Depth of discharge tells you how much of the pack you have spent—not just the voltage on the display. This battery depth of discharge calculator converts used and total watt-hours into DoD % for cycle planning and chemistry limits.
Benefits
- Core formula: DoD % = (used Wh ÷ total Wh) × 100.
- DoD % = 100 − state of charge (SoC %) on the same Wh basis.
- Compare daily cycles to manufacturer max DoD recommendations.
How it works
- Enter energy used in Wh (meter, coulomb count, or load × time).
- Add total pack capacity in Wh (from Ah × V or nameplate kWh × 1,000).
- Read depth of discharge %—check against chemistry and warranty caps.
FAQ
How does the battery depth of discharge calculator work?
DoD % = (used Wh ÷ total Wh) × 100. Example: 600 Wh drawn from a 1,200 Wh pack → 50% DoD. That matches 50% remaining SoC when both numbers use the same gross capacity baseline.
Is DoD the same as 100% minus SoC?
Yes on the same energy reference: 70% DoD means 30% SoC remains. Use consistent total Wh—nameplate at full charge—not an aged capacity estimate unless you intentionally derate total Wh first.
What DoD is safe for my battery?
Typical planning limits: flooded lead-acid ~50% daily; AGM 50–60%; LiFePO4 often 80–90% with BMS reserve below that. The calculator reports actual DoD; compare the result to your datasheet max cycle DoD.
Technical specifications
- DoD % = (energy_used_Wh ÷ total_capacity_Wh) × 100.
- SoC % ≈ 100 − DoD % (same Wh basis).
- Used Wh must not exceed total Wh.
- Related: battery-depth-of-discharge, battery-percentage, battery-dod-energy-yield.
DoD measures how much tank you emptied
Voltage gauges drift with load and temperature; energy accounting in watt-hours is steadier. A battery depth of discharge calculator turns used Wh and pack Wh into a percentage cycle depth. Operators tracking nightly off-grid use can log DoD daily and spot when average depth exceeds warranty-friendly limits.
Chemistry sets the acceptable DoD ceiling
Lead-acid cycle life collapses when daily DoD routinely exceeds 50%. LiFePO4 marketing allows deeper swings, but BMS may still hold reserve below 10% displayed SoC. Calculate DoD from measured Wh, then compare to the line in the spec sheet—not to generic 100% depth assumptions.
From DoD to usable energy planning
After a cycle's DoD is known, gross pack Wh × (DoD ÷ 100) confirms energy delivered. Pair with Battery Energy for total Wh, Battery DoD to Energy Yield when sizing from nominal kWh and target DoD %, and Battery Percentage when starting from voltage-reported SoC instead of Wh used.