General rule on 12V battery life

All I know, is that IF mine hasn't officially gone bad in 4 years, I plan to replace it then anyway.

Some may say this is wasteful, IF there is much life left, but given the burden/responsibilities placed on a Prius 12 volt, and the subsequent problems that can develop if it dies and as it dies?

Well, I'm not going to worry too much about it for 3 1/2 years...but I'll replace it past 4.

I don't know how much warning it might give you or not. But I do know that whenever anyone posts almost any weird behaviors or problems arising in their Prius, the chorus starts singing "Replace or Check The 12 volt!". So I think it is likely you would get some warning.

 

i would say most wait for it to die. there aren't many stories here about people getting stranded, it's usually odd things happening, but the car is drivable. 4 years isn't a bad strategy, if you prefer convenience to expense. one thing to keep in mind, running the battery down by leaving a light on/door open/car sitting for a long time, can greatly reduce the life, and we don't know how many battery stories involve that. and some are already partially bad when purchased because the dealers don't understand the prius 12v is susceptible to these things.

 

You'll save yourself at lot of headaches and diagnosis time if you a) check it once a month and b) replace it every five years.

I had no warning when mine let go. Middle of last February we were grocery shopping; went to start the car and it powered up and shutdown down right away. Tried again, same thing. Waited 5 minutes, tried again and this time it started. Got home ASAP, checked the battery...10.9V and dropping.

Car down for a week while waiting for the battery to be shipped and then had to freeze my rear in -15C for two hours getting it replaced.

Now, on the flip side it was original...so i got 8 years out of it. Next one will be on the 5 year anniversary. For the couple hundred bucks, you'll save yourself being stranded.

Faz

 

I literally heard Clint Eastwood saying "Are you feeling lucky?" when reading the title. Treat it like any other expendable, elect a time to replace it based on your research, and just do it. What interval? Four years, five years? Depending on how lucky you're feeling.

 

punk.

 

It will last 4 to 8 years unless you drain it, then it is done. I never hear stories about the orginal battery surviving being run all the way down.

I do not plan to preemptively change mine, but it never gets cold here.

 

There is some leeway depending on how often you use the car. Sulfation and cycle limits are the main determinants of 12V battery life. I keep my 12V battery on a pulsing type (desulfating) battery tender, as my use is infrequent. It can last much longer than 4 years in that case.

 

I changed my OEM in May of this year after 4 years, 10 months (I went with the Optima Yellow Top.) I just treat it like any other preventative maintenance - better sooner than suffer the consequences.

 

With the Prius, 90%+ of the no-start incidents which are reported can be attributed to a bad 12V battery, so it makes sense to me to be proactive about replacing the battery.

I would recommend that most owners replace the 12V battery at 4 year intervals if you live in an area with winter snow and don't drive the car very much, like 10K miles annually or less. If you live in an area with mild climate and/or log many more annual miles, or at least use a charger monthly to keep the 12V battery charged up, then 6 year intervals would be OK. This advice assumes that you would like to minimize the likelihood of a no-start incident.

How much warning: if you are alert, you will notice that the cabin lighting is getting dim when you get into the car, which shows the battery voltage is dropping. Not many owners are sufficiently aware to notice this, though, so you should assume in general that you will not have any advance notice of an impending battery failure.

The answer to this question also depends upon if you are the sort of person who can think ahead, anticipate a potential problem and deal with it before it becomes a real problem, or if you think that bad things which happen to you are just a matter of fate - like being stuck on the side of the road at an inopportune time.

 

there are pics here and there. the code is a simple 6 digit dd/mm/yy or something that will make sense to you.

 

What does getting cold have to do with it ?

 

I was reading FazilHussein's post where he changes his battery in-15C weather

 

I figured the safest way to deal with this 12vdc battery "problem" was just to buy and install a "Battery Prog Brain T1" unit from Amazon. It protects the battery from discharging below 11.8 vdc by disconnecting the battery from the car if the battery goes below that set voltage. So if you leave a door open, leave a light on, or park at an airport for too long, it disconnects the battery from the car, at 11.8vdc. All you have to do to get going again is press the reset button on the unit, (attached to the battery), to reconnect it to the "reserve power" that remains in the battery to start the car. It monitors the battery voltage for you, all the time so it will also let you know if your battery is getting too old, and weak so no need to check it with a volt ohm meter. I guess my question is, if it disconnects your battery, say at an airport, I guess you would use the manual emergency key to unlock the car, press the button to reconnect to the reserve power, but would this reset any of the Prius electronics, or cause any problems?

 

Not 100% percent sure how to read the code. Patrick Wong has answered that question though in other post's here on PC.

Ron

 

I believe the worst that could happen is you would lose your presets like nav addresses, trip odometer readings, clock settings, auto window up, and some miscellaneous stuff that the ECU's record as you are driving. IMO, it would be no different than disconnecting and reconnecting the 12 volt when you change the battery.

Ron

 

I"ll go with January 6, 2013.

 

I'm changing mine when you do. If it has not gone bad in 4 years then when it gets to the 4 year mark I'm putting a new one in. Nothing like having piece of mind.

 

June 1, 2013 since the code is DDMMYY