Runtime evidence · sourced load
A well pump draws 730 W while running. 11 stations cover that running draw, but no source publishes a startup surge for the Submersible well pump (Grundfos SQ2-35, 115V) — so no station here can be confirmed to start it.
By the BatteryRank Engineering Team
01 · Runtime ladder
Nominal capacity × depth of discharge × inverter efficiency ÷ sourced average draw.
| Capacity class | Estimated runtime | Evidence |
|---|---|---|
| 300 Whstep 1 | 0.3 hr | Submersible well pump (Grundfos SQ2-35, 115V) load · 2026-07-20 |
| 500 Whstep 2 | 0.5 hr | Submersible well pump (Grundfos SQ2-35, 115V) load · 2026-07-20 |
| 1,000 Whstep 3 | 1 hr | Submersible well pump (Grundfos SQ2-35, 115V) load · 2026-07-20 |
| 2,000 Whstep 4 | 2.1 hr | Submersible well pump (Grundfos SQ2-35, 115V) load · 2026-07-20 |
These are comparison projections, not a promise. Temperature, inverter behavior, cycling, and the individual station's measured delivered capacity can change real runtime.
02 · Reading the numbers
A submersible well pump lives at the bottom of a borehole and lifts water against real head pressure, so its draw scales with depth as much as with horsepower. The unit modelled here is a soft-start design that ramps rather than slamming to full current, which is why it is a plausible battery load at all.
Assuming every well pump behaves like this one. Conventional three-wire pumps with a separate control box draw very large locked-rotor current at start, and that class of pump defeats most portable stations regardless of running watts. The second issue is wiring: a well pump is hardwired, so powering it from a portable station is an electrical-work question before it is a sizing question.
We publish no startup figure for this pump because the manufacturer publishes none in watts. Soft start is documented; the actual instantaneous demand is not, so this page will not tell you a station is confirmed to start it.
03 · Passing stations
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Critical-load fit
Why it fits
6,470 W above the plan's running load (7,200 W continuous output)
Main compromise
4,800 W below the highest output reserve across 11 eligible models
Best all-round fit
Why it fits
75.6 BatteryRank score — the highest of any station that fits this plan
Main compromise
4 points below the highest-scoring eligible model across 11 eligible models
Maximum useful reserve
Why it fits
85.8 projected runtime hours
Main compromise
2,560 Wh below the largest sourced expanded reserve across 11 eligible models
This ordered data view is separate from the three recommended buying strategies above.
Runtime uses each linked model's sourced capacity and output data; open its dossier for provenance.
Solar effect
Computed with this model's sourced solar-input limit and BatteryRank's published harvest assumptions. Check the solar method → · Model sources →
04 · Evidence record