Updated · Batteries
The engine turns over slowly
The most common early sign is a starter that sounds tired: a slower, dragging crank before the engine catches. It's often worse on the first start of the morning or after the car has sat in the sun.
If you hear it two or three days in a row, the battery is losing capacity. Get it tested before it stops starting the car altogether.
Clicking, dim lights and electrical oddities
Many cars with start-stop turn that feature off when the battery gets weak, so a change in how it behaves is an early clue. Watch for these too:
- Rapid clicking when you turn the key or press the start button
- Headlights or dash lights that dim at idle or while the engine cranks
- Power windows that move slower than usual
- A radio or clock that resets on its own
- Start-stop that no longer shuts the engine off at red lights
Signs you can see or smell
Pop the hood and look. White, green or blue crust on the terminals can block current even when the battery is still good. A swollen or bulging case usually means heat damage, and a rotten-egg smell means the battery may be overheating or leaking.
A swollen, cracked or leaking battery should not be jumped. Keep sparks and flames away from it and have it replaced.
Battery or alternator?
A battery warning light that comes on while you drive usually points to the charging system, not just the battery. If the car starts after a jump but dies again on the road, or the lights fade as you drive, the alternator may not be charging. That repair is a job for a repair shop.
With a simple voltmeter, a healthy battery at rest reads about 12.6 volts. With the engine running, you should see roughly 13.5 to 14.5 volts. A running reading near 12 volts suggests the alternator isn't doing its job.
What to do when you notice the signs
Don't wait for the car to stop starting. Skip short trips that drain the battery without giving it time to recharge, and get it tested soon.
If it has already left you stuck, we can jump-start the car or replace the battery where it sits. If the real problem is the alternator, a new battery alone won't fix it, and the technician will tell you that before any work.