Insights ·
8,000 cycles or 6,000: cell-level or system-level?
Same battery, same manufacturer, two thousand cycles of difference between one document and another. Both numbers are true, but only one describes what you buy.
This week, a manufacturer wrote in their commercial table: “8,000 cycles.”
Their technical documents from a month ago said: 6,000.
Same battery. Same manufacturer. Two thousand cycles of difference, 33% more lifespan appearing out of nowhere between one document and another.
We asked. The answer came within 24 hours, honest:
CELL-level.
Cell and system: two different numbers
There's the trap, and almost nobody knows it:
- Cell cycles are measured in a lab, under ideal conditions: perfect temperature, gentle current, the naked cell pampered. The tier-1 cell inside that battery genuinely endures 8,000 that way.
- System cycles are measured on the complete battery: BMS, electronics, real heat, real loads. There, the certified number was 6,000.
Both numbers are true. But only one describes what you're buying.
Why the difference isn't academic
A bank finances against the system's certified life. A warranty is enforced on the system. And your savings are produced by the system: a bare cell won't power a lightbulb.
Whoever has the report sends it within 24 hours. It happened to us this week, and that manufacturer earned points.
Whoever doesn't, changes the subject.
We don't buy pretty numbers. We buy reports.