In short
It's a draw on our six scenarios, so price decides: the Anker SOLIX F3800 Plus costs $399.01 less. The real difference is what they can start: electric water heater, 50 gal (F3800 Plus only), window ac, 12,000 btu (DELTA Pro 3 only).
We may earn a commission if you buy through links on this page, at no extra cost to you. It never changes a result. Specs from each maker, prices checked October 28, 2026; we haven't tested these units.
Anker SOLIX
6,000 W at 240 V runs a well pump and most circuits through a transfer switch; six expansion batteries per unit.
$2,399.99after on-site coupon, October 28, 2026
Check price
EcoFlow
4 kWh with 120/240 V; grows to 12 kWh per unit. EcoFlow's Smart Generator can top it up on long outages.
† reported by retailers or reviews, not yet confirmed on EcoFlow's spec sheet.
$2,799list $3,299 · out of stock when checked, October 28, 2026
Check priceEach starts at 6 p.m., battery only. Extra batteries are added when the maker sells them and the outage needs them.
| Scenario | F3800 Plus | DELTA Pro 3 | Better pick |
|---|---|---|---|
| Fridge, Wi-Fi & lights24 h | 24 h+ | 24 h+ | Tie |
| Storm night + sump pump48 h | 2.0 days+ (+2 batt.) | 2.0 days+ (+2 batt.) | Tie |
| CPAP + fridge24 h | 24 h+ | 24 h+ | Tie |
| Rural: well pump & freezer72 h | 3.0 days+ (+3 batt.) | 2.7 days (+2 batt.) | F3800 Plus |
| Winter: gas furnace72 h | 46 h (+6 batt.) | 21 h (+2 batt.) | DELTA Pro 3 |
| Hurricane week168 h | Can't start your biggest motor | Not enough continuous output | Tie |
| Spec | Anker SOLIX F3800 Plus | EcoFlow DELTA Pro 3 |
|---|---|---|
| Battery | 3.8 kWh LFP | 4.1 kWh LFP |
| Expandable to | 27 kWh | 12 kWh |
| Continuous output | 6.0 kW | 4.0 kW |
| Start-up surge | not published | 8.0 kW |
| 240 V | Yes | Yes |
| Solar input | 3.2 kW | 2.6 kW |
| Weight | 136.7 lb | 113.5 lb |
| Warranty | 5 years | 5 years |
| Panel connection | Home Power Panel or manual 10-circuit transfer switch | Smart Home Panel 2 (installed) |
| Price | $2,399.99 | $2,799 |
Appliances only one of them can start on its own: Electric water heater, 50 gal (F3800 Plus), Window AC, 12,000 BTU (DELTA Pro 3).
It's a draw on our six scenarios, so price decides: the Anker SOLIX F3800 Plus costs $399.01 less. Scenario by scenario results are in the table on this page; they come from published specs, not hands-on tests.
The Anker SOLIX F3800 Plus can, for about 3.2 days on one charge. The EcoFlow DELTA Pro 3 can, for about 3.4 days on one charge.