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Dead car battery: jump-start it or call a tow?

ZeroTow · Updated October 9, 2026

In South Florida heat, batteries die more often than people expect. Here's how to tell if it's the battery, how to jump-start safely, and when a tow is the better call.

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Is it really the battery?

  • Clicking noise or nothing at all when you turn the key, and the dashboard lights are dim or off: that usually points to the battery.
  • The engine cranks slowly or struggles: often a weak battery.
  • The engine cranks normally but won't catch: more likely fuel or ignition, not the battery.
  • The car died while you were driving, or the battery light came on first: the alternator may be the problem, and a jump-start won't fix it.

How to jump-start it safely

  • Park the working car close, but not touching, and turn both cars off. Read the owner's manual first, because some cars have a special jump point under the hood.
  • Connect red to the dead battery's positive (+), then red to the good battery's positive (+).
  • Connect black to the good battery's negative (−), then the other black clamp to bare metal on the dead car, away from the battery. Not to the dead battery's negative post.
  • Start the working car, let it run a few minutes, then try the dead car.
  • Remove the cables in the reverse order. Keep the engine running and drive for a while so the battery recharges.

When not to jump it

  • The battery is swollen, cracked, leaking or smells like rotten eggs.
  • There's corrosion or damage you can't safely clean.
  • It's an electric car, or a hybrid with a warning in the manual. Many have their own rules for a dead 12-volt battery.
  • You're on a busy road or highway shoulder. Safety first: stay in the car, hazard lights on, and call for help.

When to call a tow

Call for a tow if the jump doesn't work, the car dies again right after, you suspect the alternator, or you can't jump it safely where you are. Open the ZeroTow app, put the pin on the car, choose where it's going (home, or a shop that can test the battery and alternator) and see the full price before you confirm. In the note for the driver, say it's a dead battery, plus any garage height limit or gate code.

Keep it from happening again

Heat shortens battery life. If the battery is a few years old, have it tested. Many auto parts stores and shops test batteries for free. Replace it before it strands you.