Replace car battery?

Joined
Sep 23, 2019
Messages
301
Location
SC, USA
Recently in good ole SC we have been having some chillier days and below freezing nights. On my daily driver (05 Honda), the cold starts have been slow, sounding like the battery is weakening. I went to AAP & OR today to get the battery checked and all their equipment told me was the battery was 'good' and showed 12 volts, not sure if that was actual or just saying it was a car battery. Apparently no one has the battery load testers that show CCA anymore, everyones is 'broke'. Long story short, I don't want to wait until my car doesn't start to replace the battery. But, I also don't want to throw out a battery that still has some life in it. What is a good way to gauge the life of the battery besides 'good' or 'bad'?
 
Make sure you take along a jumper cable. I got caught recently without one, lone way from home, without a cell phone! Wasn't much fun.
Or go to Walmart and get one for about $120.
 
If the battery has caps, a hydrometer is a good way to check it. Do you have a volt meter? Check your voltage (car off). The car should have been sitting for a while. You should see 12 - 12.6 volts. A 12 volt reading doesn’t guarantee a good battery. Then check with the car running. You should see 13.5 - 14 volts. If the voltage is fluctuating, you likely have an alternator problem. If your alternator shows steady output at 13.5 + volts, good alternator.
If your battery is 3+ years old and is slow to start your car, you likely have a battery ready to leave you stranded.
I almost forgot. Are your battery posts and terminals clean, no corrosion?
 
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I never replace a battery with preventative measures that is crazy I’ve still got an Interstate battery in our van that’s from 2007 still going very strong. My moms 2017 Camry still has to original battery. You will know when it starts to go out you will have to crank it for awhile before it starts that means it’s going bad. No reason to replace otherwise.
 
I never replace a battery with preventative measures that is crazy I’ve still got an Interstate battery in our van that’s from 2007 still going very strong. My moms 2017 Camry still has to original battery. You will know when it starts to go out you will have to crank it for awhile before it starts that means it’s going bad. No reason to replace otherwise.
Not always. The battery in my Dakota went out with no warning a couple of years ago; in mid-September, so we were still in the part of fall where the days were warm and the night didn't get overly cold. Drove home from my Mom's in the evening; it started just fine and there were no indications that the battery was going out. Next morning I went out to start it and it was, as the saying goes, graveyard dead. The ignition key chime didn't even work.
 
Not always. The battery in my Dakota went out with no warning a couple of years ago; in mid-September, so we were still in the part of fall where the days were warm and the night didn't get overly cold. Drove home from my Mom's in the evening; it started just fine and there were no indications that the battery was going out. Next morning I went out to start it and it was, as the saying goes, graveyard dead. The ignition key chime didn't even work.
That sucks I’ve never seen one do that. That’s really inconvenient to do it at that time lol.
 
A honda shouldn't require much amperage to start. Battery output vs life is a bell curve, and it sounds like you're on the steeply dying corner of said curve.

A stupid test would be to leave your high beams on for 30 minutes then try to start it. If it doesn't, your battery was bad. Most car batteries have 60 plus amp-hours; high beams take around 11 amps, so this would be ~10% of a new battery's capacity-- but potentially most of a bad one's.

I don't know why your town doesn't have a midtronics tester-- every garage should have one.
 
That sucks I’ve never seen one do that. That’s really inconvenient to do it at that time lol.
It was different. Fortunately it happened in my driveway and I wasn't blocking the Sonata so if it had to happen, that was the time/place. It didn't initially want to take a jump from the car and when I finally got it to start, it took about 10 minutes before I could take my foot off the gas and let the truck idle, and even after a drive it still wouldn't hold a charge so whatever happened it was definitely toast.
 
It was different. Fortunately it happened in my driveway and I wasn't blocking the Sonata so if it had to happen, that was the time/place. It didn't initially want to take a jump from the car and when I finally got it to start, it took about 10 minutes before I could take my foot off the gas and let the truck idle, and even after a drive it still wouldn't hold a charge so whatever happened it was definitely toast.
Dang. I wonder what was up with that battery I’ve never seen one do that all of a sudden.
 
A honda shouldn't require much amperage to start. Battery output vs life is a bell curve, and it sounds like you're on the steeply dying corner of said curve.

A stupid test would be to leave your high beams on for 30 minutes then try to start it. If it doesn't, your battery was bad. Most car batteries have 60 plus amp-hours; high beams take around 11 amps, so this would be ~10% of a new battery's capacity-- but potentially most of a bad one's.

I don't know why your town doesn't have a midtronics tester-- every garage should have one.
Honda puts the smallest posable battery in there vehicles. If his 2005 Accord is a 6 cylinder it most likely has a group 35 or 34 maybe a 24F (all three are about the same capacity), if it is a 4 cylinder it most likely has a 51R. And of course most manufacturers make several different levels of each of those batteries.

A top tier 35 would have 100 minutes of reserve capacity. That is 1.66 hours. 1.66 X 25 Amps is 41.6 Amp-hours.

A low tier 51R would have 75 minutes ( or even less ) of reserve capacity. That is 1.25 hours. 1.25 X 25 Amps is 31.25 Amp-hours.

So we can expect a new battery in an 2005 Accord to have somewhere between 41.6 to 31.25 Amper hours of capacity.

If it was one of the smaller ones and only charged to 80 % that would mean it started out with only 25 Amp-hours.

If the headlights draws 11 Amps and he left them on for 1/2 a hour that would drain 0.5 X 11 = 5.5 Amp-hours. That is a little more than 20 percent if it is one of the smaller group 51R batteries. Still, after that drain, if the battery was in good condition, it should be able to start.

I would agree that leaving the engine off, and the headlights on for 1/2 a hour, and then turn off the headlights and try to start it as a test of the battery. If it starts the battery is most likely still good. If it does not start then, replace it.
 
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You people need to watch this short video regarding battery coding. Some auto makers do it and some don't.
Failure to do this in such vehicles will lead to shorter battery and or alternator life.


Yep, that got me in my 2006 BMW 325i. I replaced the battery and it overcharged it causing it to go out again in a few months. I was not happy. One of my friends owned a BMW/Audi shop and had to use BMW software to reset it.
 
I got a Topdon battery tester during Amazon Prime days. Not sure how accurate these are but it’s been pretty close to what you would expect based on battery age of the 4 cars I’ve used it on so far. Recommends I replace our 6 year old RAV4 battery even though no signs yet of failing to start.
 
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