The Economics of Module-Level Testing

Testing needs cyclers, fixtures, climate control, trained technicians and, above all, time. A full capacity test charges and discharges each module at a controlled rate, which can take many hours per module before rest periods and data review are added. Once handling, dismantling, data processing and equipment maintenance are included, testing becomes a meaningful cost that has to be justified by the value it unlocks.

Pack format has a major influence on that cost. Large bolted prismatic modules are straightforward to connect and test, whereas structural or adhesively bonded packs may need substantial dismantling before any module can be reached safely. In some cases that dismantling effort outweighs the cost of testing itself, which changes the calculation about whether detailed grading is worthwhile for a particular model.

The payoff is the ability to separate reusable modules from those that belong in refining. Second-life modules usually command more per kilowatt-hour than the value of their contained metals, particularly for LFP chemistry, where black mass value is modest. Without testing, every module is effectively priced as if it were going straight to refining, and the difference between those two outcomes is money left on the table.

Testing also reduces risk for buyers of second-life modules, who will pay more for material backed by credible, serial-level data. For sellers, test results provide evidence to support pricing and reduce the likelihood of disputes later. The combination of higher achievable prices, faster sales and fewer disagreements is what usually justifies the bench time invested in grading. In most consignments the uplift comfortably exceeds the cost of testing.

Screening tests such as open-circuit voltage checks, DC resistance pulses and impedance measurements can quickly identify modules that clearly fail, so full capacity tests are reserved for promising candidates. Automated fixtures and parallel cycling channels raise throughput considerably, and analysis software can flag anomalies for a technician to review instead of relying on manual inspection of every data file. Technicians then spend their time on judgement rather than on routine checks.

Vehicle data helps too. Battery management system history, where it is available, can indicate which packs are worth testing in detail and which are likely to go straight to refining. The goal is not simply to test less, but to spend expensive bench time where it genuinely changes the routing decision and therefore the value returned to the owner. Every hour saved on obvious cases can be spent where it matters.