Coventry: from car plants to batteries

It's half past four on a Friday at a supplier's site near Coventry. The cell that welds busbars onto battery modules has thrown a fault. The robot is fine. The vision system can't find its datum, and the line behind it is filling up with modules.

Your shift engineer has twenty years on presses and transfer lines. They can strip a gearbox blindfold. They've never worked near a high voltage battery pack and they say so. Fair play to them.

So who do you call? That question is new for a lot of Coventry sites, and the answer is getting harder to find.

Same city, different kit

Coventry still makes things. In 2024 manufacturing accounted for 14,000* employee jobs in the city, 8.6%* of the total. Across Great Britain the figure was 7.3%* (Nomis, ONS labour market profile).

The region's link to cars runs deep. An ONS study found the West Midlands held 32.6% of Great Britain's motor vehicle manufacturing jobs in 2018, up from 29.0% in 2008 (ONS). We set out the wider picture in manufacturing in the West Midlands.

What's changing is what those jobs work on. The UK Battery Industrialisation Centre opened in Coventry in July 2021. The government describes it as the national facility that "provides the missing link" between battery technology that works in the lab and mass production (GOV.UK). Batteries now sit next to automotive and aerospace among the priority sub-sectors in the government's advanced manufacturing plan (Skills England).

So a supplier that used to machine engine parts may now be building trays, cooling plates or busbars. A test house that ran engine dynos may now be charging and cycling packs. The machines on the floor look different, and so do the faults.

What a battery line asks of an engineer

On a traditional line, most breakdowns are mechanical, pneumatic or a sensor. On a battery line you get all of those, plus:

• high voltage DC on the product itself, not only on the machine
• laser and ultrasonic welding cells
• vision systems doing the positioning
• tight humidity and cleanliness controls in some areas
• charge and discharge rigs with a lot of stored energy
• robots doing most of the handling

HSE's guidance on electric and hybrid vehicles gives a sense of the voltages. It says vehicle systems run at up to 650 volts* DC. It also warns that in dry conditions, contact with parts live above 110 volts* DC can be fatal (HSE, electric and hybrid vehicles).

The same page makes a point every fitter should hear. Even when isolated, batteries and other parts "may still contain large amounts of energy and retain a high voltage". You must test and prove dead before working on any high voltage cable or part. Your usual lock-off routine still applies, but on its own it falls short. We cover the basics in safe isolation: lock off, tag out, prove dead.

Know the kit before you touch it

The law here is short. Under regulation 16 of the Electricity at Work Regulations, nobody should do work where technical knowledge or experience is needed to prevent danger unless they have it, or are suitably supervised (regulation 16).

HSE's vehicle guidance splits work into four categories. Working on high voltage systems is the top one, and people doing repair and maintenance "are likely to need a much greater level of competence" than people doing sales or valeting (HSE). Your factory won't match those categories exactly. The principle carries over: the closer someone works to the high voltage, the more training and experience they need.

That's why the engineer in the opening scene did the right thing. A good mechanical fitter who says "not on this one" is protecting you. Sending them in anyway is how sites end up in front of HSE. Our piece on the Electricity at Work Regulations for maintenance managers covers the wider duties.

The cost of the wrong engineer

Here's our view. On new kit, the most expensive mistake is sending the wrong person and losing four hours before anyone admits it. Having nobody at least makes you pick up the phone.

On a battery line those hours cost more than usual. Modules part-way through a process may need scrapping. Some steps can't simply be paused and resumed. Your customer is often an OEM with tight delivery slots and penalties written into the contract.

So when you ring for help, be specific. Say whether the fault is in the controls, the vision system, the robot or the high voltage side. Say what tickets you need. A controls engineer who knows the PLC and the robot may get you running without going near the pack. A high voltage fault needs someone trained for it, every time. Our guide to fitters, electricians and controls engineers helps you work out which is which.

There's a staffing point too. The people who can work on this kit are in demand all over the region. Skills England reports that 29%* of advanced manufacturing's priority jobs are in critical demand (Skills England). If you only start looking when the cell stops, you'll be at the back of the queue.

What to do on Monday

1. Walk your line and mark every point where an engineer could meet high voltage on the product or the test rigs.
2. For each one, write down who on your team is trained to work there. If the answer is nobody on nights, that's your gap.
3. Check your isolation procedure includes stored energy and proving dead on the high voltage side.
4. Line up an outside engineer with the right high voltage training before the next fault, and get them inducted on your site.

* Employee job counts and shares (ONS Business Register and Employment Survey 2024, via Nomis), the HSE voltage figures and the 29% demand figure correct as of 30 September 2026. Check the Coventry labour market profile, HSE's electric and hybrid vehicles page and the Skills England sector assessment for the latest.