Core concept
Chemistry is one input; the complete pack and its controls determine real behavior.
Battery life assumptions
Battery Chemistry, Depth of Discharge, and Aging
LFP, NMC, and other chemistry labels identify part of a cell design, not a guaranteed pack lifespan or usable-energy percentage. Real aging depends on chemistry, pack design, battery management, temperature, state of charge, depth and frequency of cycling, current, and calendar time.
Planning impact
Depth of discharge describes how much of the available window a cycle removes.
What to verify
Cycle-life and remaining-capacity claims need model-specific conditions and evidence.
Planning Wh = nominal Wh × battery-health factor × temperature factor × output efficiency × (1 - reserve).
Battery Chemistry, Depth of Discharge, and Aging
LFP, NMC, and other chemistry labels identify part of a cell design, not a guaranteed pack lifespan or usable-energy percentage. Real aging depends on chemistry, pack design, battery management, temperature, state of charge, depth and frequency of cycling, current, and calendar time.
A chemistry label is not a full specification
LFP and NMC describe lithium-ion cathode families, but cells and packs within a family can differ in electrodes, format, thermal design, firmware, voltage window, and protection. Use chemistry for filtering and context, not to invent a universal efficiency, usable capacity, or cycle count.
Depth of discharge is a cycle description
Depth of discharge is the portion removed from the battery's available state-of-charge window during a cycle. It is related to, but not identical to, the calculator's reserve input: reserve is a planning margin, while actual depth of discharge depends on where the cycle starts and stops and on the battery-management limits.
Aging includes cycling and calendar time
Battery lifetime models consider temperature, state-of-charge history, depth and frequency of cycling, current rate, self-heating, and time. Capacity and power capability can change differently. Use the exact manufacturer's health or warranty definition when available and measure delivered energy when the decision is important.
Evidence and review
These sources support the definitions and planning method. Calculator results are still estimates, not measurements or guarantees.
- DOE Explains...BatteriesU.S. Department of Energy · Government reference — Open source
- Predictive Battery Lifetime Modeling at NRELNational Renewable Energy Laboratory · Research report — Open source
Model current health, not marketing life
Use the battery-health input to test a current planning range. It does not predict future cycle life. Keep chemistry, age, temperature, and measured behavior as separate evidence rather than collapsing them into one invented percentage.
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Power station model
Power station modelEcoFlow DELTA 2
Battery capacity (Wh): 1024 WhContinuous output rating (W): 1800 WSurge output rating (W): 2700 W
Estimated runtime13h 3m8h 10m – 16h 13mEstimated runtime: 13h 3m, 8h 10m – 16h 13m
Output path
Estimated runtime
13h 3mEstimated runtime: 13h 3mThis setup has comfortable headroom for overnight use, assuming the wattage estimate is realistic.
Usable energy783 Wh
Average load60 W
Running watts60 W
Max surgen/a
Conservative8h 10m
Estimated13h 3m
Optimistic16h 13m
Conservative assumes harder conditions; optimistic assumes favorable conditions.
Show your work
Rated Wh is reduced by efficiency, reserve, battery health, and temperature before it is divided by average load.
Rated battery1024 WhBattery capacity (Wh): 1024 Wh
Usable energy783 Wh1024 Wh x 85% x 90% x 100% x 100%
Average load60 W60 W running, 60 W average after duty cycle and quantity
Estimated runtime13h 3m783 Wh / 60 W = 13h 3m
- 1024 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
- This is an estimate. Real runtime changes with load, temperature, battery age, AC/DC output, and device behavior.
This link contains the numeric values you entered, but not custom load names.
Source-Backed Next Steps
Smallest matching record (8h)Jackery Explorer 600 v2WattRunTime.com
WattRunTime estimate
Estimated runtime
13h 3mThis setup has comfortable headroom for overnight use, assuming the wattage estimate is realistic.Usable energy783 Wh
Average load60 W
Running watts60 W
Max surgen/a
Runtime range
Conservative8h 10m
Estimated13h 3m
Optimistic16h 13m
Show your work
Rated Wh is reduced by efficiency, reserve, battery health, and temperature before it is divided by average load.
Rated battery1024 WhBattery capacity (Wh): 1024 Wh
Usable energy783 Wh1024 Wh x 85% x 90% x 100% x 100%
Average load60 W60 W running, 60 W average after duty cycle and quantity
Estimated runtime13h 3m783 Wh / 60 W = 13h 3m
Assumptions
- 1024 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
Warnings
- This is an estimate. Real runtime changes with load, temperature, battery age, AC/DC output, and device behavior.
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Margin guide
Reserve and Battery Health
A runtime plan is safer when it leaves margin for age, cold, changing load, and measurement error.
Capacity guide
Usable Capacity vs Rated Capacity
A 1,000 Wh label is the starting point, not a promise that 1,000 Wh reaches your device.
Cold-weather planning
Cold Weather Battery Runtime Guide
Cold can reduce available energy and power, while battery heaters and connected loads may consume additional energy. Plan with margin and follow the exact model's temperature limits.
Chemistry, depth of discharge, and aging FAQ
Understand how chemistry, depth of discharge, temperature, state of charge, and use history affect battery planning without universal cycle-life claims.
Does LFP always last longer than NMC?
Do not make that decision from the chemistry label alone. Compare model-specific warranty terms, stated test conditions, pack controls, operating limits, and independent measurements. This site does not assign a universal cycle-life number to a chemistry family.
Is a 10% reserve the same as 90% depth of discharge?
Only in a simplified full-to-reserve planning case. Real depth of discharge depends on the starting and ending state of charge plus the pack's usable window, so reserve should not be presented as a measured cycle depth.