Many drivability and starting problems may be due to low battery voltage (C5 and early C6’s have column locks common problems associated to battery voltage). It’s a simple thing to check, and overlooked as a possible source of trouble. Low battery voltage can also affect fuel delivery by causing the fuel pump to run slower than normal. This, in turn, causes, low fuel pressure and a lean fuel condition. Under some conditions, a low battery may even prevent one or more injectors from opening normally causing lean misfire and/or hard starting.
Automotive lead-acid batteries must be kept at or near full charge for optimum performance and longevity in today’s cars with serious computer controlled electronics. If a battery is run down or becomes fully discharged, undesirable changes start to occur on the lead plates inside the battery. The plates develop a layer of sulfate that resist recharging and reduce the battery’s ability to store power. If the battery is chronically rundown or discharged, it shortens battery life significantly.
Average battery life under the optimum conditions is only about four or five years in most vehicles, and only about three years in places where summer temperatures typically soar into the triple digits. Many people who are driving cars with batteries that are four, five or six years old may not realize their batteries are failing until their car fails to start and leaves them stranded.
The best way to check battery charge is with a digital voltmeter. A fully charged battery should read 12.65 volts. A reading of 12.45 volts equals about a 75% charge and is good enough for further testing. Anything less means the battery is low and needs to be recharged.
The battery’s state of charge doesn’t tell the whole story because a fully charged battery may also be a weak or failing battery that can’t provide its normal amp output under load. Battery condition can be determined one of two ways: by load testing with a tester that applies a calibrated load on the battery (this requires the battery to be fully charged for accurate test results), or by testing with an electronic “conductance” tester (which does not require a fully charged battery for accurate test results).
Conductance testers send a frequency signal through the battery to reveal how much active plate area is available to hold and deliver power. As a battery ages, its conductance declines. Shorts or open conditions and other cell defects also affect conductance, so measuring conductance gives an accurate indication of battery condition.
Many electronic battery testers also analyze the battery’s “Cold Cranking Amp” (CCA) capacity, which can be used to estimate the battery’s remaining service life. Some testers also measure the amps drawn by the starter while cranking the engine, and analyze the charging system’s output under load once the engine is running.
If a car needs a new battery, it should have the same or higher CCA rating as the original equipment battery specified by the vehicle manufacturer. Batteries should be fully charged before they are installed. Other items that should always be inspected and may need to be replaced include battery cables, anti-corrosion washers for the battery terminals, battery tray and/or battery hold-down hardware and clamps.
Battery Safety is Important?
Every year, nearly 6,000 people suffer serious eye injuries or even blindness because of improperly jump-starting a dead battery. All vehicle batteries contain sulfuric acid and produce hydrogen and oxygen gases. If the hydrogen gas comes into contact with a spark, the battery can explode, sending pieces of the battery and acid flying in your direction before you can react.
What should you do if battery acid comes in contact with an eye? You should flush the affected eye with the first drinkable liquid available, such as water, milk, juice or a soft drink. The longer you wait, the greater the chances of a serious eye injury. Flush the eye for at least 15 minutes before seeking emergency medical attention.
Tips for safely jump-starting a vehicle
1. You should own a pair of jumper cables tested and approved by the Society of Automotive Engineers (SAE). Jumper cables that are not in good condition are dangerous to the person jump-starting the car. Purchase cables that are at least 12-feet long and color coded.
2. In addition to jumper cables, you should carry: splash-proof, safety goggles for eye protection; a flashlight; and a step-by-step guide for jump-starting a vehicle.
3. When jump-starting, remember: -
- Turn off everything that produces an electrical load; lights, heater etc.
- Set parking brakes.
- Make sure batteries are the same voltage.
- Cover the vent caps of both batteries with a damp cloth.
- Attempt to jump-start a frozen battery.
- Never allow the two vehicles to touch each other.
- Never allow the jumper cables to touch each other.
- Never lean over the battery when making connections.
5. Preventative maintenance is the best defense against vehicle failure. Check car batteries for cracks or corrosion before seasons change.
6. USE COMMON SENSE WHEN WORKING WITH YOUR BATTERY.
By: James Prunty