The EcoFlow DELTA 2 Max is a 2,048Wh, 2,400W expandable power station suited to home backup, RV trips, workshops, and larger off-grid loads. Its two solar inputs accept up to 1,000W combined, and two compatible extra batteries can raise storage to 6,144Wh. At about 50lb, it makes more sense for vehicle-based use than frequent hand carrying. Check the exact unit, bundle, and seller before buying because EcoFlow’s current page shows changing availability across selections.
This guide is based on EcoFlow’s specifications and manual, not hands-on testing of the DELTA 2 Max. Charging times and cycle life are manufacturer figures; runtime examples are planning estimates. Our testing methodology explains how we distinguish research from measurements.
Key Takeaways
- A 2,400W continuous inverter and 2,048Wh battery cover many essential loads, but appliance startup draw and actual energy use determine what runs and for how long.
- The 3,400W X-Boost mode can help with some compatible appliances; it does not turn the inverter into a 3,400W continuous supply for every device.
- Two 500W solar inputs give you flexibility when sizing panels. Each input has its own 11–60V and 15A limits, so check the whole array before connecting it.
- One or two compatible smart extra batteries increase storage to 4,096Wh or 6,144Wh. They do not raise the base station’s 2,400W continuous AC output.
- Fast wall charging and expansion are compelling if the current offer is competitive, but verify the selected configuration, shipping status, warranty, and total accessory cost.
Product Overview Table
These ratings apply to the U.S. DELTA 2 Max, model EFD350. Charging and transfer times are published figures under specified conditions, not measurements from Pure Power Solar.
| Feature | U.S. DELTA 2 Max (EFD350) |
|---|---|
| Battery capacity | 2,048Wh LiFePO4 |
| Continuous AC output | 2,400W pure sine wave, six outlets |
| Surge output | 4,800W short-duration rating |
| X-Boost | Up to 3,400W with compatible loads |
| Cycle life | 3,000 cycles to at least 80% capacity |
| Extra batteries | Up to two compatible smart extra batteries |
| Maximum expanded capacity | 6,144Wh with two 2,048Wh extra batteries |
| AC input | Up to 1,800W; about 80 minutes in manual |
| Solar input | Two × 500W; 1,000W total |
| Solar electrical limits | 11–60V and 15A per input |
| Vehicle input | 12V or 24V battery; 8A default |
| EPS transfer | Within 30ms; not zero-transfer UPS |
| Weight | Approximately 50lb (23kg) |
| Dimensions | 19.6 × 9.5 × 12in |
| Connectivity | Wi-Fi and Bluetooth |
| Warranty | Five years advertised by EcoFlow |
Performance
EcoFlow DELTA 2 Max Portable Power Station
from: EcoFlow
Six AC outlets share a 2,400W continuous pure-sine-wave inverter. That is the figure to use when adding the running draw of a refrigerator, microwave, coffee maker, tools, TV, or other simultaneous loads. The 4,800W surge rating describes short startup demand; a motor or compressor still needs device-specific checks.
X-Boost supports some compatible appliances up to a stated 3,400W. It can change output behavior and is more suitable for heating devices than equipment with strict voltage requirements. The manual says it is unavailable while AC output is in bypass mode during recharging. Use the ordinary 2,400W rating for sensitive electronics and any load you have not verified with X-Boost.
Battery & Specs
The 2,048Wh battery uses LiFePO4 chemistry. EcoFlow rates it for 3,000 cycles to at least 80% of original capacity. That threshold describes retained capacity, not an expiry date; temperature, depth of discharge, storage, and charge habits affect real aging. Read the battery cycle-life guide for what the rating means.
The DELTA 2 Max accepts up to two smart extra batteries. EcoFlow’s U.S. specifications name both the DELTA 2 Max Smart Extra Battery and DELTA Max Smart Extra Battery as supported options; confirm the exact accessory and connection cable for the unit you are buying. One 2,048Wh extra battery brings the system to 4,096Wh, and two bring it to 6,144Wh. Extra storage lengthens potential runtime but does not increase the inverter’s 2,400W continuous rating.
Estimating runtime
Nameplate battery capacity is not the same as usable AC energy. For a simple estimate, multiply 2,048Wh by an assumed usable fraction and divide by the appliance’s average wattage. At an assumed 85% usable AC energy, a steady 500W load would run for about 2,048Wh × 0.85 ÷ 500W ≈ 3.5 hours. This is not a measured result; refrigerator duty cycle, inverter overhead, settings, temperature, and battery age can change it. Try the portable power station runtime calculator with your own load.
Portability & Design
EcoFlow DELTA 2 Max Portable Power Station
from: EcoFlow
EcoFlow DELTA 2 Max Portable Power Station
from: EcoFlow
At approximately 50lb and 19.6 × 9.5 × 12in, the DELTA 2 Max is movable by its side handles but awkward for frequent solo carries. It works best when you can place it near the loads and move it mainly by vehicle. The built-in screen shows battery level and power flow, while Wi-Fi and Bluetooth allow monitoring and settings through the EcoFlow app. Basic power-station operation does not require the app.
Charging Options
AC charging
The manual specifies up to 1,800W AC input and shows about 80 minutes for AC charging. Use the supplied cable and a suitable wall outlet as directed; the AC charging speed switch and app settings can change input power. Starting charge, temperature, battery protection, and loads in use affect actual time. Do not confuse this AC-only figure with an AC-plus-solar promotional claim.
Solar charging
There are two solar inputs, each rated for up to 500W at 11–60V and 15A, for 1,000W total. A full charge may take much longer than a best-case marketing figure because panel output changes with sunlight, shade, angle, temperature, and battery state. Check each array’s cold-weather open-circuit voltage, operating voltage, current, wattage, connector, and polarity. The solar panel sizing guide for power stations can help you plan both inputs.
AC and solar together
The DELTA 2 Max can combine AC and solar for faster charging when both sources and settings permit it. Faster combined charging depends on the starting charge, solar production, AC setting, and temperature. Compare any quoted time against those conditions before planning your setup.
Vehicle and generator charging
The supplied vehicle cable supports 12V or 24V battery systems at the manual’s specified current. A compatible generator can supply the normal AC input if it meets the station’s requirements. Follow both sets of instructions and operate any fuel-burning generator outdoors, away from doors, windows, and vents.
Pass-through power and EPS
The manual describes EPS transfer to battery power within 30ms during a grid outage. That is not a zero-transfer UPS, and compatibility depends on the connected device. In bypass mode, wall power supplies the connected AC loads while the station charges. Test noncritical equipment first, and do not assume this setup is appropriate for devices requiring uninterrupted power.
Price & Value
Compare the price of the exact 2,048Wh base unit against other 2kWh-class stations with similar inverter and solar limits. Prices change frequently, so compare the current total for the configuration you actually need. EcoFlow’s page currently shows a mix of pre-order and sold-out messaging for different selections, so check the selected model, shipping date, seller, return terms, and warranty at checkout.
An extra battery or solar bundle may suit you, but compare total system cost and included cables and panels. If you only need occasional small-device charging, a lighter station could be better value. If you need 2,400W output, up to 1,000W solar input, and storage that can grow, the DELTA 2 Max remains a practical option when available on clear terms.
Ideal Use Cases
- Home backup: run selected refrigerators, freezers, routers, lights, and other essentials after checking their combined draw and startup needs.
- RV and van setups: use the dual solar inputs and vehicle-based transport where the roughly 50lb weight is manageable.
- Workshops and mobile jobs: power tools that fit the 2,400W continuous and startup limits.
- Preparedness and off-grid systems: add compatible battery capacity when you need more stored energy between recharges.
- Basecamp use: favor capacity and charging flexibility over lightweight carrying.
Pros and Cons
Pros
- 2,048Wh LiFePO4 battery with expansion to 6,144Wh using two compatible extra batteries.
- 2,400W continuous AC output, six outlets, and two solar inputs rated for 1,000W total.
- Up to 1,800W AC charging, app monitoring, and a five-year warranty advertised for eligible purchases.
Cons
- About 50lb is a lot to carry often, and extra batteries add weight and cost.
- X-Boost is conditional; EPS transfer is not a zero-interruption UPS.
- Selected bundles and shipping status can vary, so a current offer needs careful checking.
Final Verdict
The DELTA 2 Max remains a useful choice for home backup, RV power, workshops, and off-grid setups when you need a strong 2,400W inverter, two solar inputs, and room to expand storage. Choose it if the exact EFD350 unit and any accessories you need are available from a seller with clear terms. A lighter model may fit frequent carrying better, while a dedicated UPS is a better match for equipment that cannot tolerate a transfer delay.
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Compare Against Alternatives
Still deciding on EcoFlow Delta 2 Max? Start with these head-to-head comparisons:
- EcoFlow Delta 2 Max vs EcoFlow Delta 1300
- EcoFlow Delta 2 Max vs EcoFlow Delta Pro
- EcoFlow Delta 2 Max vs Jackery Explorer 2000 Plus
For a broader brand overview, see: EcoFlow vs Jackery.
FAQs
How long does the DELTA 2 Max last on a full charge?
It depends on the average load. A steady 500W AC load works out to roughly 3.5 hours using the 85% planning assumption above. A refrigerator cycles, so its actual runtime can differ considerably; use measured energy consumption if available.
Can I use the EcoFlow DELTA 2 Max while charging?
Yes, it supports pass-through operation, subject to the manual’s input and output limits. During AC bypass, connected AC devices are supplied by the wall source. That does not make the EPS function a zero-transfer UPS.
Is the EcoFlow app required to use it?
No. The station can power devices without the app, while the app adds remote monitoring, charging settings, and firmware functions.
What solar panels work with the DELTA 2 Max?
Use panels or arrays that stay within each input’s 11–60V, 15A, and 500W limits, with no more than 1,000W across both inputs. Check cold-weather open-circuit voltage, wiring, connector, and polarity—not just the panels’ advertised wattage.
Which extra batteries can it use?
EcoFlow’s U.S. specifications list the DELTA 2 Max Smart Extra Battery and DELTA Max Smart Extra Battery. Confirm the exact accessory, cable, and supported configuration before ordering. Up to two additions raise total capacity to 6,144Wh; AC output remains 2,400W.
Last update on 2026-10-15 / Affiliate links / Images from Amazon Product Advertising API