I took my '09 base Fit (< 40K miles) to the stealership for an oil change last week. When the work was finished, I was handed a sheet that showed various findings and made recommendations for maintenance work. One of the findings was that the battery "needs replacing." (The choices were green-Good, yellow-Marginal, red-Needs Replacing. Mine was red.) I'm not sure how they determined this, but assumed it was based on an actual test of the battery, as opposed to just going by the battery date of manufacture or time since installation. This is a Honda 151R, the second I've had in the car. (Actually, it's the third because the second one died long before the warranty was up. So this one is the warranty replacement for the second one.)

I took the car to a Sam's Club yesterday, where they did a free battery check while I watched. The results

Midtronics Out of Vehicle Test
"Good Battery"

Rated: 340 CCA
Measured: 309 CCA
Voltage: 12.84V
Temperature: 89 F
Cranking Health: Good Battery
Reserve Health: OK

How do you interpret these test results? What kind of predictive value does the test have? Specifically, will the test show that a battery is going bad several weeks or months before it dies? Or is it the kind of test that could show the battery is "Good" today but then it turns out that the battery is dead next week?

(I don't really trust the dealership because, for example, when I arrived at the shop for the oil change and asked the guy how much it would cost, he quoted me the highest charge--for synthetic oil--without mentioning that another option was standard oil at 50% lower cost. Had I not already called ahead and asked about the cost including all fees & taxes several days before, I wouldn't have known that I might be about to pay for service I didn't necessarily need.)

 

If the service writer writing up your work order gets commission I am sure he/she always quotes the higher of the 2. Bad business practice if you ask me. Either they were told to do that or took it upon themselves.You should give people options and your opinion and let them make a decision. Is there another dealer you can go to?

They probably didn't test the battery and may have just went by the date. Since your test results show a good battery then I wouldn't worry to much about it. Generally a battery will start to show signs of wear and when it gets close to the 5 year mark I consider just throwing a new one in. It all depends how you use it. If you sit with the car off and music blasting often the battery will go bad sooner. Some cars seem to go through batteries easily but I found my Fit to not be one of them.

 

Honestly, I don't know how to interpret any kind of results for a battery test... but what I can tell you is, shortly before my last battery change, the guys that work at advanced auto/autozone kept getting results saying the battery was GOOD. The dealership I had seen around the same time for other reasons also didn't indicate on the multi-point inspection that I needed a new battery.

And yet, I was having all kinds of electrical issues that was due to a bad battery. It got progressively worse, until the car straight up died and I needed to use my plug in jumper to start the car. Needless to say, I went to an advanced auto and replaced the battery. They still got a "good" battery on the check before doing the replacement anyway (who would they be to deny making money off me). The shop and myself had nothing but questions as to why the car behaved they way it did. All I knew was, the problems went away with a new battery.

And if you're wondering if it was user error, I also checked that too... I couldn't find anything obvious like lights being on. Nor is the plug-in accessory port powered with the key removed, so even if I left something plugged in, it couldn't drain the battery. I don't sit in my car for long periods of time with the engine off and electrical devices going, nor could there be anyone else, since no one else uses my car. As for anything not obvious... I didn't dig too deeply, as it could be a number of things I don't know about.

So, is it possible the test shows a battery is "GOOD" and dies the next week? Well, I'm sure it is, since I had a battery still say it was "good" AFTER it died.

As for the "5-year" life... well, I'm on my third battery with a 2010 Fit. So, for me, its more like 3 years.

 

If you're ever curious you could go yourself to NAPA or Autozone, etc... and ask to have your battery tested and see how it reads on the meter yourself. They'll usually do it for free.

 

You can call the dealership and ask them how they tested the battery.

Those Midtronics results look fine to me although the temperature seems a bit mis-calibrated. In my experience, the battery test results of different stores vary wildly.

I agree with EvanPhi; you should go to a different store for a second battery test to confirm.

 

My background = years managing a NAPA Auto Parts and a strong respect for the Midtronics testers. Also a guy who hates being stranded and would not want his wife in his car and stranded somewhere.

It says good, but the fact that the cranking amps are down, especially while warm, makes me think the battery is showing signs of age. How old was the battery? If a battery makes it to 5 years, I see no reason to wait for it to fail. I start planing to replace it the next time the funds and the time to replace it arises. A battery's voltage is between 12.65 and maybe 13.1 when it is fully charged. It only takes a drop to 11.89v to be considered 0% charged. But honestly, as a guy who has seen a lot of batteries, I see your issue more based on being down on cranking amps. NAPA (Deka) and Interstate, both great brands, will often test well over their rating. The low reserve health is telling us that the battery is not in the best of health to support loads for very long without the engine running. There is no way for me to tell you the exact time, but I can tell you what RC or reserve capacity means on a new battery. RC is the number of minutes your battery can deliver 25 amps before it reaches 10.5 volts. The math can be pretty easy in terms of cutting the 25 in half, will double the minutes.

Hope this helps a little.

 

Up north, when it gets cold, you can get a sense if the battery is weak when you do that initial early morning startup. I have one of those jumper boxes to get bailed out if the battery is nearly dead. If I have to use the jumper, then it's time to get a new battery.

As someone else mentioned, if it's the wife's car, I just change the battery every 5 yrs. I don't need 'that' call, if she's in another state, etc.

 

A battery is approximately $100-$150. Not a major purchase. Not knowing what you do for a living, can you afford to be late for work if your car doesn't start? Are you comfortable with a spouse or teenager stranded if the car doesn't start? You do know the battery can fail anytime during a 24 hour day? It's not necessarily going to fail during the hours of operation of some chain auto parts store. Cars and/or just about every mechanical machine require maintenance. The battery backup in emergency exit lighting need replacement when old, otherwise they might not work when needed. Why would you think your car battery will last forever?

 

I don't think the OP expects it to last forever, more like trying to reconcile the fact the dealership suggested replacing the battery when a store showed a result of "good" and what said results mean.

 

No, the original poster is looking for people to tell him that the battery is good and doesn't need replacement because he doesn't want to spend the money. Doesn't matter why he doesn't want to spend the money, all that matters is they're looking for affirmation that their choice is the correct one. It's a cheap item. Most people would replace it for the security or peace of mind and call it a day.

 

This is the kind of thing I am afraid of.

Good to know!

- Why does the temperature seem mis-calibrated?
- Actually, I did take it to two different places (although both from the same chain). I went to the one I mentioned in the OP after I had already taken it to a different Sam's Club, where I had the wheels rotated for free. I had asked at that other Sam's Club that they also test the battery. When the tech returned the car to me, he didn't mention anything about the battery, so I asked him if it had actually been checked, he said that it had and that it was fine. But when I got home and read over all the paperwork, it stated something to the effect of 'customer declined free battery test,' so I wasn't sure whether he neglected to correct that in the system before printing it out or had just lied to me about having checked the battery.

Makes sense, but I'm in South Florida.

Precisely.

 

I'm retired and it's not easy making ends meet. $100 isn't "cheap" for me. If I had money to spare, I wouldn't be driving a 10-year-old Fit.

I misplaced the paperwork from when I had the current battery installed, but it's approximately 4-5 years old, which is why I've been concerned about the accuracy and utility of battery testing reports.

I appreciate the advice.

 

Thanks. Very helpful info.
Just one question: Roughly speaking, what would be the lowest level of cranking amps for a battery rated like this that would suggest to you that the battery is still in very good health?

 

Your name says Georgia and it was not 89F there that day. In South Florida it might have been for all I know.
I think that is enough testing. Since you have a lot of CCA per first test, have noted no issues, prefer not to spend the $100, and live in a relatively warm area, I might continue driving and check the battery every so often. Due to age, at first signs of issues or poor test results consider replacing.

 

That is a really good question and I'll be absolutely honest... I should back peddle just a little and say that you are not down much. I am so use to seeing batteries that are 600+ cranking amps that when I see one at 309, it just seems low. The reality is that yours is still 90% of new. My initial reaction to your question was, "wow, I really do not know, but I bet 10% is a pretty accurate to how I normally feel," and in this case, 10% is down is right where you are. You have me very interested in doing some Google research. Those who know me, know that I don't always like to just go from feel and I like to find some supporting data. I will say that if I were you and I happened to hear any slow cranking, it would be out with the old right away.

 

It doesn't matter if you're retired and nearly broke or rich and shitting Franklins... if you have to pay for something, you just have to do it.

4-5 years of age with any concerns is more than enough reason to go out and buy it. I'm parroting others here, but would saving yourself that $100-$200 or whatever the cost of the battery is for a few more months worth the potential of getting stranded somewhere? Where, if you're lucky you might get it running enough to get home with a jump start from a passing "good Samaritan"? Or worse, need it towed to a shop, pay who knows how much for the tow. And then, in either case, pay for a new battery anyway?

 

I will summarize this: https://batteryuniversity.com/learn/...and_resistance

A battery can have good cranking amps and be bad.
A battery can have good voltage and be bad.
A battery can have good reserve capacity and be bad.

It sounds as though an auto OEM will warranty around 65% of either CCA or RC. The problem here is the tool did not give you a number for RC (reserve capacity). The tool only supplied the word "OK."

It seems the reserve capacity is the greatest mystery in the measurements because that fancy tool is measuring the resistance inside the battery. Also, generally, people do not understand resistance as well as having high enough voltage or enough cranking amps.

So lets say we are all getting old here... When we are young we can throw 10 hard punches in a row. When we get old we can still throw a hard punch, but maybe only 1 or 2. This would be the same as our cranking amps staying high, but our reserve capacity is shot...

I know everyone is saying "just replace it" and I agree with them. I also think it's good to self educate to understand just what's happening here. Enjoy!

 

Mr.Cycling, incase any of this fell on deaf ears, or blind eyes, I'm following you around on here and appreciate the information, as always.

 

Ok, here's some follow-up for anyone who cares.

The battery that prompted this thread finally died this week. It had been installed in Jan 2015 (I found an old post I had made back when I got that battery). So it lasted 4 1/2 years--and 3 months past when the dealership service guy had advised that it should be replaced (although the other tests I had done didn't look too bad).

It died without any warning. There hadn't been any hesitation or other problems with starting the motor. It was just completely dead one day when I tried to start it at home.

 

Well, at least it died at home.