Dead Car Battery vs Bad Alternator: How to Tell the Difference
Your car won't start — battery or alternator? Before buying a new battery, read this. A Brampton tow truck driver explains the symptoms of each.
Dead Battery vs Bad Alternator — How to Tell
When your car won't start or dies while driving, it's almost always one of two culprits: the battery or the alternator. Getting the diagnosis wrong means buying a new battery when you actually need an alternator (or vice versa).
Signs of a Dead Battery
The test: Jump-start the car. If it starts and runs fine for hours/days, it's likely the battery.
Signs of a Bad Alternator
The test: After a jump-start, drive for 10 minutes. If the car dies again, it's almost certainly the alternator.
The Chicken-and-Egg Problem
A failing alternator will destroy an otherwise healthy battery over weeks. A heavily discharged battery can make a perfectly good alternator seem like it's failing. If your car has had multiple battery issues in the past 12 months, always have the alternator tested before replacing the battery again.
When to Call for a Battery Boost vs a Tow
Need a battery boost in Brampton, Mississauga, or the GTA? We're 15–20 minutes away. Call 647-673-9755.
Need a Tow in Brampton or the GTA?
24/7 dispatch. 15–20 min ETA. Licensed & insured.