Best Battery Backup for Sump Pumps in 2026
Updated July 2026 Ranked by computed spec math, never by commission. How we rank
How we ranked these
Sump pumps are a surge problem first and a capacity problem second. We ranked by motor-start surge headroom, then by runtime at a realistic 20% storm duty cycle (pump runs 12 minutes per hour), then UPS switchover - because the outage and the storm arrive together.
Top pick
#1 — EcoFlow Delta Pro 3
4,096Wh · 4,000W (6,000W surge) · 240V · 4,000 cycles · 114 lb · $3,699 MSRP
≈ 4 hours for this use case (Sump pump 1/3 HP (800W run, 2,000W start, 20% duty), 85% inverter efficiency).
Triple the surge headroom a 1/3 HP pump needs, 20+ hours of storm duty, and it doubles as whole-home essentials backup the other 360 days a year.
Big-storm pick
#2 — Anker SOLIX F3800 Plus
3,840Wh · 6,000W (9,000W surge) · 240V · 3,000 cycles · 132 lb · $4,799 MSRP
≈ 4 hours for this use case (Sump pump 1/3 HP (800W run, 2,000W start, 20% duty), 85% inverter efficiency).
6,000W/9,000W handles a 1/2 HP pump plus a fridge simultaneously; expandable to 26.9kWh for multi-day flood events. Frequently discounted.
Budget pick
#3 — Jackery Explorer 2000 v2
2,042Wh · 2,200W (4,400W surge) · 4,000 cycles · 39 lb · $1,499 MSRP
≈ 2 hours for this use case (Sump pump 1/3 HP (800W run, 2,000W start, 20% duty), 85% inverter efficiency).
4,400W surge starts a 1/3 HP pump, and 2kWh covers ~12 hours at storm duty for around $1,100. Not expandable - fine for short outages.
Side-by-side
| Pick | Capacity | Output / surge | 240V | Cycles | Weight | MSRP | Runtime* |
|---|---|---|---|---|---|---|---|
| EcoFlow Delta Pro 3 | 4,096 Wh | 4,000 / 6,000 W | Yes | 4,000 | 114 lb | $3,699 | 4h |
| Anker SOLIX F3800 Plus | 3,840 Wh | 6,000 / 9,000 W | Yes | 3,000 | 132 lb | $4,799 | 4h |
| Jackery Explorer 2000 v2 | 2,042 Wh | 2,200 / 4,400 W | No | 4,000 | 39 lb | $1,499 | 2h |
*Runtime for Sump pump 1/3 HP (800W run, 2,000W start, 20% duty) at 85% inverter efficiency. Your load differs — size it exactly.
Frequently asked questions
What size battery backup do I need for a 1/3 HP sump pump?
A 1/3 HP pump runs at ~800W and surges to ~2,000W at motor start. You need an inverter rated above 2,000W surge, and about 190Wh of battery per hour of storm operation at a typical 20% duty cycle.
How long will a power station run a sump pump in a storm?
At a 20% duty cycle (pump cycling 12 min/hour), a 4,096Wh EcoFlow Delta Pro 3 runs about 21 hours; a 2,042Wh Jackery 2000 v2 about 10.5 hours. Continuous heavy inflow cuts those numbers to a fifth.
Is a dedicated 12V sump backup better than a power station?
Dedicated 12V backup pumps (e.g., Zoeller Aquanot) are cheaper per hour of pumping but do only one job. A power station costs more but backs up the pump, fridge, phones, and Wi-Fi at once - and works year-round for other outages.