My Battery Died

You can probably check it right after shutting it down of, assuming that there is no charging active.

Then check the voltage. If it shows 12.1 get a new one.

Since I don't know all the details of the Prius you might want to disconnect the ground lead to make sure nothing is pulling the voltage down and nothing is charing it.

I have no idea what this will reset, maybe nothing, maybe you radio presets.

I think if you see anything less than 12.3 your looking at a pretty weak battery. If fully charged in only has 12.1 volts it very nearly dead.

 

I wouldn't worry about that voltage too much... I measured a bunch of voltages in my nearly-new Prius (see post here), and it measured 12.5 V with the car off and all doors closed, and slightly lower when putting various loads on it. Also, it depends what you're using to do the measurement - I used a multimeter, but the Nav system in diagnostic mode showed the voltage at 11.5V compared to the measurement of 12.17V (in accessory mode). Personally, I feel that judging a battery's health or capacity by voltage alone is too inexact of a science to make it terribly worthwhile.

Now if your situation is such that you really can't afford to have the battery die on you, replacing it might be cheap insurance from the inconvenience of having the battery die again. If it were me though, I'd probably wait on replacing it until the battery had really shown that it was failing by failing multiple times.

 

Dave,
When I approached my car this morning I noticed the driver’s door was ajar, fearing the worse, I got in and stepped on the brake, the light on the start button came on and the car started when it was depressed.

Is there an automatic shut off on the GIII?

For 5 ½ years and 94k miles I was very careful not to let this happen and when I traded the 04 in it still had the original battery that had never gone dead. Now after a week I let it happen to my new Prius.

Mark

 

I have a 2005 which I got in the fall of 04. So it's about 5.5 years old as well. I only have 40K on it, but I do notice my scan gauge shows about 10V, after powering down. Then it comes back up a bit (maybe 10.2)before the scan guage shuts off. It is charging at about 13.7 while running. According to the book that came with the scan guage, under 11V is not good. However, I have noticed NO problem yet. I understand of course it will just not turn on one day. Is ther ANY other way besides the scan guage to determine when it's time? I've changed a lot of batteries on a lot of cars but I've never even seen this one. Is it a dealer only, or is there a good generic battery that will fit. I'm in Germany, but hopefully can order one. German dealerships are even higher than US dealerships.

 

Use PC search mode, volumious information available on 12V Battery.

 

Happened to me with the Prius in the garage for four days. After a 2 Amp low charge for 3 or 4 hours it started right up again. Used the Jump Start connections to make it happen, after OK'ing it with the Dealer.

 

It is time to replace the battery. It's up to you - you can wait for the battery to fail, usually at an inconvenient moment; or you can replace the battery now.

In the US there is no generic battery that will fit, without first replacing the battery terminal connectors. You'll have to check your local sources to see whether the same is true in your country. Good luck.