What does Depth of Discharge (DoD) mean?

Explanation

Depth of discharge measures how deeply you drain your battery before plugging in again. If you charge to 80% and drive until you hit 20%, your depth of discharge is 60%. If you charge to 100% and drive to 0%, your DoD is 100%.

DoD matters for battery longevity. Shallower discharge cycles (smaller DoD) generally result in more total cycles before the battery degrades significantly. A battery that is regularly cycled between 30% and 70% (40% DoD) will last longer in terms of total energy throughput than one cycled between 0% and 100% (100% DoD) each time.

For daily driving, this means plugging in frequently and keeping the battery in a comfortable middle range is better for long-term health than draining to near-empty before recharging. This is a general guideline, though. Modern battery management systems handle edge cases well, and occasional deep discharges are not harmful. The goal is to avoid making 0-100% cycles a daily habit.

Based on data from National Renewable Energy Laboratory.

Where you'll see this

• In vehicle specifications

Common confusion

People sometimes think they should never let their battery go below 20%. While staying in the 20-80% range is ideal for NMC batteries, occasional dips below 20% are perfectly fine. It is the daily habit that matters, not occasional exceptions.

Example

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