Battery test?

My garage has recommended that I replace the 5 year old battery in my car and avoid failure in cold weather. The mechanic mentioned that it failed a test twice. At the moment, the car starts admirably and after topping up with my trickle charger, a cold start is just as good as a warm start.

What battery test is conducted to determine potential failure in cold weather?

Reply to
accent
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What is the battery's rated life? Most are 60 to 72 months and they last about that long. As for testing, read here, about half way down the page

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I do know that having a battery fail when it is 4 degrees and windy sucks. Why did you have to top up the battery with the charger? How cold is cold? The cranking power drops rapidly along with the temperature. Should you buy a new battery as we are heading into winter? That depends on your tolerance for pain and inconvenience. If you are starting to have problems, yes, definitely. If your garage is just trying to sell batteries, get another test someplace else.

Reply to
Edwin Pawlowski

If you trust your mechanic, then you better take his advice. That's because a 5 year old battery is quite old. Only a few last 5 years, and fewer still last to 6. Believe me, it will let you down at the worst possible moment.

The cheap batteries last ~4 years, the expensive ones last ~5 years, but cost nearly twice as much. So it's your call on how much to spend.

A standard load test will usually reveal the problem.

If you don't have a load tester, a simple voltage test will give you a rough idea: When you come home, do a simple voltage test with the engine turned off. You should get ~13.5v give or take. Check the voltage the next morning, preferably after a chilly night. If your voltage didn't change much, it's a good sign. If the voltage drops ~1v or more, it's a bad sign. Keep in mind this is a rough test, but it can be a useful indicator. -

Bob

Reply to
Bob Adkins
13.5V is charging voltage. I've never once seen voltage this high on a car that was off.
Reply to
hyundaitech

Mine usually stays between 12.85 and 13.50v. Charging voltage is usually around 14-14.5v. I guess each vehicle will vary by .5v or so.

The real test is not the absolute battery voltage, but the difference between warm and cold battery voltage. -

Bob

Reply to
Bob Adkins

13.8-14.7 is typical charging voltage. Optimal target voltage for charging has to be calculated against the battery's temperature. I'm not sure about the Hyundai but my Dodge has a sensor on the bottom of the battery tray for this reason.

JS

Reply to
JS

If you are seeing above 12.8V from a lead-acid battery that has set for any length of time at all after charging, then you need to have your voltmeter calibrated. :-)

Matt

Reply to
Matt Whiting

True! The self-discharge curve is very steep for the first hour or 2 after a full charge. You can actually stand there and watch the voltage drop pretty quickly in .01v increments. -

Bob

Reply to
Bob Adkins

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