3 July 2026 · 4 min read
How long does a home battery last?
By Stefan Douw · Maker of Stekkerkompas
Count on 10 to 15 years. That is the honest range for a home battery, and the number says less than most sellers suggest. A battery does not wear out by the year but by the number of times you fill it and drain it. How you use it decides where in that range you land.
Cycles cause the wear, not the calendar
Almost every home battery sold today is LFP (lithium iron phosphate). That cell type reaches roughly 6,000 full charge cycles before usable capacity drops to 80 percent. Convert that to time: at one cycle a day, that is over sixteen years on paper. The older NMC cells sit well below that at 3,000 to 4,000 cycles, which is why LFP has become the standard for home use. Each charge and discharge also costs energy: round-trip efficiency is around 90 percent, so about 10 percent of what you put in does not come back out.
What the warranty actually covers
Most manufacturers give a 10-year warranty with a minimum capacity retention of 70 percent, some brands 80 percent. Watch the catch: the warranty runs until the number of years or the number of cycles is reached, whichever comes first. BYD and Tesla, for example, cover 6,000 cycles or 10 years. Burn through those cycles faster and the warranty ends sooner, even if the ten years are not up. So always ask for both figures, not just the years.
Trading earns money but speeds up the wear
Use the battery only for your own solar power and you make about 250 to 300 cycles a year. Let it actively trade on the imbalance or day-ahead market and that rises to 1.5 to 2 cycles a day, meaning 500 or more a year. Then that stock of 6,000 cycles is gone not in sixteen years but in six or seven. The trading income is real, but it comes with a wear cost. Factor the shorter lifespan in when you work out what trading earns you.
Temperature and a full battery do the rest
A battery ages even while it sits idle, which is called calendar aging. Two things speed it up: heat and staying fully charged for long stretches. The ideal environment is 15 to 25 degrees. A battery sitting above 30 degrees all summer degrades noticeably faster than one in a cool utility room or garage. So a cool, dry spot genuinely matters for where you place it.
Run your own numbers
The calculator uses an economic life of 15 years, about 6,000 cycles, and shows the return as a band rather than a neat round figure. Run your own numbers in the calculator.
Sources
Run the numbers for your home
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