Ugh, I think my 12V battery's dying

life depends on a lot of factors

I think it really depends on the car, its underhood temps, the climate and the quality of the battery. One of my friends who used to live in the Los Angeles area mentioned that on both their Mazda Proteges, they'd go through car batteries every 2 years.

The OEM battery on my former 02 Nissan Maxima IIRC lasted <3 years. I'm pretty sure I never deep discharged it either, esp. since it automatically shuts off all interior lights including map lights after 30 mins. I ended up having to pay a prorated replacement fee for the battery + diagnosis of the probs I was having.

The one on my 04 Z (bought Sept 03) luckily is still ok.

 

2005 prius so a little over 2 years old
thats normal for a prius battery SKS?

 

I thought the 12 volt battery was a routine maint. item & not covered under the factory warranty. How did you get a free bat. out of the dlr.? What is "Kragen" barnd, the part #, & where do you buy one? Also, I have been told that the 12 volt bat. in our cars is like a marine battery.

One morning I was going to work & it was dark so the headlights were on. I got stuck in an accident stppage for about 45 minutes and I watched the sreen show the bat. going down to almost nothing. I learned fast not to use any accessories as they drain both batteries down when sitting in traffic. In that instance I shut the lights & car off until traffic started moving again.

 

I was under the impression that the 12 volt battery in our cars was a deep cycle type. Are you stating it's just a plain old every day 12 volt car battery?

 

Here in S. FL the average car battery lasts about 2 yrs. I started using battery tenders 4 yrs. ago on 1 car that sits a lot & so far the bat. is still good after 4 + yrs. If anyone is getting 7-8 yrs. out of a stock battery I'd love to know the secret to that longevity.

 

Your battery voltage is low. 12.6V or better is what you would expect from a fully-charged battery after the surface charge is removed.

It really appears that you need a new 12V battery.

 

Sure, radio only, and a battery less than four years old. Try it again with everything turned on and an old battery and let us know how long it lasts.

 

Re: My 12V battery died- how to jump?

On my 2006 there is a good size unpainted threaded stud with a nut on it very close to the fuse block just above the top of the cover near the rubber strip. All they're saying is not to ground to a painted part of the car. I'm curious as to one would get a jumper cable end into the small spot in the fuse block. There sure isn't much room in that little square area.

 

Re: My 12V battery died- how to jump?

The positive jumper cable is to be attached to the tab that is next to the stud inside the cover in the fuse box. You are probably thinking of attaching it to the stud and you are right that a normal jumber cable will not fit in the cavity with the stud.

 

The Prius DC to DC converter maintains a voltage of ~13.8VDC on the 12VDC bus when the car is READY. The 12V auxiliary battery is charged while the car is READY.

Immediately after you turn the car to IG-OFF, if you measure the voltage across the 12V battery, it will be at or very close to the charging voltage of 13.8V. However as you continue to watch, the voltage will decline. After about 30 min. it will be stable.

At that point, the voltage should be 12.6-12.8V if the battery is fully-charged. If much lower than that, then this shows you that either the battery needs more charging, or else its capacity is diminished due to age.

The symptoms that you posted at the beginning of this string are characteristic of a battery that is about to fail.

 

the prius battery is simply to small.. and charging it really good takes to long
so when you drive short and leave the Car standing long and have the sks system....

 

Well, you can either have the dealer replace the battery for ~$300 including labor; or you can buy the battery from the dealer's parts dept for ~$160 and DIY.

If you DIY you'll have to remove the brake power supply that is in the way, and also the ventilation duct to the traction battery.

When removing the fuse block on the positive terminal you will find that the red cover is hard to remove. Just bend the cover up enough so that you can loosen the terminal nut.

You will also probably find that it is easier to remove the negative battery cable where it attaches to the car, rather than try to remove the cable from the battery. Don't forget to unplug the rubber ventilation hose to the battery, and reinstall that on the new battery.

Good luck.

 

In that case tell the dealer to start diagnosis with the battery. It should save you several bucks worth of their time.