Keep the spark alive: RAC warns against the ‘flat battery blues’ on ‘back to reality day’

Head of Policy

5 minute read|31st Dec 2025

Many will already be dreading ‘back to reality day’ – Monday 5^th January – when they have to head back to work after the festive period, which is why the RAC is warning drivers to make sure it’s not made even worse by a bad case of the ‘flat battery blues’.

The first day of a new working week after New Year is notorious as the worst day of the whole year for vehicle breakdowns due to thousands of cars having been left idle over the holiday period, leading to older, weaker batteries slowly draining to zero and failing. It’s expected to be especially problematic this year given the recent cold weather which will test the chemical reaction of car batteries to the limit.

On the first Monday of 2025 a quarter (24%) of all RAC breakdowns were due to flat batteries. Battery issues have long been the number one cause of RAC breakdowns with patrols attending hundreds of thousands every year.

RAC mobile servicing and repairs team leader Nick Mullender said: “A flat battery at the start of the new year is more than enough to drain away the last of the Christmas spirit. If you’re one of the millions of drivers taking to the roads on Monday, make sure you’ve given your car a really good run in the days beforehand, even if it’s just to fill up with fuel.

“This advice is particularly relevant for families with two or more vehicles who only use one over the festive period, or anyone returning from a holiday abroad where their car has been left parked up. The combination of a long break where vehicles aren’t used and the recent cold weather is a perfect recipe for the ‘flat battery blues.’

“There’s no exception either when it comes to the type of car you drive. Electric vehicles face the same risk as internal combustion engines because they also depend on 12-volt batteries for starting. To avoid problems, motorists should take them for occasional drives and keep the high-voltage battery charged above 20% during winter.”

The RAC recommends these top tips to avoid a ‘flat start’ to the new year:

Park under cover where possible – a garage offers the best protection against cold weather
Switch everything off at the end of your journey – lights, heater, fan, heated rear windscreen, and radio should all be turned off. Unplug dashcams and other devices which can drain the battery overnight
Inspect battery connections – ensure terminals are tight and free from corrosion. Remember, battery acid is highly corrosive to skin and paintwork. The RAC website carries a full guide
Test your battery if it’s over four years old – older batteries are far more likely to fail in cold conditions
Take your car for a proper drive before you need it – a decent run charges the battery and warms the engine. Simply starting the car briefly can drain the battery further. And, if it doesn’t start, you have more time to sort it out.

If your battery is in need of replacing, you can book in with an RAC Mobile Mechanic to fit a new battery on your driveway.