12-v. battery died

:doh: i hate when that happens. good advice for those of us who think our batteries will last forever.

 

That's what happens when you get an EV and let the gas guzzler languish.

A Battery Minder/Tender/Optimate is a good idea for the new one.

 

what is the pigtail for?? I can only guess its either to hook up a battery minder or a quick disconnect so your battery doesn't drain when sitting for awhile.

Those car accessory magazines sell an attachment for batteries so you can remove a green plug that disconnects the battery so that your battery doesn't drain and is more difficult to steal, useful for people leaving their car in airport parking lots for days or weeks on end.

 

The manual hatch release is under the floorboards in back. It's a pain to get to it with a closed hatch.

Tom

 

I'm just baffled by all the newbs that are always having 12v battery problems with the prii and replace the OEM with another OEM just to go thru another four years of the ICE constantly charging the inadequate 12v battery.
The OEM battery is a throw away unit that should be replaced with a real battery asap, in this cast the optima yellow top, the optima is a gel, deep cell battery capable of years of daily use.

 

I hope you aren't implying that daniel is a newb. Look at his post count.

Tom

 

My OEM battery is dated coded 26/11/2004 and still going (though admittedly it probably wont be for much longer). Anyway, that's over seven years old!

 

There are lithium 12V on the market, but they are hideously expensive, like $1000.

The 12V in my '04 RAV is still original and going strong after 8 years. I've let it run completely dead a few of times. I haven't even had to add water to it. It's only the POS things that Toyota sources from Yuasa or Panasonic that bite the dust at the slightest sign of trouble.

 

i can't agree with the 4-5 year thing on all car batteries. i have always gotten 7 or more years from my batteries under regular and customary usage.

 

I've replaced led acid batteries as old as 10 years old. *shrug*

 

It seems to be the Priuses that are less frequently driven that have the shortest 12V battery life. I think the Prius 12V battery management is pretty ordinary (basically just a constant 14 volts) and some infrequent drivers don't get enough charge to stop the battery starting to sulphate.

 

that sounds right, although, i have an 05 dodge truck i drive once a week for 8 miles and the battery still seems strong.

 

Yes, and I bet that if you measured the battery charging voltage on the Dodge (at high speed idle) a few minutes after starting and it would be well up around 14.5 volts (maybe even higher). Many cars force a slightly higher charge voltage onto the battery when the car is cold started, probably to rapidly replace the charge lost from sitting and cranking, and then drop back to a more sedate level after that. The prius never really "forces" the charge on the 12V battery as much as some other cars.

 

Did you notice how the other Optima owners all said it was common? <crickets chirping> Every product will have some failures, the Optima has a lot of happy owners on PriusChat, and at least one unhappy owner.

I think Optima claims it dies less frequently when deeply discharged. If you leave the dome light on overnight every 3 months, then no it is not going to last years longer, just months longer. If you do so once every other winter, yes I think it will last years longer.

Your question seems to be if I never leave the dome light on even once, will it last longer? I don't think Optima makes that claim. Those claiming the stock battery lasted 8 years are those perfect people who never do leave the dome light on. I do not know any of them personally.

 

Owned many many cars and never seen 14.5 volt charge level. What your claiming would require software and force charging is unnecessary anyway.
A car's charging system provides a fixed voltage of 13.8 to 14.4 and does not measure current draw. The battery depending on its charge level draws what ever current it requires from the alternator. But the voltage will remain constant. It has to or the regulator is blown. Or really bad.

There is nothing wrong with the charging system on a Prius as you imply.
Which is why when people upgrade to a decent battery like an Optima they cease to have any battery problems.Stop making up problems this car does not have to prove an erroneous point.

 

Seriously Ed something as simple as a two stage charger need not be software based. Plenty of simple systems were implemented well before computers were even invented. Next thing you'll be asking, what navigation software did Columbus use to discover the Americas, and was it Apple or Android based?

I had a 1992 Ford Laser and several times measured the 12V battery voltage soon after a cold start, and it was 14.5 or perhaps a little higher. The first time I saw it I did actually think that the reg may have been faulty and that it would boil the thing dry in a few days. But nope, after going for a half hour drive and measuring again it was only 13.8 to 13.9 volts, so there you go. That was an old carburetor engine and I don't think there was a ECU in the entire car, but it was probably a simple two stage charger based on water temperature or something.

Also just tested my other current car, 2005 Mazda 2. Not as dramatic but also clearly a two state charger, 14.4 volts soon after a cold start dropping to about 14.0 after about a half hour drive.

 

And you would need a special charger. Replacing the Prius 12V battery with a lithium one is likely to: A) Make a bomb, or B) Result in a $1,000 brick.

Tom