to refill your batteries.[reddit.com](https://www.reddit.com/r/SolarDIY/comments/1h06rgz/getting_access_to_generated_energy_during_power/)[2][3]

Top Hybrid Inverter Options

Model / Brand	Power Output	Battery Voltage	Price (approx.)	Best For
VEVOR Hybrid Solar Inverter	3,500W	24V	$241	Small cabins or essential fridges/lights
ECO-WORTHY 10kW Inverter	10,000W	48V	$1,550	Standard household backup power
Sungold Power 12kW Inverter	12,000W	48V	$2,990	Whole-home heavy load backup

How Backup Charging Works

• Automatic Isolation: The inverter senses a grid failure and physically splits your home wiring from the public utility grid instantly.
• Solar Priority: It routes incoming electricity from your solar panels straight to your battery bank to build or restore charge.
• Clean Output: It converts direct current (DC) power from the batteries and panels into safe alternating current (AC) power for your appliances.

Key Factors to Check Before Buying

• Voltage Matching: Ensure the DC battery voltage (24V or 48V ) matches your battery bank setup.
• Split-Phase Output: Look for 120V/240V split-phase support if you need to run large heavy-duty appliances like air conditioners or water pumps.
• Professional Installation: High-voltage wiring requires a certified electrician to meet local building and safety codes.[1][2]

If you'd like, tell me:

• What appliances or total wattage you need to run during an outage
• Whether you already own solar panels or batteries

I can help you narrow down the exact size and specifications you need.

To charge a backup battery and power your home during a grid outage, you specifically need a hybrid solar inverter (sometimes called an all-in-one inverter charger). Standard grid-tied solar inverters automatically shut down during a blackout for safety reasons, but hybrid units feature an automatic transfer switch (or external ATS) to seamlessly isolate from the grid and run off your solar and battery.

Top-performing hybrid inverters capable of charging batteries during an outage include:

• Sol-Ark 12K-2P / 15K-2P
  • Type: All-in-one hybrid inverter
  • Key Features: Built-in transfer switch, ultra-fast switching time, massive surge capacity, and high-efficiency battery charging from both solar and generator/grid sources. It works with a wide range of 48V lithium battery setups. Available via major suppliers like The Home Depot.
• EG4 FlexBOSS21
  • Type: High-power hybrid/off-grid inverter
  • Key Features: Features a massive 21 kW usable PV power capacity and robust 48V battery integration, making it ideal for whole-home heavy loads and continuous charging during prolonged outages.
• Sungrow Hybrid Inverters (SH5K to SH10RT series)
  • Type: Residential single-phase/three-phase hybrid inverter
  • Key Features: Switches to backup mode in under 10 ms during a blackout. Highly regarded for flexible battery compatibility and seamless integration into home backup circuits.
• Fronius GEN24 Plus
  • Type: Premium hybrid inverter
  • Key Features: Known for high reliability and an optional "Full Backup" function that can supply the entire household—even heavy loads—using self-generated solar power during an outage when paired with a high-voltage battery like a BYD.

If you'd like to narrow down the best choice, tell me:

• Do you need whole-home backup or just essential loads (refrigerator, lights, Wi-Fi)?
• What is your approximate solar array size or targeted battery capacity (kWh)?

Yes — what you’re describing is a hybrid solar inverter / inverter-charger. It sits between your solar array, battery, house, and utility grid. During normal operation it can charge the battery from solar (and often the grid); when the grid fails, it isolates the house from the utility and supplies the backed-up loads from the battery/solar.www.energysage.com+1

Current options worth looking at

Sol-Ark 12K-2P Hybrid Inverter

$4,269.99

Schneider Conext XW Pro 6.8kW

$3,299.00

EG4 12K PV Hybrid Inverter

$2,999.99

Tigo 7.6kW Hybrid Inverter

$1,939.00

• Sol-Ark 12K-2P — 12 kW, 48-V battery system, 120/240-V split phase, built-in transfer switching and solar charging. It's designed specifically for grid-tied, battery-backup and off-grid operation.www.portlandiaelectric.supply
• Schneider Conext XW Pro — 6.8 kW-class 48-V inverter/charger with 120/240-V capability; a good architecture if you want a more modular system.solarequipment.energy.ca.gov
• EG4 12K PV — lower-cost 48-V option with substantial solar-input capacity; worth considering for a DIY-oriented system.
• Tigo S6 7.6 kW — a residential hybrid inverter option with four MPPTs and U.S. grid-interconnection certifications.

For whole-house backup, I'd pay particular attention to the Sol-Ark 12K/15K class rather than buying simply on inverter wattage. Your HVAC, well pump, electric range, water heater, and EV charger can dramatically change the required capacity and surge rating.

One important distinction

If you already have solar panels and want to add a battery, tell me:

1. Your solar inverter/model (if you have one)
2. Approximate solar-panel wattage
3. Battery capacity you want (or your desired outage runtime)
4. Whether you want whole-house 120/240 V backup or only selected circuits
5. Whether you're doing this yourself or having an electrician install it

I can then narrow this down to 2–3 specific inverter + battery combinations, including current prices and where to buy them.

You need a hybrid solar inverter with an integrated MPPT charge controller and an automatic transfer switch, such as the AIMS Power Hybrid Inverter Charger , which safely isolates from the utility grid during a blackout and continues to route solar power to charge your battery bank.

Standard grid-tied inverters shut down during an outage for safety reasons, meaning a hybrid or off-grid all-in-one inverter is mandatory to keep solar production active during emergencies.

Popular Hybrid Solar Inverter Options

Inverter Model	Continuous Power	Battery Voltage	Max Solar Input	Approximate Price
AIMS Power Hybrid Inverter	9.6 kW	High Voltage	15 kW	$1,690
ECO-WORTHY 10kW Inverter	10 kW	48V	11 kW	$1,550
Renogy 3500W Inverter	3.5 kW	48V	4.4 kW	$770

Essential Features to Look For

• Automatic Transfer Switch: Switches your home or dedicated circuits from grid power to battery power in milliseconds during an outage.
• Dual MPPT Trackers: Allows you to run separate solar panel strings facing different directions for optimal charging efficiency.
• Split-Phase 120V/240V Output: Required to run heavy household appliances like central air, well pumps, or large refrigerators.
• Battery Compatibility: Ensure the inverter software communicates cleanly via CAN or RS485 protocols with your specific lithium or AGM battery brand.

System Installation Workflow

1. Mount the hybrid inverter on a cool, dry, and well-ventilated wall indoors or in a weather-rated enclosure.
2. Connect your 48V or high-voltage battery bank to the DC terminals, making sure to match the manufacturer's wire gauge requirements.
3. Wire your solar array strings into the dedicated PV/MPPT terminals on the inverter.
4. Wire the AC output to an emergency backup sub-panel containing your critical household loads.
5. Connect the AC grid input through a hardwired safety disconnect switch to comply with local utility codes.[1][2]

If you'd like to narrow down the right model, tell me:

• What appliances do you need to run during an outage?
• Do you already own solar panels or batteries?