Depth of discharge (DoD) is the share of a battery's capacity you empty in one cycle. A 90% DoD cycle on a 5 kWh pack uses about 4.5 kWh and leaves about 0.5 kWh in reserve. A 100% DoD cycle would empty the pack completely.
What it means for a home battery
DoD links usable capacity to warranty claims. Manufacturers often quote cycle life at a stated DoD and temperature. EcoFlow's STREAM cycle-life note on the STREAM AC 5000 UK page says testing is at 25±2°C, 0.25P charge/discharge rate, 90% depth of discharge, with at least 60% capacity retention at end of life. The warranty policy sets the contractual detail.
For day-to-day tariff shifting you usually want to use as much usable energy as the schedule allows, because each kWh moved from the night rate to the day rate is where the saving comes from. Habo's best-case maths for a 5 kWh EcoFlow STREAM assume a full daily cycle of delivered energy, then apply a 90% round-trip efficiency assumption. That is separate from EcoFlow's 90% DoD test condition: one is an efficiency assumption Habo states because EcoFlow does not publish round-trip efficiency, the other is EcoFlow's cycle-life test setting.
When you compare warranties, read the DoD next to the cycle count. The same cycle count at 90% DoD is not the same as that count at 70% DoD. EcoFlow's STREAM cycle-life note on the product page quotes testing at 90% DoD (with the temperature and rate above); treat any other brand's cycle figure as that brand's claim under its own test conditions. See home battery cycle life and warranties, what size battery, and the glossary.
In practice, the app schedule and the battery management system enforce the usable window. You rarely set DoD as a raw percentage yourself. What you should check on the quote is the usable kWh and the DoD used in the cycle-life or warranty table so two brands are compared on the same basis.
Keep an eye on UK battery prices
Leave your email for occasional updates on UK home battery prices, tariff changes and the 0% VAT deadline. No spam, unsubscribe any time.
Thanks, you're on the list.
Frequently asked questions
It means the test or schedule uses 90% of the pack's capacity in a cycle and leaves about 10% in reserve. EcoFlow's STREAM cycle-life test is specified at 90% DoD.
Using more of the pack shifts more kWh per day, which can raise the saving, but warranty cycle counts are often quoted at a stated DoD. Compare like with like.
Habo's cycle life and warranty guide covers how manufacturers quote cycles, capacity retention and years.
Simple battery, simple install
Electrician-wired EcoFlow STREAM from £2,499. Habo will try to serve anyone who registers in an area where we have an electrician. Nothing to pay today.
Join the waitlist