Dead Battery need Help

2005 with only 19K miles? wow. I thought my 2007 bought last April with 13K miles was low mileage. I've put 10K on it since!
The low mileage may be playing a part - does it sit parked a lot or do you just have incredibly short trips?
Who did the oil change and did it take long? I can imagine a scenario where they left it in ACC mode the whole time instead of properly turning it off, which may have killed an already weak battery. When I had my car aligned I got it back with the traction battery almost completely drained, amazing what some shops don't know about the car.

- D

 

There is a 120A MAIN fuse located in the little fuse block attached to the positive battery terminal. It would be highly unusual for even a dead 12V battery to measure 0.4V. Are you sure that your meter is working properly? Try measuring directly across the battery terminals.

That is the fusible link box within the main relay/fuse box near the inverter which contains the 100A DC/DC fusible link among others. However, you also need to check the MAIN fuse located on top of the 12V battery as mentioned above.

Since you are driving the car <4K miles per year, this lack of use is the most likely reason why the 12V battery is failing.

If you can park in an area where an 120VAC outlet is available, then you can hook up a battery minder full-time or use a battery charger periodically. If not, then buying batteries from time to time is a cost to be borne, given your light vehicle usage.

 

If you have a 9V battery lying around the house, use your meter to measure voltage on that battery, as a test of the meter.

Typically the only reason that the 120A MAIN fuse would blow is that there exists a severe 12V wiring problem that caused a major short. Or the Prius was used to jumpstart another car; or vice-versa, and the battery polarity was reversed.

Most modern battery chargers will refuse to output current until the charger detects that battery polarity is correct, and that battery voltage is high enough so that the charger will not be putting current into a shorted battery. This is a safety feature of the charger.

 

I have a 2005 that the just had the 12 volt battery die. It was the original battery and it lasted 4 years to the month. I live in So CA in mild temperatures and the battery died on a ski trip to Mammoth at 7000 ft and temps in the high 20s to mid 30s. Even with that the battery would charge to 12.80 volts and if left connected overnight , the next morning voltage was about 10.4 volts. I did peel the top label off the battery to access the cells. Only 2 of the 6 were still flooded with electrolyte. I ended up buying the Toyota OEM battery when I got back to San Diego. The car has 71000 miles on it and I will not have it 2 more years, so I didn't bother with the Optima Yellow top conversion.

I couldn't get the right battery in Mammoth , so I removed the battery out of its spot in the rear fender and used jumper cables to bring it forward in the cabin so I could connect a volt meter to see what voltage the old battery was at when driving (it was 13.85V). This way I knew the charging circuit was working. When I would stop the car and turn t off the old battery would be at 12.80 volts and then you could watch that voltage just fade away within minutes.

 

Check to make sure your test leads on the meter are good by checking their resistance.

Also , make sure the meter is in DC volts function and on the right voltage range to measure 12 volts DC.

 

Your (and my 2004) Prius uses a "constant voltage" charging system that provides a very slow (and easy on the battery) charge and short trips are not sufficient to maintain the small 12v battery. Use a Battery Minder (or Tender).
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I carry a small jumper battery (it also has a light and an air pump) with me when traveling. It is inexpensive insurance (I've never needed it for my Prius, but it has jumped other people's cars (as well as my emergency power generator) several times. Just remember to keep it charged up so that it is ready for the next use.

Next time you need to replace this battery get an Optima Yellow Top (and adapter kit) from:

http://www.elearnaid.com/12vo1topraub.html

It handles deep discharges better and has a bit more capacity. Hopefully it will hold up longer in your use.

JeffD

ps. Patrick knows his stuff. Listen to him.

 

Glad to hear you're back on the road anyway. I agree with jdenenberg that a battery minder of some sort would be a good thing to do once in a while. (Monthly? Weekly? do not know, you'd have to check it periodically to see what it needs.)
One of my Christmas presents was a Battery Manager from Griot's. Pretty much identical to VDC's BatteryMinder I think. Also included in the gift was an optional quick disconnect lead which I've now permanently attached to the battery (+) terminal and ground, then left sticking up into the cargo area (see photo). I think this will be both easier and better than charging from the fuse box jump point under the hood. Maybe this would help you too? Just a suggestion!

- D

 

That's because the 12v battery was beyond bad. Sometimes a seriously failed battery will act like a short circuit, draining away any attempt at a jump start.

Tom

 

$224 ?
I hope it's just a typo for $124. Still not cheap though.

 

$224 may be a tad pricey, but I don't recall seeing anyone paying anything close to $124 for a new Toyota battery installed. They're not cheap. Neither is the Optima.