dead battery

Is it a dead battery or a bad alternator?

In Battery by Steves Auto Repair and Tire

If you’re having some starting issues or your car seems sluggish or cranking a little slow in the morning, it could be a sign of a dead battery.

Making sure the battery cables aren’t corroded is one quick step you can take. That could not only affect the power coming out of the battery but also the alternator’s ability to charge it.

While the car’s running and as you’re driving, the alternator is there to produce all of the electricity for your accessories and charge up the battery.

If the cells in the battery are going bad, or the battery terminals are corroded, or there’s a wiring issue,  it can impact the battery’s ability to be fully charged. So, when you go out the next morning it might crank but it may feel a tad slow. That’s a really good sign to get your vehicle’s electrical system checked. 

dead battery

Problems with the alternator

When you’re driving down the road, especially as you’re hitting 1,500 rpm to 2,500 rpm, your alternator is going to produce about 14.2 volts. 

It can reach up to 15 or 16 volts, but if it’s getting too high all the time that can cause problems. You also don’t want it too low. 

An alternator may not be bad enough to turn on the battery indicator light on the dashboard, because it’s charging 12.8 or 12.9 volts. It’s enough to keep everything running during the day, but when you have the lights and windshield wipers on at night and you park in your parking spot, it’s really not enough to charge the battery like it should be.

When you’re starting to notice any of these symptoms, bring it to an auto repair shop near you and have a full electrical test performed. A lot of places will only do a voltage test or check the status of the battery at that time. 

The battery could be low on water. But you don’t want to just use tap water. Instead electrolyte water for batteries – or at least distilled water – should be used.

If it’s a sealed battery, well there’s nothing else to really check. You also want to check the charging system and the amperage. A lot of these quick testers that many places use don’t test the amperage. So, you’re almost missing half of the information. A good tester would be able to check the capacitance of the battery, the alternator, and the amperage of the alternator.

It’s important to consider the age of the battery, as well. When you hit 5 to 7 years on a battery – especially if it’s a 5-year-battery – it is time to change it. 

Extremely cold and hot temperatures is one of the factors that can cause a car battery to fail. So, why take a chance when winter time is coming?

Steve’s Auto Repair & Tire is an authorized Goodyear tire dealer located in Woodbridge, Virginia. Automotive repair services are performed on all makes and models, including BMW and Mercedes. Services include oil changes, brakes, alignments, inspections, and computer engine diagnostics.