OEM 12 V battery how long do they last
- Thread starter JKroll
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Joe17
Active Member
I just replaced mine, 2018 touring, and I have a 57k miles. Lead acid batteries are generally good for 5-6 years. Mine was working fine until one day when I was leaving for work the car wouldn't power up. All the dash light lit up with a bunch of fault lights. Discount auto wanted $276 for one. Got one from costco for $140.
Car batteries may last one year or ten. With the Clarity we’ve heard from members who replaced the battery at 2-3 years. Ours lasted about 4.
You’ve been provided with the test results and a recommendation has been given to replace the battery. What would it take for you to be sure that it needs to be replaced?
You’ve been provided with the test results and a recommendation has been given to replace the battery. What would it take for you to be sure that it needs to be replaced?
Battery was shown as yellow rather than red hence the hesitation.
Doesnt look like 2-3 years is the average. Looks more like 4-6 years
Folks in colder climates probably have theirs longer. Mine is at 8 years
though it does show 151 /300I heard clarity only needs 100 CCA
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Where did I say that 2-3 years was average?
At 8 years, you’re living on borrowed time. If you’re prepared for the moment of death, ie: have a charged jump pack in the vehicle, you may have the risk tolerance to wait it out.
When ours finally failed, even the jump pack would not bring the car to life. Fortunately, this occurred in the garage and we had another vehicle to go get a new battery. Yours may not fail in such a convenient situation.
As always, the decision is yours to make.
At 8 years, you’re living on borrowed time. If you’re prepared for the moment of death, ie: have a charged jump pack in the vehicle, you may have the risk tolerance to wait it out.
When ours finally failed, even the jump pack would not bring the car to life. Fortunately, this occurred in the garage and we had another vehicle to go get a new battery. Yours may not fail in such a convenient situation.
As always, the decision is yours to make.
Robert_Alabama
Well-Known Member
I changed mine at a little less than 7 years. It was down to about 175 CCA when I changed it, but had not caused problems. I opted for the 1 year Walmart battery for $69. It will be interesting to see how that works out, but I keep a charged jump pack and jumper cables in the car.
That may or may not be true. Keep in mind that the 12V battery in the Clarity “cranks” nothing. What the battery test shows is the CCA for your fully charged battery. What it doesn’t tell you is the length of time that the battery will hold a charge.
The Clarity needs a 12V power source to turn on. What happens with batteries as they age is they lose the ability to hold a charge. If the car is driven daily a failing battery may not become apparent for some time. Leave the car idle for a few days or weeks and the problem may surface.
Keith Smith
Well-Known Member
If I had a 5 year old AGM/Lead Acid battery in *any* car it would get replaced. Period.
haha it was the orginal white battery. It looks different than the costco AGM I put in
All lights in car doing xmas. Hopefully goes away after driving some
Why did you choose to go with an AGM battery?
I misspoke .. its wasnt AGM.
I replaced the 12V battery in my 2018 Clarity PHEV in September of 2025. The car was built in October of 2017 and purchased in February of 2018. So, the battery was a month or two less than 8 years old since installed and 7 and a half years old since purchased. The battery still worked (and thr "eye" showed good and filled) before it was replaced but it nearly completely discharged earlier in the summer when we left the car for three weeks while on a trip. Upon return the car would not turn on and after using a booster battery (and a charge), the dash lights all lit up as usually happens in such circumstances. The battery capacity even reset to 55AH! I replaced the battery, even though it still worked, as a load test showed the battery was near the end of its life.
I usually would put a maintenance charger on the battery when the car was not to be used for more than a week. The Clarity PHEV draws a minimum of 25mAh when not turned on (sometimes even more when the keys are near or the status or location is checked). The size 51R battery only has a capacity of about 40Ah when new and a few weeks without turning on will take nearly half the battery capacity. Lead acid batteries do not like to sit partially charged. I forgot to put the maitenance charger on when we left last summer and I think this contributed to the battery going bad. The load test was good earlier in the year.
Thus, I recommend that a maintenance charger be used when a Clarity PHEV is left turned off for a week or more. Many modern cars use quite a bit of current from the 12V battery when turned off. My 2000 Volvo S80 has a 100Ah 12V battery but that can get discharged if the car is left turned off for month (the Volvo is always connected to a maintance charger when not in use for more than a week). Lead acid 12V batteries can last quite well if kept charged all the time.
Leop
I usually would put a maintenance charger on the battery when the car was not to be used for more than a week. The Clarity PHEV draws a minimum of 25mAh when not turned on (sometimes even more when the keys are near or the status or location is checked). The size 51R battery only has a capacity of about 40Ah when new and a few weeks without turning on will take nearly half the battery capacity. Lead acid batteries do not like to sit partially charged. I forgot to put the maitenance charger on when we left last summer and I think this contributed to the battery going bad. The load test was good earlier in the year.
Thus, I recommend that a maintenance charger be used when a Clarity PHEV is left turned off for a week or more. Many modern cars use quite a bit of current from the 12V battery when turned off. My 2000 Volvo S80 has a 100Ah 12V battery but that can get discharged if the car is left turned off for month (the Volvo is always connected to a maintance charger when not in use for more than a week). Lead acid 12V batteries can last quite well if kept charged all the time.
Leop