What is a modular battery pack?
A modular battery pack is a battery built from independent, individually replaceable modules rather than a single sealed unit. When a module degrades or fails, it can be swapped, repaired or upgraded without scrapping the whole pack, reducing repair cost, waste and raw material demand.
Replacing a single module instead of a €5,000 to €20,000 pack: that is what modular design makes possible.
How a modular pack works
The pack is organised in modules with standardised mechanical, electrical and thermal interfaces, each monitored by the battery management system. Diagnosis identifies the weak module; service replaces only that module.
Benefits: cost, waste, upgradability
Module-level repair turns a €5,000 to €20,000 pack replacement into a much smaller intervention, keeps vehicles on the road longer, and creates a stream of healthy used modules for second-life applications.
The trend toward cell-to-pack designs improves energy density but reduces repairability: modularity is a deliberate design choice for circularity.
Design principles
Key principles: reversible assembly (bolted, not welded or glued), accessible fasteners, standardised module formats, per-module monitoring data, and safety-by-design for service operations.
Frequently asked questions
- What is a modular battery pack?
- A battery pack composed of independent modules that can be individually diagnosed, replaced or upgraded, instead of a sealed single-unit pack.
- Can you replace a single module in an EV battery?
- Only if the pack was designed for it: modular packs with reversible assembly allow module swaps; sealed cell-to-pack designs generally do not.
- Why are modular battery packs cheaper to repair?
- Because a failed or degraded module can be replaced alone, avoiding the cost of a full pack replacement.
- Do modular packs help the environment?
- Yes: they extend pack lifetime, reduce battery waste and feed healthy modules into reuse, lowering raw material demand.