Typical lifetime of 12V battery...

How many years?
Sorry, I guess 5years. Just noticed your avatar.

 

Just replaced mine after 5.5 years and 222,000 miles. Vehicle has been used in FL.

 

Were you having problems?

 

No, it was at the dealer for another issue. They called to tell me that it died while they were servicing it. They asked me if I was having recent problems starting the vehicle. Told them not at all or ever. Since it was so old, I just said replace it. I had no choice!

 

I'm looking at buying one of the Exide batteries, surprisingly from a localish dealer. The total price would be about 196 which is slightly cheaper then both the oem and optima in my area. I could get the Exide for about 30 dollars less if ordered online but for warranty purposes prefer to have a local store i can return the battery to.

My 08 still has the stock battery, and so far this winter have seen temperatures as low as -5, it started right up. I did connect my torque reader before start up, and in ACC mode my volts were only reading 10.4v at this -5f temp, i did not turn on headlights for a load. Checked the volts today when the temp is 45f before start up and it was at 11.9v and 11v with lights on.

My main question is how long can a battery stay good for if not used? I know batteries sitting idle is bad, but what if it's placed on a trickle charger? Will that prevent the breakdown process? I ask this because i hate wasting money, I would like to buy it, keep it on a trickle charger, and have it ready in the event of a failure.

 

If you trickle charge it, it will be fine for a very long time but really because of the very low self discharge rate of the Exide battery (3% per month) charging overnight once a month should be fine.

John (Britprius)

 

Original battery in 08 was 56k. Mainly due to local driving. Almost 5 years exactly worth of time.

 

Just FYI- The original Panasonic 12V in my 2007 TCH is still doing fine after over 7 years of service. I have a feeling it will last another 3 years or so. Replacing a battery every 4 years seems like it won't be good environmentally speaking

 

That is fine if you are alert and can assess when your battery is about to fail so that you can take action at that time; or if you don't mind being stuck at an inopportune moment when the 12V battery decides to fail on you.

 

I very much support the eco thang, but how exactly does one get a "feeling" for a battery other than it failing via the many well documented ways documented here at PC? Does "feeling" mean: living with poor mileage and false warning codes or just total non-starting? 10 years ain't gonna happen, I'd be willing to bet BIG bucks on that!

 

If you take care of it, ten years + is achievable. My Gen 1 aux battery lasted 10+ years.

 

Yes, it is possible if you keep the 12V battery charged up and avoid driver error. This includes fully charging the battery 2x per month if you log low miles, never allowing a door to remain open or an interior light to stay on when the car is IG-OFF, etc.

 

I just replaced my OEM 12V (8.5 years old) a couple of weeks ago with an Exide Edge AGM battery (There was no way I was going to buy a yellow top Optima after all my trash talking). The original battery was still functioning adequately but I was experiencing an issue with the SKS system when locking the car with the black pad by the door handle. The car was sounding one long beep when I pressed the pad on more than one occasion, which it's not supposed to do. And no, I didn't leave the key fob inside the car. Since replacing the 12V battery, this has not happened again.

However, I changed the 12V mainly because another Michigan winter is slowly approaching (sigh) and the almanac predicts it will be a very cold one. It took me 30 minutes to swap out the 12V in ideal conditions - in my garage with all my tools on a delightful 75° day in bright sunlight. I didn't want to be stranded and faced with swapping it out on a cold, dark night in some godforsaken place in early 2014.

 

2008 prius. 46k miles. In florida. The last three years very low miles as I lost my job and my health suffered to the point I probably would not work again. That has been the case so far. I suppose my battery finally crapped out because of the extreme low driving of the car. The last time It had set for 3 days.

I did put in a yellow top Optima and am very happy with it so far. My scan guage 11 says it is at 13.8 when running along. With brakes and lights and all accessories on it drops to 13.5 . Good enough for me.

I will try to drive it around more to keep the battery happier.

 

Get a pulsing type battery maintainer/desulfator, and keep the car plugged in when not in use. End of concerns. My car sits for 2 weeks sometimes, and no problems with this method.

 

Sounds very similar to mine Jadz. I just replaced the original 12V battery in my 2005 Prius a couple of months ago, near the start of our (southern hemisphere) winter. Mine was date coded Nov-2004, so it also lasted a shade over 8.5 years.

I was watching it fairly closely near the end. It had been reading a little bit low for quite a while (12.1 acc / 11.8 ig-on) but near the start of winter it started going downhill pretty fast. One morning it was down to about 11.3 acc/ 10.5 ig-on. It still started and ran fine though, but that morning I drove straight to the parts store and bought a new one.

I've got to say, even right to the end it didn't cause me any issues. I didn't even notice a glitch in my 4.2 L/100km (56 MPG) average.

 

So, the question is, (for the 5 year and older oem users) when replacing the 5 year old oem battery what was your mpg average and after replacement, what is you mpg average?

 

Mine didn't change.

 

It will depend on how the battery is failing. In the usual case the plates get sulfated and the internal resistance goes up, so it will look like it has very small capacity. If it starts the car at all, it will not take much charging current before the charger decides that it is full and goes to float mode. That won't make any difference in the MPG as the failing battery doesn't represent an increased load.

If the sulfation has progressed to the point that there is an actual plate to plate short, then the battery will never reach the high voltage that allows the charging circuit to switch to float mode. Then the charger will waste lots of current trying to prop up the voltage, which is just going to heat in the failed battery. In this case the MPG will suffer as the 12V charger system will overheat, and that really cripples the performance of the car.

 

Four and a half yearsin SW FLorida where we have had three months straight of 90+ degree weather with wife who enjoys leaving the interior light on. Replacing today MOF and going to find a less expensive alternative than $170 @ Batteries Plus if at all possible.