I’ve seen a few car batteries last 10 years. They were generally high quality batteries to begin with, in cars that are driven regularly and are well maintained, and have not been through deep discharge cycles (like driving around with a bad alternator or leaving lights on).
I always recommend replacement of any battery that is over 6 years old regardless of test results. That’s because the chance of sudden battery failure increases dramatically after 6 years. It can test good one day and then not start the car the next.
My wife had a car that was 12 years old, the battery in it was just over 6 years old but tested good. She was shopping for a new car at the time so I wasn’t going to replace it. She went to brunch with some friends one Sunday. Car started fine that morning, but I had to go jump start the car to get it home and replace the battery.
I suppose I should ask…was your goal to see how long your battery would last or to have a car that starts every time without fail?
I have always tried to squeeze the last drop out of a battery, just to see how long it will last. The first time it fails to reliably start the car is when I buy a new one. If necessary, I can have my wife come with one of our other cars, and the jumper cable, so I can get home. The last few times a battery went bad, I was already at home, so I didn’t even need a jump. I just took the battery out, put it in the trunk of our other car, and went to buy a new one.
It’s a lead-acid battery with liquid electrolyte that’s free to slosh around between the plates.
AGM batteries are chemically identical, but mechanically different in that they have fiberglass mats between the plates that hold the electrolyte in place.
Think of a kitchen sponge soaked full of water.
AGM batteries are also partly sealed so that gases cannot escape unless enough pressure builds up and a relief valve lets some out.
Yeah I guess I got gun shy. Many moons ago we were sitting at the A&w drive in. Car was maybe four years old so fairly new. No start. Had to call the tow truck for a jump. Everybody looking at us in a small town. It wasn’t the money for the jump. Before jump packs and cell phones.
So I look at the cost over the long haul. Buying stuff early that will eventually need to be bought anyway, doesn’t save money, just hastens the eventual expense. Now if you are lucky or unlucky depending on your outlook, you will die before having to buy a battery and your heirs will benefit. Ten years after you are gone, they will still talk about that extra $15 from sams estate that the got.
Sunday morning wisdom for the kids out there still learning to cope. And don’t lecture me on finance or accounting, I’ve had more coursework than I care to remember.
All of my under the hood batteries last about three years. We had a couple of cars with in the trunk batteries and they were still working well when we sold the cars after ten years. It seems like heat is a big factor in battery life.
Just the inconvenience factor is enough to convince me that trying to eke-out the last bit of life from a battery is false economy. When a battery is two years old, I begin testing it, and at the first sign on that test that it is no longer up to par, I replace it. My 2011 Outback–delivered in October, 2010–is now on its third battery.
That’s like the one I have except mine is orange. When the cca starts getting down to 80% of new and winter is coming, I turn it in for a new one. I tell the guy at the counter it’s still good though if he wants to put it in his truck or something.
My rider has a agm battery. It’s about 3.5” thick and the cheapo battery’s at menards are 4.5” thick? The cheapos are $35 and the agm battery’s are $120? I got it used 3-4 yrs ago and it still is working ok.
One battery on my truck lasted 12 years. Truck – at that time anyway – was only driven a couple times per week, which I think contributed to the long battery life. Along w/mild climate here. Corolla – in past used daily – those batteries tended to last 5-7 years. Truck uses a physically larger battery than the Corolla , probably makes some difference in the life expectancy.
Starter motor problems can produce symptoms similar to a bad battery.
I don’t know what the difference is except size but my lawnmower takes a motorcycle at v battery. So instead of a $25 battery that they have a pallet of, mine are $80 plus have to add the acid yourself. I’ve started to keep a maintainer on it over the winter because they only seem to last 3-4 years. I have a spare now which is another story but not car related except I drove to get it.
Teenage me had a dirt-motorcycle, 2 cycle engine. Vrooooom, big initial acceleration, very fun. It had a battery under the seat, but it was always dead. But somehow the dead battery never prevented the motorcycle from from working. Kick starter maybe is the reason. Always wondered why the manufacturer designed in a battery when a battery isn’t needed to use the motorcycle?