How 1 real module is actually joined together
A real electric car battery module holds itself together with more than one method at once, and that mix decides how hard it is to take apart later. A paper in the Journal of Remanufacturing describes a Samsung 12S1P module, used in the Audi Q5 and the Volkswagen E Golf. Screws hold its circuit board cover on, and those come off easily. Busbars, the metal strips that carry current between cells, are welded to the cell terminals. The outer case has a welded seam. The cells themselves are bonded together with adhesive so they cannot shift while the car is moving. The screws are the easy part. The welds and the adhesive resist coming apart cleanly, because both are built to never separate again. Four other module families ship in the Nissan Leaf, the BMW i3 and the Peugeot E 208.
Researchers scored 5 ways to join a pack
A separate team of researchers scored 5 ways to join a battery pack together, weighing 21 criteria including joint strength, cost, recyclability and how easily a joint comes apart. Plain nut and bolt assembly scored highest of all 5, at 82.2%, ahead of laser welding, micro TIG welding, resistance spot welding and ultrasonic wedge bonding. The researchers credit bolted assembly as the only method of the 5 built to be undone on purpose, easy to dismount, easy to repair, and a cold process that avoids heating the cells. Its downside, in the same scoring, is extra weight and cost against a welded joint. This is a scoring framework built by 1 research team, not a count of what packs on the road today are built with.
The score is a scoring framework built by 1 research team across 21 weighted criteria, not a count of what most packs on the road actually use.
Show the numbers
| Ultrasonic wedge bonding | 74.3 |
| Micro TIG welding | 74.1 |
| Resistance spot welding | 71.8 |
| Laser welding | 76.3 |
| Nut and bolt assembly | 82.2 |
How long it actually takes to take one apart
A second team bought a real module and timed how long it takes to strip down. An experienced technician needed 601 seconds, about 10 minutes, to disassemble the module by hand, in 1 timed trial. The same team built a robotic disassembly cell and tested it on the same job. Running slowed to a quarter of its normal speed for safety during testing, the robot took 895 seconds. The researchers project that at full speed the same robot would take 223.75 seconds, under 4 minutes, though it still needs more development before working unsupervised.
The technician figure is 1 timed trial on 1 real module. The robot was deliberately run at a quarter of its normal speed for safety during testing. The full speed figure is a projection the researchers state themselves, dividing the test time by 4.
Show the numbers
| Technician, by hand | 601 |
| Robot, test speed | 895 |
| Robot, full speed | 223.75 |
Why the glue is the hard part
A review of electric vehicle battery housings sums up why glue is the hard part. Strong adhesive blocks material recovery, because removing it either damages the parts underneath or needs a chemical bath that swells the adhesive to break its bond, adding a costly extra step. The review wants modules built as separable units from the start, and names design for disassembly, material traceability and modularity as the 3 strategies the industry should adopt. It does not name any manufacturer as already doing this well.
What the law actually requires, and does not
From 18 February 2027, the European Union will require the maker of every electric vehicle battery to hand over instructions for how the pack comes apart, to anyone with a legitimate interest in recycling, repairing or regulating it, under the EU battery passport rules. That information stays closed to the public, and the requirement is a paperwork duty, not a design mandate. Only 1 of the 5 sources behind this article tracks the design trend over time, and it found that packs are becoming harder to take apart as manufacturers favour performance over future disassembly.