Depth of Discharge Calculator

From inputs to result

For this worksheet, the governing relationship is DoD = removed capacity ÷ rated capacity × 100. Its variables correspond to Capacity removed and Rated capacity.

The defaults produce 60.00%. Replace them with measurements from one operating state.

Calculate depth of discharge from capacity removed and rated capacity. Peukert Battery Runtime Calculator may be useful for the next related quantity.

Preparing the calculation

Use voltage and capacity values from the same battery condition. A source note beside each entry makes the result reproducible.

At least one field has a positive lower bound because it appears in a denominator. A prefix error can move the result by several orders of magnitude.

Capacity removed

Default example: 60 Ah. Enter capacity removed in Ah.

Rated capacity

Default example: 100 Ah. Enter rated capacity in Ah.

What the number means

Interpret Depth of discharge on the same basis used for the source values. Compare it with a warm, cold, new, and aged battery case where relevant.

Keep the input set beside the output so another reader can reproduce it.

Sensitivity check

Change Capacity removed from 60 Ah to 72 Ah with every other entry unchanged. The result changes from 60.00% to 72.00%.

Keep both cases when the changed input represents genuine uncertainty.

Assumptions and limitations

Capacity ratings depend on test rate and temperature.

Outside the entered variables, consider voltage sag, thermal rise, charge taper, and balancing. Resolve material omissions before selecting a standard size or rating.

Separate nameplate capacity from measured usable capacity.

Using this result in a larger analysis

Check the source of capacity removed before calculating. A credible result requires every field to describe the same physical condition and unit basis.

After calculating depth of discharge, compare its magnitude with manufacturer discharge data at the intended rate. An independent order-of-magnitude check can reveal a misplaced decimal or unit prefix.

If uncertainty remains, calculate labeled low and high cases. Include voltage sag, thermal rise, charge taper, and balancing when those effects can change the decision.

Before relying on the answer