Before you spend a dollar on a solar generator to back up your well, read this one paragraph, because it will save you from the most expensive mistake people make here. Most residential deep-well pumps are 240 volt. Most portable power stations, including big, expensive ones, output 120 volt. A 120V source physically cannot run a 240V pump. It is not a matter of being a little underpowered. The motor will not turn. So the first question is not “how big a battery do I need,” it is “is my pump 120V or 240V,” and only a handful of units on the market can run the 240V kind.
Here is how the two camps break down. A submersible pump sitting down in a drilled well is almost always 240 volt and needs a 240V-capable source. A shallow-well jet pump, the kind that sits above ground in a basement or pump house, is often 120 volt and can be run by a large normal power station. Check the nameplate on your pressure switch box or control box, or your well driller’s report, before buying anything. If it says 230V or 240V, you are in the first camp.
The good news is that a battery solar generator is genuinely the nicest way to back up a well if you get the right one. It is silent, it lives indoors, it makes no exhaust, and paired with a solar panel it recharges itself during a long outage. The catch is that a 240V-capable unit with enough surge to start a pump is a real investment. Below are the units that can actually do the job, split by what kind of pump you have.
Sizing: Why You Buy for the Surge, Not the Run
A pump motor pulls a big spike of current the instant it starts, far higher than what it draws while running. If your power source cannot handle that surge, it trips and shuts off the moment the pump kicks on, even though it looked big enough on paper. So you size for the startup surge.
Rough figures, and these are approximate, so confirm against your pump’s amp rating:
- A 1/2 HP submersible pump pulls roughly 960 watts running and can surge to around 1,900 to 2,900 watts on startup.
- A 3/4 HP pump runs around 1,320 watts and surges to roughly 2,600 to 4,000 watts.
- A 1 HP pump runs around 1,900 watts and can surge to 3,800 to 5,800 watts or more.
The practical takeaway: aim for a unit that can deliver 4,000 to 5,000 watts of surge to cover a typical residential pump with margin. That is why the dedicated 240V units below are large. A small power station will run your lights and fridge but will stall a well pump.
EcoFlow DELTA Pro 3
If you have a 240V deep well and you want one box that runs it, the DELTA Pro 3 is the pick. It is one of the few power stations that outputs native 240 volt from a single unit, with no accessory hub and no second battery required. It has a true 240V outlet (L14-30) plus standard 120V outlets, so it can drive a 240V pump directly. EcoFlow has demonstrated it running a 240V well pump in its own testing.
The numbers back up the job. The battery is 4096Wh, output is 4000 watts continuous with a 6000-watt X-Boost surge, which is comfortably above the surge of a typical residential pump. It is expandable to 48kWh with extra batteries, so for a long outage you can keep adding runtime, and it pairs well with solar to recharge during the day.
The honest downsides are weight and price. At roughly 115 pounds it is not something you casually carry, so plan a permanent spot for it. And it is a high-end purchase. But for backing up a 240V well from a single, silent, indoor-safe unit, nothing simpler does it.
Anker SOLIX F3800
The SOLIX F3800 is the other single-unit 240V option, and it is the one to get if you want the biggest surge margin. It outputs native 240 volt from one unit through a NEMA 14-50 and an L14-30 outlet, and it pushes 6000 watts continuous with a 9000-watt surge. That is more headroom than almost any residential pump will ever ask for, including a 1 HP pump with a hard startup, which makes it the most foolproof choice for someone who is not certain of their pump’s exact draw.
The battery is 3840Wh and expandable to around 27kWh, so like the DELTA Pro 3 it scales for a multi-day outage and works with solar. With its high output it can also comfortably run the pump alongside a fridge, a furnace blower, and lights at the same time, which a smaller unit cannot.
The trade-off is size. At about 132 pounds it is the heaviest unit here and genuinely bulky, so it wants a dedicated location and is not moving around the property easily. If your pump is on the larger side or you want zero risk of a surge trip, that weight buys you certainty.
EcoFlow DELTA Pro (Original)
The original DELTA Pro is a 120V workhorse, and it earns a spot for two reasons. First, if you have a shallow-well or 120V jet pump, its 3600Wh battery and 3600-watt output (4500-watt X-Boost) will run it with plenty of capacity to spare. Second, it is the on-ramp to a 240V system: a single DELTA Pro is 120V, but two of them bonded through EcoFlow’s Double Voltage Hub produce 240 volt at higher wattage, so you can start with one unit for general backup and add the second unit plus the hub later when the budget allows.
For a household that wants a big, expandable battery (it scales to 25kWh) for outages generally, and only sometimes needs 240V, this staged path makes sense. You are not wasting the first purchase.
Be clear-eyed about the 240V part, though. Reaching 240 volt this way means buying two large DELTA Pros plus the hub, which lands well above the single-unit DELTA Pro 3 in total cost. If your only goal is to run a 240V well today, the DELTA Pro 3 or SOLIX F3800 is the simpler and usually cheaper route. The original DELTA Pro is the smart pick when 120V loads (or a 120V pump) are the main job.
Bluetti AC500 + B300S
The AC500 paired with a B300S battery is the modular powerhouse. The inverter head pushes 5000 watts continuous with a 10,000-watt peak surge, which is the most surge capacity of anything here, and the battery is part of a system you can keep expanding tray by tray. For someone backing up a larger home where the well pump is one of several big loads, this is the platform that grows with you.
Like the modular Bluetti systems generally, reaching true 240 volt is a two-unit build: you run two AC500s through a Bluetti Fusion Box to get split-phase 240V at 7200 watts or more, with a 50A (14-50) output. A single AC500 is 120V. So this is the pick when you are committing to a serious, expandable home-backup system, not the cheapest way to run one pump.
The weight is the obvious cost, around 146 pounds with one battery, and a two-unit 240V setup is a permanent installation, not a portable kit. If you want the most surge and the most expansion room and you are building a whole-home-leaning backup, this is the modular choice.
Bluetti AC200L
The AC200L is the value pick, with one big caveat: it is 120 volt only, so it cannot run a 240V deep-well pump. What it can do, and do very well for the money, is run a shallow-well or 120V jet pump and the rest of your essentials. It has a 2048Wh battery, 2400 watts of output with a 3600-watt lifting surge that is enough to start a 1/2 to 3/4 HP 120V pump, a 30A output, and a dozen ports. It is also expandable to 8192Wh.
At roughly 62 pounds it is far more manageable than the big 240V units, and it costs a fraction of what they do. If you have confirmed your pump is 120V, this is the most sensible amount of money to spend. If your pump is 240V, the AC200L is the wrong tool no matter how good the value, so do not let the price tempt you into it.
How We Picked These
Backing up a well is a narrower problem than general outage backup, so the criteria are specific:
Voltage match. The first cut is whether a unit can run a 240V pump at all. We separated the native-240V single units, the two-unit 240V builds, and the 120V-only units that suit shallow pumps, so you buy the right camp for your pump.
Surge capacity. A pump trips a source that cannot handle its startup spike. We favored units with enough surge headroom (roughly 4,000 watts and up) to start a typical residential pump.
Battery and expandability. A well backup is most useful if it lasts a real outage and recharges from solar. We weighted battery size and how far each unit expands.
Honesty over hype. We did not list small power stations as well-pump solutions just because they are popular. A unit that stalls the pump is not a well-pump generator, whatever the marketing says.
Frequently Asked Questions
Before You Buy
A solar generator is one piece of a well backup plan. The strategy around it matters as much as the unit:
- Well pump backup power. The full breakdown of generators, hand pumps, stored water, and the fill-then-shut-off trick.
- What size power station do I need. How to add up running and surge watts for your whole setup.
- Best portable power stations. The general backup roundup for fridges, lights, and smaller loads.
If your pump is 120V, you may not need a unit this large, so it is worth sizing your actual loads before committing to the high-end units here.
Bottom Line
If you have a 240V deep well and want one unit to run it, the EcoFlow DELTA Pro 3 is the cleanest answer, with native 240V output from a single box. If you want the biggest surge margin so you never worry about a trip, step up to the Anker SOLIX F3800. Building a larger, expandable home-backup system? The Bluetti AC500 modular setup gives you the most surge and the most room to grow.
If your pump is a shallow-well or 120V jet pump, you do not need the big 240V units at all. The Bluetti AC200L runs it for far less money, and the original EcoFlow DELTA Pro gives you a larger battery and a path to 240V later. Whatever you buy, confirm your pump’s voltage off the nameplate first. That one number decides everything.