How are car batteries made? We visit JSW MG Motor in Gujarat to find out

The JSW MG Motor plant in Halol, Gujarat, is massive. Originally a General Motors facility, it has been completely retooled for the joint venture. Spanning over 170 acres and backed by an initial investment of Rs 2,000 crore, the factory has the capacity to produce more than one lakh vehicles annually, with room to expand if demand grows. Inside this campus sits the battery assembly shop – the one we were going to check out. Every MG Comet and Windsor draws its power from the packs built here, with around 140 packs assembled daily. Our visit was to understand this process closely, from the first cell being placed to the final pack being slotted into a car.

Entering the facility, you realise it’s a bit different from what you were expecting. I expected big robots handling everything, but surprisingly, it’s mostly done by hand. Another striking aspect of the shop is the workforce. More than 80 per cent of the operators here are women. They are not only doing assembly but also handling managerial roles. The company has built hostels for them, runs buses to ferry them in, and even hosts family days and festivals inside the factory grounds so that the work isn’t isolated from the rest of their lives. Across JSW MG’s workforce, women now make up 41 per cent. On this floor, they are the majority.

The work itself is precise and a bit physical. But the brand keeps the workers’ safety in check. Workers never carry more than the safe limit by hand – anything heavier is shifted mechanically. Shin guards and ESD gloves are also part of standard safety gear.

The battery making process starts with a foam layer being placed in the lower box to insulate the cells. Then, the cooling tray is inserted, and the cells are stacked. Afterwards, brackets are placed to secure the cells in position. This is followed by the first test – each cell is tested for open-circuit voltage and polarity. This is also where every single cell is logged and linked to the pack number. This way, if there is a problem later in the vehicle’s life, the error can be traced back to the exact unit.

After this, bus bars are welded to connect the cells. This is where the laser welding robot comes in, because the work requires absolute precision. Once the bus bars are in place, workers fix the voltage-sensing wire harnesses that connect to the Battery Management System, which is essentially the brain of the battery. The pack then receives its charging sockets, high-voltage jumper system, and all necessary connectors. These parts are what will eventually interface with the car – allowing current to flow in and out safely. Each connection is checked and logged.

From this point onwards, the pack is treated as a high-voltage unit, and we were told to maintain more distance than usual. More than 30 parameters are measured at the final test, from battery capacity to insulation resistance. The pack then goes through a charge-discharge cycle. It is charged to 100 per cent, discharged to 0, and then charged to 55-60 per cent before packaging.

Final packaging involves adding sealants, gaskets, the upper foam layer, and the top housing. The battery pack is then weighed. If the weight does not match the specification, the pack is flagged. Only those that pass every step move forward to the vehicle assembly line.

That line looks very different. Bare shells come in from the paint shop on conveyors. As they reach their stations, workers add parts step by step. At the battery station, robots bring in the finished pack and lift it carefully into the underbelly of the chassis. Human operators tighten every connection and supervise the placement. Once that’s done, the body then proceeds to other stations for various parts like the doors and wheels.

Walking out of the factory, you leave with a sense of admiration. Admiration for the people who spend hours on the line, repeating each step with unwavering focus so that every pack is identical. Admiration, too, for the safety protocols – from shin guards to leak tests – that safeguard both worker and customer.

Credit goes to the brand as well. It is not just turning out 140 battery packs a day; it is doing so with women as the majority of its workforce, with processes designed to leave nothing to chance. India’s future, electric or otherwise, depends on efforts like these, carried out shift after shift with discipline and care. And even though EVs are known for their effortless experience, I now understand that behind it all is hard work, vigilance, and care.