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title: "Battery degradation: how much to budget over 10 years" description: "Why batteries fade, how to plan a buffer, and what installers can do to extend life." lastUpdated: "27 Feb 2026"

Battery degradation (planning a buffer)

Lithium batteries lose capacity gradually, with both cycles and age. You can plan for that:

• Size with a 10–30% buffer beyond today's need.
• Keep the battery cool. Siting matters.
• Avoid leaving it sitting at 100% or 0% for long periods.
• Use sensible min/max state-of-charge limits and charge-power limits.

If backup matters, hold a reserve, a minimum state of charge, so the battery isn't empty when an outage hits.