MG’s Halol Plant: How women build batteries powering one of India’s bestselling EVs

JSW MG Motor India has built a strong presence in India’s electric vehicle market. The company was among the early movers when it introduced the ZS EV back in 2020. Fast forward to 2025, MG now proudly holds the title of having one of India’s best-selling EV: the Windsor.

With battery packs forming the backbone of any electric vehicle, the company has invested heavily in ensuring this critical component is built with precision and scale.We recently visited MG’s advanced battery manufacturing facility in Halol, Gujarat, where packs for both the Windsor Pro and the Comet EV are assembled. This assembly line is capable of producing up to 140 units a day. Interestingly, the shop floor is unique not just for its technology but also for its workforce.

The first thing that stands out isn’t the machines, but the people. MG has put real emphasis on building diversity within its production teams, and nowhere is this more evident than on the battery shop floor. At one stage, the entire line was run exclusively by women, and even today, they make up close to 80 percent of the workforce. More importantly, their presence isn’t limited to routine assembly tasks. Many are leading teams, handling quality checks, and taking up supervisory and managerial responsibilities.

MG Comet, Windsor Pro: Battery specs

The Comet battery uses 150Ah cells arranged in 5 modules, with a rated voltage of 116V and total capacity of 17.3 kWh. It comes with an air-cooling system for thermal management. Its dimensions are 1129 × 932 × 240 mm. On the other hand, the Windsor battery is more powerful, using 171Ah cells with a much higher rated voltage of 310V. This gives it a capacity of 52.9 kWh. It also features a liquid cooling system for better heat control.

Inside the Battery Shop

The Windsor’s larger 52.9 kWh pack is a good example of the level of detail involved. Each pack contains 98 individual cells, and before assembly begins, every single one undergoes an open-circuit voltage test to ensure it meets standards. The process then moves to lower box preparation, where insulation pads are carefully laid out before the cells are slotted in.

From there, the modules go through an insulation withstand test, followed by bus-bar assembly and laser welding, which fuses the connections with precision.

A voltage-sensing harness is added, again using laser welding for accuracy, and then comes module layer testing. To improve durability, a foam pasting process is used to stabilize the pack before final assembly.

Even after this, the job isn’t done. Each completed battery undergoes charging and discharging cycles on the final line to ensure real-world reliability. Any cell or module that fails at any stage is removed from the line.

MG says this zero-compromise approach is what helps its EVs earn customer confidence.

The result

For buyers, the result of this process is a battery pack that not only delivers range and performance but also inspires trust: an area where many EV owners still have concerns. The Windsor, with its certified range of up to 449 km on the 52.9 kWh pack, is proof of how these batteries translate into strong market acceptance.And the numbers speak volumes. Since its debut in September 2024, the Windsor has crossed 30,000 units in wholesale sales, accounting for nearly 60 percent of MG’s passenger vehicle sales in India.

Just last month, the company dispatched 4,511 units, making it the country’s consistent EV bestseller.By controlling battery manufacturing in-house, MG is not only aiming to ensure quality but this will also facilitate quicker adaptation to demand, stronger supply chain control, and a tighter grip on costs: something critical as battery prices continue to make up the biggest share of an EV’s sticker price.