Symptoms drivers describe
- Slow, laboured cranking or no crank at all
- Flat again a day or two after a jump start
- Central locking and electrics behaving oddly
- Battery warning light on while driving
- Worse in cold weather
Possible causes
- A battery at the end of its service life
- A charging fault, for example a failing alternator
- A parasitic drain from a module, aftermarket fitment or faulty switch
- Mainly short journeys never fully recharging the battery
- Corroded terminals or poor earth connections
- The wrong battery type or specification fitted previously
What you can do
- Note how long the car stands before it goes flat
- Mention any accessories fitted, such as dash cams or trackers
- Ask for the charging system and drain to be tested before buying a battery
How we check it in the workshop
We load-test the battery, measure charging voltage and current at the alternator, then measure quiescent current draw to find a drain rather than simply selling a replacement.
Is it safe to keep driving?
Not dangerous, but it will strand you eventually — and a new battery on a car with a drain goes flat too.