The battery is 30–40% of an electric truck’s value, and the battery warranty is the only instrument protecting it. Yet “8-year warranty” can describe anything from a robust performance guarantee to a marketing sentence. Four clauses decide which you are holding.

1. The SoH floor. A real warranty promises a state-of-health floor — the battery will retain at least X% of original capacity by Y years or Z kilometres, measured by a defined method. SANY’s e263 documentation (8 years / 1.2 million km, SoH ≥ 70%) is currently the segment’s clearest written benchmark. European incumbents typically negotiate battery terms per contract — potentially excellent, but invisible until quoted, which is why our scorecard penalises opacity rather than terms. No written floor = no warranty, whatever the brochure says.

2. Throughput and usage conditions. Most warranties limit total energy throughput (MWh cycled) or specify charging regimes — caps on fast-charging frequency, temperature conditions, or required maintenance logging. A warranty voided by the megawatt charging your corridor requires is a trap, not a benefit. Ask for the throughput limit in MWh and translate it into your kilometres before signing.

3. Remedy and measurement. When capacity drops below the floor, what happens — repair, module replacement, full pack swap, pro-rated compensation? Who measures SoH, with whose diagnostic tool, at whose cost, and how long does the truck stand? A remedy that takes eight weeks of downtime costs more than the degradation it fixes. Get the claim process in writing, including response times.

4. Transferability. The used-truck market does not exist yet; when it forms, a battery warranty that transfers to the second owner will be the single biggest determinant of residual value. Manufacturer buy-back programmes, where offered, are effectively residual insurance — price them against your residual assumption, not against zero.

WattTonne’s read. Battery warranty terms are now a competitive battleground — Chinese entrants use written guarantees to buy trust, incumbents use per-contract flexibility. Whichever you negotiate: floor, throughput, remedy, transferability — in writing, or it doesn’t count. Our Evidence Files record exactly these four fields per vehicle.