What’s wrong with my SUV’s new battery?
John Paul, AAA Northeast's Car Doctor, answers a question from an SUV owner whose two-month-old battery won't keep a charge.
Q. Recently a neighbor of mine helped me jump start our 2005 Chevy Trailblazer. The battery was only two months old. I told him the truck had not been driven in about two weeks. No lights were left on and no doors were open. He commented that this is typical with new batteries, that they don’t hold a charge like the older or original ones, especially if the vehicle is idle for weeks. I found this a little puzzling and wondered if his comments were accurate?A. The original battery in your vehicle has a 690-cold cranking (CCA) rating and an electrical reserve capacity of 90 minutes. As an example, the AAA replacement battery has an 800 CCA rating and a 115-minute reserve. As a general rule, the engine off current rating shouldn’t exceed 25 milliamps. Based on this simple calculation the replacement battery should be able to crank the engine over well past 30 days. At this point the prudent thing to do would be to fully recharge the battery and test the vehicle for parasitic draw (current draining the battery when the engine is off).
John Paul is AAA Northeast’s Car Doctor. He has over 40 years of experience in the automotive business and is an ASE-certified master technician. E-mail your car question to [email protected].
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