Common Problem

Why Your Battery Won't Stay Charged

If charging or jump-starting a battery only buys you a few hours before it's flat again, that's not a fluke — it's a specific signal about the battery's internal condition that a top-up charge won't fix.

What's actually happening inside the battery

Batteries store charge through a chemical reaction between lead plates and acid electrolyte. As a battery ages, sulfation builds up on the plates, reducing their ability to hold charge — the battery can still accept a charge temporarily, but loses it far faster than it should because its actual storage capacity has degraded.

Ruling out other causes first

Before assuming the battery itself is the problem, it's worth checking for a parasitic drain — something drawing power even when the car is off. If the battery genuinely won't hold charge even with nothing else connected or drawing power, that points strongly to the battery itself rather than an external drain.

When replacement is the right call

A battery that repeatedly won't hold charge, especially if it's more than 2-3 years old, is very unlikely to recover — this is a sign of genuine internal degradation rather than something a charge or jump start will permanently fix.

Need to get going right now?

If the battery's flat at this exact moment, a mobile jump start will get the car started so you're not stuck waiting — see our guide on a dead battery for what to do immediately, then book the replacement once you're back.

Frequently Asked Questions