How To Charge A Car Battery

How to Charge a Car Battery
Here’s a helpful step-by-step guide on how to charge a car battery. By: RICH CEPPOS AND COLLIN MORGAN
UPDATED: NOV 7, 2023

What to Expect:
Estimated time: 5 minutes for setup, 1–6 hours for battery charging, overnight for a full recharge
Experience level: Beginner
If you can’t find the battery terminals under the hood, checking the owner’s manual will save a lot of time.
What You’ll Need
Along with a battery charger, there are a few things you might need when tackling this job—these will do the trick.

Battery Charger
Magnetic Light
Extension Cord (if needed)
Pocket Screwdriver for battery cover removal (if needed)

How to Recharge Your Car Battery: Step-By-Step
Step 1: Find your vehicle’s battery and locate the positive and negative terminals.
Most cars have their battery under the hood. The positive terminal is marked with a “+,” and the negative terminal is marked with a “-.” Sometimes the terminals are protected by plastic covers that need to be flipped out of the way. Other vehicles have their batteries in the trunk. If you’re struggling to find them, consult that handy owner’s manual

Step 2: Verify your battery charger is unplugged and turned off.
Before attaching the battery charger, it’s important to verify no current is flowing through it before connecting to the terminals on your vehicle. Unplugging it prevents sparks—which can be dangerous if your battery is leaking. Read the instructions that come with the battery charger, as each charger operates a little differently.

Step 3: Attach the battery charger to your vehicle’s battery terminals.
Attach the charger’s red clamp to the battery’s positive terminal and the black clamp to the negative terminal. Give the clamps a little wiggle to ensure that they have a good connection to the terminals. For the greatest safety, keep the charger as far away from the battery as the cables allow.

Step 4: Plug the charger in and turn it on.
Some chargers can identify the battery automatically, while others need to be inputted manually. Once that’s figured out, simply select which charging amperage you want. As a rule of thumb, higher amperage = faster charge times, while lower amperage is slower, but more gentle on your vehicle’s battery, possibly extending its life.

Other chargers work differently; they may not shut off automatically but rather have gauges that let you know when the battery is charged. Many battery chargers deliver two to six amps and can take at least several hours to recharge a dead car battery. Double-check the instructions that come with the charger to be sure you’re operating it correctly.

Step 5: Disconnect everything once the battery is charged.
When the battery is fully charged, shut off the charger and unplug it. Then remove the cables, unhooking the negative (black) clamp first.