Straight talk
The case of the weak truck battery
Saturday, August 30, 2008
Wheels: Gary of Dayton writes by e-mail, "My new 2004 Chevrolet truck (new to me) starts just fine and all seems OK. However, a couple of times now when I go to lunch and just turn the engine off and listen to the radio and have a few lights on (not the headlamps), the battery runs down really fast and will not start the truck. My first thought was the battery. So I jumped the battery, went home and put a battery charger on it. The charge showed the battery was 98 percent charged.
What do you think is going on here? By the way, the truck always starts right up in the morning, so there isn't anything electrically going on in the truck that would drain the battery at night. I guess what is happening is the battery is very slowly dying, which is not the way batteries usually do. They usually are fine one day and then without warning, they drop dead.
Halderman: The first thing I thought about was that this could be a result of a poor electrical connection at the battery. The truck is equipped with a side-post design battery, and corrosion can often occur at the positive post. To check, first remove the negative battery cable to guard against the possibility of a connection between the wrench and the body of truck when the positive battery cable is removed. Check for corrosion (acid buildup), and clean and neutralize the acid using a baking-soda-and-water mixture.
If you do not have baking soda, the corrosion can be neutralized by pouring a diet soft drink over the area (a regular soft drink will leave a sugary mess). The carbon dioxide in the carbonated drink will clean off and neutralize the corrosion.
If corroded, this could be a temporary fix as the corrosion is a sign that the battery is gassing during charging, which is a sign of sulfated plates, a type of battery failure caused by age.
Wheels: Will the battery last if all that was wrong was a corroded battery cable?
Halderman: Maybe. Hot weather is hard on batteries and while they do tend to fail when called to start the engine when the temperature is cold, the damage occurred during the hot summer. This is why most batteries today are covered in a foam or plastic covering in an attempt to keep the battery temperature cool when placed under the hood.
Some vehicles have the battery under the rear seat or inside the truck to help keep the battery as cool as possible. Batteries in warm climate areas do not last as long as batteries in cooler locations.
Wheels: What can Gary do if the cable connections are OK?
Halderman: Gary stated that his truck is a 2004 model, which means that it is about 4 years old. Batteries have a normal service life of three years to five years. What would I do? Because Gary just purchased the truck, I would replace the battery and make sure all of the electrical connections are clean and tight.
James D. Halderman is an ASE-certified master technician, a member of the Society of Automotive Engineers and the author of more than a dozen textbooks. His latest is Automotive Technology: Principles, Diagnosis and Service. Submit your automotive care questions to Halderman via e-mail at jhalderman2@juno.com, or write him in care of: Wheels, Marketing Publications Department, Dayton Daily News, 1611 S. Main St., Dayton OH 45409.