A standard UK car battery lasts 4–6 years. Stop-start (AGM) batteries last 5–7 years. Short-trip drivers (under 15 minutes per journey) often kill batteries in 3 years or less because the alternator never fully recharges them. Cold winters in Scotland and northern England are typically when weak batteries finally die.
Battery life is dominated by use pattern, not mileage. Here are the figures UK garages actually see.
How much does a new car battery cost UK? — Standard £80–£140 fitted, AGM stop-start £150–£280 fitted at an independent.
Can a battery be flat after one cold night? — Yes — if it was already weak. Cold weather reduces battery output by 30%+, so a marginal battery fails on the first frost.
Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email bob@bobsmechanicalrepairs.co.uk.