Premium Pick · Battery

EcoFlow DELTA Pro 3 Review

4kWh, 4,000W, and 120/240V from a single unit — the first battery that fully replaces a generator for most homes.

9.2
/ 10
EcoFlow DELTA Pro 3

The verdict

The DELTA Pro 3 fixes its predecessor's one structural gap: 240V output from a single unit, which means it can feed a transfer switch and run well pumps, dryers, and other 240V loads no other solo battery touches. Add 4,096Wh of quieter-than-a-whisper LFP capacity, 4,000W output, and expansion headroom, and this is the battery to buy when the battery IS the backup plan.

Typical price: ~$2,399 (typical street price — current price shown on Amazon)

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What we like

  • +120/240V dual-voltage output from one unit — feeds a transfer switch directly
  • +4,000W continuous handles essentially every household appliance
  • +4,096Wh LFP base, expandable with extra batteries for multi-day capacity
  • +Fast recharging: wall, generator, or up to 2,600W of solar
  • +Sub-20ms UPS switchover; wheels + extending handle for its 100+ lb

What to know

  • Serious money — and expansion batteries add four figures more
  • 115 lb: mobile on wheels, memorable on stairs
  • For pure $/Wh, the original DELTA Pro on sale is the better deal

Full review

The original DELTA Pro's asterisk was always 240V: powering a well pump or a transfer-switch-fed panel took two units and a combiner box. The Pro 3 deletes the asterisk — one machine, dual-voltage output, plug it into a compatible transfer switch inlet and your panel's essential circuits run on silent battery power. That single change moves battery backup from 'extension cords for the fridge' to genuine infrastructure.

Everything else got the generational bump: more capacity, more output, faster solar charging, quieter fans, and a sub-20ms UPS mode that keeps computers and CPAPs from even noticing an outage. Paired with solar panels or a small generator for daily recharging, it will carry a home's essentials indefinitely.

Buy it over the original DELTA Pro if 240V loads, UPS behavior, or maximum solar input matter to you. If they don't, the original at its frequent $1,500-class sale price remains the category's value king — and that comparison is exactly why we keep both in the lineup.

Best for: Homes committed to silent, fuel-free backup — especially those with 240V loads like well pumps.

Specifications

Capacity4,096Wh (LFP, expandable)
AC output4,000W continuous, 120/240V dual voltage
OutletsMultiple AC incl. 240V, USB-C, 12V
Solar inputUp to 2,600W
UPS switchover<20 ms
Cycle life4,000 cycles to 80%
Weight~115 lb
Warranty5 years

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~$2,399 typical price

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