Ask most people what causes a breakdown and they'll say something mechanical: a blown engine, a snapped belt, worn brakes. The reality is far less dramatic. Across almost every type of vehicle and equipment we deal with at McMartins, from cars and vans to generators, mobility scooters and golf carts, the single biggest cause of failure is the same: the battery.
The car data
RAC data shows battery issues are the number one reason for patrol call-outs all year round, with the problem getting worse in winter. AA figures back this up: January and February are consistently the busiest months for roadside call-outs, with the AA responding to over 270,000 breakdowns in January and around 255,000 in February in a typical year, and flat batteries are the most common cause.
A Kwik Fit survey of over 2,000 drivers found battery failure was the biggest cause of their most recent breakdown (17%). What's interesting is the mismatch between what drivers worry about and what actually goes wrong. Brakes were the number one concern (15%), yet brakes only caused 3% of breakdowns. Batteries barely registered as a worry (4%) despite being the leading actual cause. Most people simply aren't thinking about their battery until it lets them down.
Separate analysis of over 550,000 vehicles found around 1 in 4 UK cars is running on a weak 12-volt battery, which works out to roughly 8.6 million vehicles on the road right now with a battery that's already on its way out. It's the same principle for vans and commercial vehicles: more electrical load, more idle time between shifts, more strain on a battery nobody checks until it fails.
It's the same story everywhere else
This isn't just a car problem. Once you look across other equipment types, the pattern repeats almost exactly.
Standby generators. Battery failure is widely reported as the leading cause of generators failing to start, particularly during power outages when they're needed most. In some estimates, battery issues account for roughly half of all generator start-up failures. For anyone relying on backup power, fire alarm systems, or emergency lighting, this is the failure point that gets overlooked because everyone's focused on fuel and the engine, not the small industrial or standby battery that has to crank it all into life.
Mobility scooters. The battery is consistently named as the leading cause of breakdowns, usually down to poor charging habits, age, or the battery being left to fully discharge. For scooter users, this isn't an inconvenience, it's a loss of independence at the worst possible moment.
Golf carts. Same again. Battery-related issues are the leading cause of performance problems and no-start situations, most commonly from sulfation, old age, or corroded connections.
Boats. Slightly different picture here. Battery and electrical issues are a genuine and recurring cause of breakdowns, especially engines that won't start at the quayside after a period sat idle, but they compete closely with fuel-related problems (contamination, empty tanks, clogged filters) for the top spot rather than clearly leading the field. A properly maintained leisure or marine battery still removes one of the most common causes from the list.
Why batteries fail more than anything else
A few things make batteries the weak point across almost every type of equipment:
- They degrade quietly. Unlike a worn tyre or a squealing brake, a battery losing capacity gives very little warning until it simply doesn't have enough left to start the engine.
- Cold makes it worse. At 0°C a battery can lose around 20% of its capacity. At -18°C that can rise to 50%, at exactly the time an engine needs more power to turn over.
- Short or infrequent use doesn't help. Short journeys, seasonal equipment, or anything left standing for weeks (a second car, a generator, a boat over winter) doesn't give the battery a proper chance to recharge.
- Age catches people out. Most batteries have a working life of 3-5 years, but a lot of equipment gets used well past that point simply because nothing has visibly gone wrong yet.
The takeaway
The equipment changes but the cause doesn't. Whatever you're running, whether it's a fleet vehicle, a backup generator for a fire and security system, a boat, or a golf cart, the battery is more likely to let you down than anything else on board. Testing and replacing on a schedule rather than waiting for a failure is the cheapest insurance available.
At McMartins we stock batteries across car, commercial vehicle, industrial, and leisure and marine applications, plus chargers to help extend the life of the battery you've already got. Not sure what you need? Use our battery finder tool to get matched to the right fit, or get in touch and we'll help you choose.
