PSA: Change your 12 volt battery every 4 years

I don't think you understand the problem with your so called test so I'll explain. Since new and charged battery has 12,8V, the inverter puts out 14,3V that means you always will have a speed difference in closing windows. That means you will mark every battery as bad, even the new ones.

 

I'm not so sure that is good advice from an economic and environmental aspect. I have never had a battery last me less than six years and I live in the northeast. Some I've had, have gone 8. Do we really want to over-consume like that? What's the point of buying a Prius in the first place?

In a warm weather state like Florida, if your battery went dead overnight with no warning, you more than likely left a dome light on (I did it once).

 

There is a simple way to know if the 12V is dying with out doing anything but listening. When you turn off the car you ever notice that buzzing sound you hear from under the hood? When it starts to sound like an old dial up 56K modem you will be needing a new 12V very soon. I remembered hearing that particular sound about a month before the twelve volt died.

 

Yes, 42-48 months for a 12V battery has been my experience in a hot climate. According to the US map below, even that's optimistic:

http://www.tiresplus.com/img/global/TiresPlus-Battery-BatteryExpectancyZone.jpg

 

Well, I live in one of those red areas and have had a few brand new cars and each battery lasted over 5 years. Kind of disproves that theory.

 

now THAT is, with all respect, nothing but BS/
I live in the 'hot zone' in New Mexico & have the same battery in my GTO since 138 month (that's 11 &1/2 years).
the battery in my wife's Subaru is 90 month (7 &1/2 years) old.
the last time I checked them with a load tester was like a couple month ago: both showed perfect numbers.
it would be an odd coincidence that I just have two freak batteries which last so long....

BION
StarCaller

 

nope, you still get 12 months pro rated, no matter where you live.

i suppose if you're going to give people battery advice to help them not get stranded, a map like that is useful. fortunately, for those savvy enough to keep an eye on things, batteries, and many other products subject to wear and tear can last a lot longer than 'average'.

 

urban myth or just your own theory ?

 

Sears actually has a craftsman meter on sale for $10...

Sears.com

 

best thing would be you let optima know about all that things:
[email protected]

looks like you know more about their batteries than they do/

 

That misses the point. Of course there'll be a difference in speed even with a good battery, as you say. However, the difference will be much more obvious with a battery that's on its last legs---even if its open-circuit voltage looks OK.

 

AGM batteries are sensitive to overcharging. Yes, Optima already knows about it, so their smart battery chargers have multiple AGM settings (as do other brands):

OPTIMA® Battery Chargers |OPTIMA® Digital 400 and Digital 1200 12V Performance Battery Chargers

 

After four years? Even on cars which crank the engine to start, I've generally kept batteries at least six years or longer - until they start having starting trouble. And I live in cold Wisconsin.

The Prius is different, of course, because the 12v battery is not used to crank the gas engine, but to run the computer and other electronics. I put in a new 12v battery after around seven years (bought it from the dealer) because it was at about half capacity, and used the old 12v battery for solar storage for the last year. (It died only yesterday, after powering our living room lights over the last year.)