BESS second life

BESS second life covers stationary systems built from repurposed EV modules, and stationary modules reused in a new stationary application, after assessment for the new duty. A repurposed EV battery that is placed on the market as a new battery needs a new passport linked to the original, with the assessment, safety checks, and new application recorded. The assessment must cover state of health, damage, thermal behaviour, and battery management system suitability for stationary duty, which differs from vehicle duty in cycle pattern, temperature, and power demand. The record must name the origin battery, the new application, the assessor, and the operator responsible for the new life. A stationary system built from modules without origin records has no traceable history, and the new operator cannot judge the modules on measured facts.

BESS second life means the use of EV modules, or used stationary modules, in a stationary application after a first life, following preparation for repurposing or reuse. The scope is the modules and the new application stated.

How is the stationary category decided?

BESS second life applies within that frame, and the record should not borrow an EV battery rule without checking whether the article applies to industrial batteries. Articles 3 and 73 is the operative provision for the point in question. An integrator building stationary storage from assessed EV modules should record the category decision, including the capacity calculation and the date, because the threshold decision decides whether a passport is required. A rack built from EV modules should carry the origin identifiers, the assessment results for each module, the new battery management system configuration, and a new passport linked to each origin passport, with the link recorded.

How is the record built in layers?

For BESS second life, each layer should name its source, its date, and its owner. Origin records, assessment reports, and the new system record should be tied to the identifier, so a maintenance entry, a commissioning test, and a passport entry refer to the same system. Mixing modules of different chemistries, ages, or state of health in one system raises balancing and safety questions, and the record should state the mixing rule applied and the checks that support it, rather than present mixed modules as a uniform system.

How is performance measured in service?

For BESS second life, the record should state the capacity test method, the temperature range, the charge and discharge rates, the depth of discharge, and the end of life criterion used for a durability statement. An integrator building stationary storage from assessed EV modules should name the standard or method used for each value and should not present a laboratory value as a site value without stating the difference. A rack built from EV modules should carry the origin identifiers, the assessment results for each module, the new battery management system configuration, and a new passport linked to each origin passport, with the link recorded.

How is safety information recorded?

For BESS second life, the record should state the safety tests applied, the battery management system functions that protect the system, the ventilation or enclosure requirements, and the instructions given to the site operator. Origin records, assessment reports, and the new system record should include the test reports, the installation instructions, and the handover of safety information, each dated. Mixing modules of different chemistries, ages, or state of health in one system raises balancing and safety questions, and the record should state the mixing rule applied and the checks that support it, rather than present mixed modules as a uniform system.

How are installation and maintenance recorded?

For BESS second life, the commissioning record should state the installer, the date, the tests passed, the settings applied, and any deviations from the design. An integrator building stationary storage from assessed EV modules should ensure that maintenance entries update the passport or the linked record where the Regulation requires an update, and that earlier entries are preserved. A rack built from EV modules should carry the origin identifiers, the assessment results for each module, the new battery management system configuration, and a new passport linked to each origin passport, with the link recorded.

How are transfer and end of life decisions recorded?

For BESS second life, a transfer of ownership, a change of application, a repurposing of EV modules into stationary service, or a move to recycling each needs a dated entry, a named operator, and a statement of what was transferred. Origin records, assessment reports, and the new system record should include the state of health assessment, the safety checks applied, and the new application, where a second life use is claimed. Mixing modules of different chemistries, ages, or state of health in one system raises balancing and safety questions, and the record should state the mixing rule applied and the checks that support it, rather than present mixed modules as a uniform system. An integrator building stationary storage from assessed EV modules should check the passport or linked record at transfer, record any gap found, and give the gap an owner and a review date.

How is a mixed module rack assessed?

Assessing a mixed rack starts with an inventory: each module identifier, its origin, its chemistry, its age, and its state of health, in one table. The modules are then grouped by chemistry and state of health, and the balancing and protection design is checked against the worst group, not the average. A worked assessment for a rack of mixed modules shows the inventory, the grouping, the balancing test, and the acceptance decision with a power limit. Modules that fall below the acceptance criteria are removed and recorded as rejected, with the reason. A rack accepted on an average state of health, where one module is far below the rest, misstates the rack, because the weakest module limits the rack and carries the highest risk.

Second life in stationary service is a new system built from old modules, and the new system record must carry the old history with it, not start from a blank page.