How to Charge a Car Battery

How to Charge a Car Battery

Charging your car battery properly ensures long life and reliable starts. Whether it’s completely dead or just low, the right method makes all the difference.

What You’ll Need

  • Battery charger – Smart chargers are recommended
  • Eye protection – Safety goggles or glasses
  • Gloves – For safety and insulation
  • Well-ventilated area – To prevent gas buildup

Step-by-Step Guide

1. Park & Prepare

  • Turn off your vehicle
  • Set the parking brake
  • Open hood and locate battery
Step 1 Image

2. Check Battery Type

  • Is it a Standard Flooded or AGM?
  • AGM batteries require a charge with an AGM setting. A smart charger that will fully charge and maintain the battery at a full charge is preferred.
AGM vs Standard B AGM vs Standard A

3. Connect Charger

  • Red (positive) clamp to positive terminal (+)
  • Black (negative) clamp to negative terminal (–)
  • Not sure? Check the battery label or consult your owner's manual
Connect Charger

4. Set Charger Settings

  • Select the correct voltage (usually 12V)
  • Set charge rate (slow is best for deeply discharged batteries)
Set Charger Settings

5. Start Charging

  • Plug in charger
  • Monitor progress on charger display (some shut off automatically when full)
Start Charging

6. Disconnect Safely

  • Unplug charger first
  • Remove clamps in reverse order: black (–), then red (+)
Disconnect Safely
Pro Tip Icon Pro Tips
• Never smoke or spark near a charging battery – it may emit flammable gases
• Use a smart charger – It prevents overcharging and adjusts automatically
• Inspect battery – Look for corrosion or leaks before charging

When to Replace Instead of Recharge

  • It’s more than 3–5 years old
  • Doesn’t hold a charge even after full recharge
  • The case is swollen, cracked, or leaking
Replace Battery

Stay Powered Up

Keeping your battery charged extends its life and prevents unexpected breakdowns. If your battery can’t hold a charge, it might be time for a replacement.

Find a New Battery

About Clarios

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And so does the battery
that powers each of them.

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Clarios creates the most advanced battery technologies for virtually every type of vehicle. We are a global leader in energy storage solutions, powering one in three of the world’s vehicles. We partner with our customers to develop smarter solutions that make people’s lives better.