The engine and headlights won't start when you get into the car.You should find out if you need a new battery after you start the car.To check a car battery, follow these steps.
Step 1: The ignition needs to be turned off.
Step 2: The battery's positive terminal cover needs to be removed.
Clean the battery terminals.
Step 3: Your battery's positive terminal should be connected to the positive lead of your voltmeter.
The positive lead is usually red.
Step 4: Attach a negative battery terminal.
Step 5: Check the meter.
If your battery is in good condition, you should be able to get between 12.4 and 12.7 volts.The battery needs to be charged if the reading is less than 12.4 volts.The battery is a slow charge if the reading is less than 12.2 volts.And then check again.You have excessive voltage if the reading is over 12.9 volts.The high beams should be turned on to remove the surface charge.The alternator may be overcharging the battery.Load testing is something you may want to do.
Step 6: The battery has a positive terminal cover.
Step 7: The positive terminal on your battery should be connected to the Power Probe's positive lead.
The positive lead is usually red.
Step 8: Attach the Power Probe's negative lead to the negative battery terminal.
Step 9: Attach the tip of the probe to the positive battery terminal.
The probe should be checked for voltage reading.
Step 10: Check the power probe reading.
If your battery is in good condition, you should be able to get between 12.4 and 12.7 volts.
Step 11: "Crank the engine by turning the ignition until the starter engages and hold for 2 seconds."
Step 12: The power probe should be read at the time of the crank.
It shouldn't go below 9.6 volts.The battery is sulfated if it has a reading of less than 9.6 volts.