2002ls1z Posted February 14, 2009 Report Share Posted February 14, 2009 Had on oil change and they also tested my battery for me also. They recommended that I replace my battery b/c it tested at 77%. That doesn't sound bad to me. Input? Quote Link to comment Share on other sites More sharing options...
slick Posted February 14, 2009 Report Share Posted February 14, 2009 How old is the battery? Quote Link to comment Share on other sites More sharing options...
2002ls1z Posted February 14, 2009 Author Report Share Posted February 14, 2009 Dunno. Bought it used. Quote Link to comment Share on other sites More sharing options...
slick Posted February 15, 2009 Report Share Posted February 15, 2009 Can you see if there is a date stamp on the battery? Quote Link to comment Share on other sites More sharing options...
1990lumina Posted February 15, 2009 Report Share Posted February 15, 2009 Depends if you live in a cold climate or not. If you live in a warm climate I'd run the battery till you canhear the car turning over slower in the morning, etc... If you live in a cold climate (like me where it's -40º for a considerable amount of days in a row) I reccomend you replace it. Get something with the biggest CCAs as possiblethat will fit. Remember batteries only have HALF of their rated CCA capacity @ -18º. A battery with 600CCA will only have 300CCA on a colder day (or even less), and your motor requires MORE amps to get things moving as well. Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted February 15, 2009 Report Share Posted February 15, 2009 Remember batteries only have HALF of their rated CCA capacity @ -18º. A battery with 600CCA will only have 300CCA on a colder day (or even less), and your motor requires MORE amps to get things moving as well. Is this true? I believe you since you've had auto tech training, but I've never heard that before. It really doesn't get that cold down here, so maybe that's why I've never heard that. To the OP: I agree if you live in a cold climate I would check the date stamp and probably replace it. With that said I've never seen a battery tester with percentages. Usually its a pass/fail thing. Quote Link to comment Share on other sites More sharing options...
1990lumina Posted February 15, 2009 Report Share Posted February 15, 2009 Remember batteries only have HALF of their rated CCA capacity @ -18º. A battery with 600CCA will only have 300CCA on a colder day (or even less), and your motor requires MORE amps to get things moving as well. Is this true? I believe you since you've had auto tech training, but I've never heard that before. It really doesn't get that cold down here, so maybe that's why I've never heard that. To the OP: I agree if you live in a cold climate I would check the date stamp and probably replace it. With that said I've never seen a battery tester with percentages. Usually its a pass/fail thing. Depends on how it is rated. Some manufactures write the rating AT -18º and some don't. Quote Link to comment Share on other sites More sharing options...
AL Posted February 15, 2009 Report Share Posted February 15, 2009 I am in an auto tech program right now at school... We have a battery tester that will put a load on the battery and see if it maintains the proper voltage (9.6v) which is either pass or fail... We also have a little handheld machine that can check the batterys life, which comes out as a percentage... Quote Link to comment Share on other sites More sharing options...
1990lumina Posted February 15, 2009 Report Share Posted February 15, 2009 At work I use a Snap-On MicroVAT. It's works great. Tests the whole charging and starting system - or just individual tests. It'll say either pass or fail, but if you go in further it'll give you the specifics. The wireless printer for it doesn't work anymore though Quote Link to comment Share on other sites More sharing options...
Schurkey Posted February 21, 2009 Report Share Posted February 21, 2009 Batteries can be rated several different ways. The trick is figuring out how those various ratings compare to each other. Cold Cranking Amps (CCA) (the de-facto standard for the automotive industry) is rated at 0 degrees F. Cranking Amps (CA) (what the cheapass junk battery companies use because it results in bigger, more impressive numbers) is rated at 32 degrees F, as is Marine Cranking Amps which makes sense as not many people are using their boat when the water is colder than 32 degrees F. There are other systems for battery ratings--reserve capacity, for instance--that have gone out-of-favor and aren't advertised much anymore. In the old days, you had to FULLY CHARGE a battery; test it's temperature; and read the rating info on it's label. Then you actually loaded the battery based on 1/2 of it's CCA rating for 15 seconds. If you had more than a certain amount of residual voltage at the end of that 15 second test (and the exact amount of voltage depended on the battery temperature!!!) then the battery passed the test and should be fit for continued use. If the battery couldn't maintain the specified voltage for 15 seconds of load testing, the battery was either not fully charged to begin with; or it was defective. It took time and skill and attention to detail to properly test a battery. Today, there's thousand-dollar hand held devices that electronically test the battery by playing Van Halen into the + and - terminals. The hand-held tester somehow "knows" how much load capacity the battery has; and you get an LCD screen or tape-register printout showing the test results. Which is probalby what was done to get your "77%" reading. Very fast, as you don't need to charge the battery or test it's temperature; and a minimum of skill needed. What hasn't been verified is: WAS THE TESTER PROPERLY PROGRAMMED WITH THE TRUE CCA OF YOUR BATTERY? If they told the tester that you had a bigger battery than you actually have--of course it's coming up short in the test results. So--short story: IF (big IF) those test results are correct--a battery at 77% is probably stressing your alternator; and NOT providing full current to the starter. I would want such a battery O-U-T of my vehicle. BUT! Do you trust the people who worked on your car? Quote Link to comment Share on other sites More sharing options...
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