Battery Depth of Discharge Calculator

Enter your battery's rated capacity and recommended max DoD to see usable capacity and estimated cycle life impact.

⏱ ~10 sec🔋 Lithium & lead-acid🔒 No signup

Result

180 usable
Usable capacity at recommended DoD
Recommended max DoD90%
Typical cycle life at this DoD~3,000-6,000 cycles

Discharging deeper than recommended shortens cycle life disproportionately — staying within the chemistry's recommended DoD is the single biggest factor in battery longevity.

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Why depth of discharge determines both capacity and lifespan

Usable capacity = Rated capacity × Max DoD %

Depth of discharge is how much of a battery's total capacity you actually use before recharging — LiFePO4 batteries tolerate deep, near-full discharge with minimal lifespan penalty, while lead-acid batteries degrade rapidly if regularly discharged past 50%. This is why a 200Ah lithium battery often delivers as much practical daily capacity as a 300-400Ah lead-acid bank — check the resulting usable Ah against your battery sizing calculator results.

Frequently asked questions

Why do lead-acid batteries need such a shallow discharge?

Lead-acid chemistry suffers accelerated plate degradation when regularly discharged deeply, so limiting to 50% (or even 20-30% for longest life) is standard practice to get a reasonable cycle life.

Does discharging a lithium battery to 100% DoD damage it?

Occasional full discharge is generally fine for quality LiFePO4 cells, but many manufacturers still recommend 80-90% as a routine max to maximize total cycle life over the battery's lifetime.

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