What a C&I Battery Contract Promises, Clause by Clause

A commercial & industrial (C&I) or utility-scale battery asset is a 15-to-20-year capital decision dressed up as a hardware purchase. The number that decides whether the asset pays for itself is not in the datasheet. It is in the warranty clause — and most of the risk sits in three lines nobody reads before signing.

What the fine print actually controls. Across the industrial storage contracts we review, three clauses do most of the damage to a project’s economics:

1. Throughput cap (energy throughput limit). A battery can carry a 10-year warranty that quietly expires after a fixed number of MWh cycled through it. A site that cycles harder than the vendor assumed hits that cap in year six or seven — and the “10-year” promise ends early. For a facility manager sizing a system against a payback model, this is the single most expensive number to get wrong.
2. SOH degradation, as defined where. A “70% state-of-health” guarantee means nothing until you know under what conditions it is measured — ambient temperature, depth of discharge, calendar vs cycle aging. Two vendors can both promise “70% SOH at year 10” and one of them is promising it at a duty cycle your site will never actually run.
3. Cycles vs calendar years — whichever comes first. “10 years or a fixed cycle count, whichever occurs first” is the standard formulation, and it means the warranty is a race the vendor has already handicapped.

Why this is a contract problem, not an engineering problem. Degradation, throughput and SOH are negotiable terms. They allocate who carries the financial consequence when the asset underperforms — the owner, the EPC, or the financier. That allocation is what a lender reads when it decides whether a project is bankable. A storage project does not get financed on its inverter efficiency; it gets financed on its contracted, enforceable performance obligations.

Regulatory floor — EU 2023/1542. From 18 August 2024, rechargeable industrial batteries above 2 kWh must meet mandatory performance and durability requirements under the EU Battery Regulation; carbon-footprint declarations for industrial batteries became enforceable from 18 February 2026, and the digital battery passport follows on 18 February 2027. (Source: Regulation (EU) 2023/1542 — enforcement timeline, retrieved 2026-09-28.) These set a compliance floor, not a commercial guarantee — which is exactly why the commercial terms above still decide your outcome.

What to do before you sign. Get the exclusions list, the throughput cap, the SOH measurement conditions, and the degradation-allocation clause in writing — and run them through a contract risk review before the PPA or the financing closes. The asset you are buying will outlive the sales conversation by two decades.

Last updated: 2026-09-28.

Updated for commercial and industrial readers, September 2026.