The EcoFlow capacity you need depends on two numbers: the total watt-hours (Wh) your devices use over the time you need power, and the highest wattage (W) you will run at once. As a rough guide, River models suit phones, laptops and small camping loads, Delta models cover a fridge and essentials during an outage, and the Delta Pro range is aimed at longer home backup.
Quick answer: Add up the watts of what you want to power, multiply by the hours you need, and add a margin of roughly 15 to 20 percent for conversion losses. Under about 300 Wh, a River is usually enough; around 1,000 Wh suits most weekend camping and short outages; 2,000 Wh and up is for longer backup or heavier appliances.
Watt-hours vs watts: the two numbers that matter
Every power station lists two key specs, and confusing them is the most common sizing mistake.
- Capacity (Wh): how much energy is stored. A 1,024 Wh unit could in theory run a 100 W device for about 10 hours, before losses.
- Output (W): how much power it can deliver at once. A device that draws more than the rated output, or has a startup surge above it, will trip the inverter.
- Surge and boost modes: EcoFlow advertises features such as X-Boost, which can run some higher-wattage resistive devices at reduced power. It does not increase stored energy.
How to calculate what you need
- List your devices. Note the wattage from each device’s label or manual, not an online guess.
- Estimate hours of use for each device over the period you care about, for example one day of an outage or a two-night camping trip.
- Multiply watts by hours for each device, then add them together for total Wh.
- Add a margin. AC inverters lose some energy as heat, so plan for usable capacity to be noticeably lower than the rated figure, often by 10 to 20 percent.
- Check the peak load. Add the watts of every device that may run at the same time and make sure the station’s continuous output covers it.
Example: a laptop rated at 60 W used for 4 hours (240 Wh) plus a 10 W LED light for 5 hours (50 Wh) totals 290 Wh. With a 20 percent margin, that is about 350 Wh, which points to a River 2 Pro-class unit or larger rather than the smallest River models.
EcoFlow capacity tiers compared
The figures below are EcoFlow’s published capacities and continuous AC output for popular models as of 2026. Specs vary by version and region, so check the listing and EcoFlow’s spec sheet.
| Model | Capacity | AC output (continuous) | Good for |
|---|---|---|---|
| River 3 | 245 Wh | 300 W | Phones, cameras, lights, a laptop |
| River 3 Plus | 286 Wh | 600 W | Day trips, small camp loads |
| River 2 Pro | 768 Wh | 800 W | Weekend camping, a laptop workday |
| Delta 3 Plus | 1,024 Wh | 1,800 W | Fridge and essentials in an outage, RV use |
| Delta 2 | 1,024 Wh | 1,800 W | Similar to Delta 3 Plus, older generation |
| Delta 2 Max | 2,048 Wh | 2,400 W | Longer outages, power tools |
| Delta Pro 3 | 4,096 Wh | 4,000 W | Home backup, heavier appliances |
Several Delta and Delta Pro models accept extra batteries to expand capacity. Check which expansion batteries are compatible with the exact model before buying one separately.
Matching capacity to common use cases
- Phones and small gadgets on the go: River 3 class (around 250 Wh). Compact and easy to carry.
- Camping with a laptop, lights and a small cooler: 500 to 1,000 Wh, depending on the cooler’s draw and how long you are out.
- CPAP or other medical devices: follow the device maker’s guidance and your clinician’s advice, and check the device’s watt rating and DC options. Do not rely on a single power source for essential medical equipment.
- Refrigerator during an outage: 1,000 Wh or more is a common starting point. A fridge cycles on and off, so its daily energy use depends on the model; check the label or an energy guide.
- Home backup for several circuits: 2,000 to 4,000 Wh and up, often with expansion batteries or a transfer solution installed by a licensed electrician.
Recharging: solar, wall and car
Capacity only helps if you can refill it. EcoFlow stations typically support AC wall charging, car charging and solar input, with charge speeds that vary by model.
- Wall charging: many current EcoFlow models advertise fast AC charging, which is useful before a storm.
- Solar: check the maximum solar input (in watts) and voltage range. Real solar output is often well below the panel’s rating because of weather, angle and season.
- Car charging: slow but useful on road trips.
Weight, size and portability
Capacity adds weight. Small River models can be carried in one hand, while 2,000 Wh-class units are heavy enough that wheels or a second person help. If you camp or move the unit often, buy the smallest capacity that genuinely covers your needs and add solar rather than oversizing.
Air travel is a separate issue. Portable power stations are far larger than the batteries airlines typically allow. The FAA’s guidance on lithium batteries in baggage limits spare lithium-ion batteries over 100 Wh, and allows 101 to 160 Wh batteries only with airline approval.
Buying an EcoFlow on eBay: what to check
- Exact model and version: River 3 vs River 3 Plus, Delta 2 vs Delta 3 Plus, and the region version (US and Canadian units use the same plug type).
- Battery health: EcoFlow units use LFP batteries on current models, which are designed for many charge cycles. Ask the seller for a screenshot of the cycle count or battery status in the EcoFlow app, if shown.
- Accessories: AC charging cable, car cable and solar adapter.
- App account: ask the seller to remove the unit from their EcoFlow app account.
- Physical condition: look for swelling, cracks, burn marks or a damaged display. Avoid any unit with signs of swelling or damage.
- Warranty and returns: refurbished units under eBay’s program typically include a warranty; for used units, rely on the seller’s return policy and the eBay Money Back Guarantee when you pay through eBay checkout.
You can see current EcoFlow Delta 3 Plus listings on eBay or browse EcoFlow River 3 listings on eBay.ca. If you are considering a refurbished unit, read whether refurbished electronics are worth it, and for timing tips see the best times to buy electronics on eBay.
FAQ
How long will a 1,000 Wh power station run a device?
Divide the usable capacity by the device’s wattage. For a 100 W load, a 1,024 Wh unit might deliver somewhat less than 10 hours once inverter losses are included.
Can an EcoFlow run a refrigerator?
Many Delta models can, as long as the fridge’s running and startup wattage fit within the station’s output. Runtime depends on the fridge’s daily energy use.
Is it better to buy a bigger unit or add an extra battery?
If your model supports expansion, starting smaller and adding a battery later gives flexibility. If you know you need large capacity from day one, a bigger unit can be simpler.
Can I take an EcoFlow on a plane?
Generally no. Power stations exceed the battery limits set out in the FAA’s guidance and most airline rules. Check with your airline.
Is a used EcoFlow a good buy?
It can be, if the unit shows no physical damage, the battery status looks healthy, and the listing offers returns.
Conclusion
Size an EcoFlow by your real energy use, not by the biggest number on the box. Work out watt-hours and peak watts, add a margin for losses, and pick the smallest model that covers both, with solar or an expansion battery for extra headroom.
Disclosure: tikto.store is an independent guide and an eBay Partner Network affiliate. We may earn a commission when you buy through our links, at no extra cost to you. tikto.store is not eBay and is not affiliated with eBay Inc. beyond the affiliate program.