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FIRMAN ZERO E Runtime Calculator
Quick answer: the FIRMAN ZERO E stores 1,040 Wh and delivers up to 2,000 W of continuous AC power. Under this site's planning assumptions (85% inverter efficiency, 10% reserve), a steady 100 W AC load runs for roughly 8.0 hours. Last source check: 2026-08-27. This is an estimate, not a guarantee.
Battery capacity1,040 Wh
AC output2,000 W
Surge output4,000 W
Battery chemistryLiFePO4
ConfidenceEstimated
Source regionGlobal/general sources
checked2026-08-27
Swipe table sideways
| Battery capacity | 1,040 Wh |
|---|---|
| Battery chemistry | LiFePO4 |
| AC output | 2,000 W |
| Surge output | 4,000 W |
| DC output | unknown |
| USB-C output | 100 W |
| Solar input | 400 W |
| Weight | unknown |
| Confidence | Estimated |
| Lifecycle status | Unknown |
| Source region | Global/general sources |
| Last verified | 2026-08-27 |
Catalog notes (original English)
The TT-30R outlet makes the ZERO E directly usable on a 30A RV shore-power cord, which is unusual at this capacity. FIRMAN publishes no DC output wattage or unit weight, so those stay unknown. FIRMAN's separate Zero E Expansion Power Pack +1000 is an add-on battery rather than a standalone station and is not catalogued.
Runtime estimate
Formula starting points use each scenario’s default watts, duty cycle and output path, with 10% reserve or 15% for CPAP. Linked detail pages use the same inputs. Hours apply only if the device can run and start; they are not measured runtimes.
Swipe table sideways
| Device scenario | Planning default | Estimated runtime | Device scenario: Confidence | Models |
|---|---|---|---|---|
| Full-size refrigerator | 500 W · 33% · AC inverter · Reserve: 10% | 4h 49m Within the tracked power limits; compatibility still needs checking | Estimated | Calculator |
| CPAP without heated humidifier | 40 W · 100% · AC inverter · Reserve: 15% | 18h 47m Within the tracked power limits; compatibility still needs checking | Estimated | Calculator |
| Starlink Mini | 32 W · 100% · USB-C PD · Reserve: 10% | 1d 2h Within the tracked power limits; compatibility still needs checking | Estimated | Calculator |
| Wi-Fi router | 12 W · 100% · AC inverter · Reserve: 10% | 2d 20h Within the tracked power limits; compatibility still needs checking | Estimated | Calculator |
| LED TV | 100 W · 100% · AC inverter · Reserve: 10% | 7h 57m Within the tracked power limits; compatibility still needs checking | Estimated | Calculator |
Runtime calculator
Runtime is conditional on successful startup, compatible voltage/connectors and sufficient output. Verify the actual device setup before relying on these hours.
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Power station model
Battery capacity (Wh): 1040 WhContinuous output rating (W): 2000 WSurge output rating (W): 4000 W
Estimated runtime13h 16m8h 18m – 16h 28mEstimated runtime: 13h 16m, 8h 18m – 16h 28m
Output path
Estimated runtime
Within the tracked power limits; compatibility still needs checking
This is an estimate. Real runtime changes with load, temperature, battery age, AC/DC output, and device behavior. Runtime is conditional on successful startup, compatible voltage/connectors and sufficient output. Verify the actual device setup before relying on these hours.
13h 16mEstimated runtime: 13h 16mThis setup has comfortable headroom for overnight use, assuming the wattage estimate is realistic.
Conservative8h 18m
Estimated13h 16m
Optimistic16h 28m
These are calculated sensitivity cases, not a statistical confidence interval. Conservative uses lower efficiency and battery health, more reserve/temperature loss and higher load; optimistic changes these assumptions in the opposite direction.
- This is an estimate. Real runtime changes with load, temperature, battery age, AC/DC output, and device behavior. Runtime is conditional on successful startup, compatible voltage/connectors and sufficient output. Verify the actual device setup before relying on these hours.
- Within the tracked power limits; compatibility still needs checking
Show your work
Rated Wh is reduced by efficiency, reserve, battery health, and temperature before it is divided by average load.
- Rated battery
- 1040 Wh
- Usable energy
- 796 Wh
- 1040 Wh x 85% x 90% x 100% x 100%
- Running watts
- 60 W
- Average load
- 60 W
- Max surge
- n/a
- Fixed station overhead
- Unknown (not included)
- 60 W / 85% = 70.6 W battery draw; fixed overhead is unknown and excluded
- Estimated runtime
- 13h 16m
- 796 Wh / 60 W = 13h 16m
- Output path
- AC inverter
- Efficiency (%)
- 85
- Reserve kept unused (%)
- 10
- Battery health (%)
- 100
- Cold weather loss (%)
- 0
This link contains the numeric values you entered, but not custom load names.
Source-Backed Next Steps
Smallest matching record (8h)Jackery Explorer 600 Plus
WattRunTime.com
WattRunTime estimate
Estimated runtime
13h 16mThis setup has comfortable headroom for overnight use, assuming the wattage estimate is realistic.Usable energy796 Wh
Average load60 W
Fixed station overheadUnknown (not included)
Running watts60 W
Max surgen/a
Runtime range
Conservative8h 18m
Estimated13h 16m
Optimistic16h 28m
Show your work
Rated Wh is reduced by efficiency, reserve, battery health, and temperature before it is divided by average load.
Usable energy796 Wh1040 Wh x 85% x 90% x 100% x 100%
Fixed station overheadUnknown (not included)60 W / 85% = 70.6 W battery draw; fixed overhead is unknown and excluded
Estimated runtime13h 16m796 Wh / 60 W = 13h 16m
Assumptions
- 1040 Wh nominal battery capacity
- AC inverter output path
- 85% conversion efficiency
- 10% reserve kept unused
- 60 W average load from 1 load
- 100% battery health
- 0% temperature loss
- Fixed station overhead unknown; not included
Warnings
- This is an estimate. Real runtime changes with load, temperature, battery age, AC/DC output, and device behavior. Runtime is conditional on successful startup, compatible voltage/connectors and sufficient output. Verify the actual device setup before relying on these hours.
- Within the tracked power limits; compatibility still needs checking
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Planning notes
- Capacity class: 1,040 Wh. Size the battery for your measured average load and required hours, including reserve.
- Tracked output: 2,000 W. Compare both running demand and startup demand before using any runtime estimate.
- Solar input limit: 400 W. Actual refill depends on panel voltage/current compatibility, sunlight, angle and charging losses.
Known data gaps
- Unverified or missing specifications remain visible. The confidence label describes the station record, not a tested runtime or approval for emergency use.
- Weight: unknown. Check the complete carrying setup, cables and battery extensions before choosing this model for travel.
- unknown: DC output, Weight
Sources
- FIRMAN official ZERO E product page (Official; checked 2026-08-27)