Help Please ☹️ Quit Again While Driving

not sure how you're coming to that conclusion...

 

he is saying thati don't see any relationship between the video, and what you posted in #81. what is the charging rate of 14.1v telling us?

 

@Elisa daSilva, please note that if your Prius has Smart Key System (SKS), where you do not have to plug the key into the dash to start, then there will be "parasitic" draw of up to 300 mA. It may not be constant, but Prius, even without the SKS will draw a small amount of current in off state to maintain the system. This should not drain a healthy battery. Unhealthy battery will, however be effected and very funky and strange problems can masquerade behind a bad 12V battery. At this point you need to change the inverter coolant pump first and foremost. Then start dealing with the 12V issues. You will most likely need a new battery if you have let this one discharge into oblivion. They do not usually come back after those incidents. Do this methodically and separately so as not to confuse yourself or us here with random "tests" that may or may not lead to a conclusion. There are very simple and reliable ways to test the 12V battery in the most basic conditions with a decent digital voltmeter. The diagnostic mode on your MFD screen is not one of the good ways to go about it. The 14.1V you saw on there is after the car is in "READY" mode and the inverter is charging (or trying to) the 12V battery. That is a good thing and it means your car's 12V charging system is operating correctly. However it will be lost on a battery that will not hold a charge. Again, change the coolant pump. do not run the car without it as you will be stressing the inverter by overheating it and risking bigger, much more expensive problems. The coolant pump is there for a reason and it is not an optional component. We know it's bad. Replace it. Then we'll help you resolve the 12V issues.

 

Understood. Still, if you do not know exactly what you are doing, the posts send people off rails and believe me when I tell you, things can get off rails REAL FAST around here.

When you are ready, for the battery test and have a good basic digital voltmeter (yes, you can do it with your grandpa's analog one, but DVMs are so much better) perform these steps.

1. Charge your 12V battery. Do this either in the car our outside the car, it really doesn't matter. Use a good charger that is aware of the fact that you are charging an AGM battery. Yes, your 12V Prius battery is somewhat special and is not exactly the same as in most other cars. The chemistry is the same, however. Lead-Acid. But it's constructed very differently and has different characteristics from the regular old lead-acid battery under the hood of a '84 dodge. There are "smart" chargers out there that can charge these types of batteries properly and even revive them somewhat (up to a point, there is no magic there). So get yourself one of those and charge your battery fully.

2. After the charger thinks it's full, measure the voltage and right it down along with the note that this is right off the charger.

3. Hook it back up to the car and turn on your headlights without starting the car (this is important). Keep the lights on for a few minutes (not seconds). Turn off the lights and wait a minute or so. Measure the battery voltage again and right it down with the note that says something like "after the load test". If this test reads anything under 12V your battery is garbage. Replace it. If the reading is around 12V to 12.5V you may be okay. If it's above 12.5V after the load test, then you have a healthy battery. Try to start and drive the car now (provided you have taken care of the inverter).

4. Enjoy!

 

There have been literally hundreds of posts on here about “parasitic draw” on the 12 volt battery and it’s always the same thing.

You killed the battery. You killed it so deep and perfectly by leaving a light bulb on I it became damaged and no longer holds a solid charge. Couple that with the fact that the auto parts store seem incapable of load testing a 12 volt battery and the dealer too.

If you have a voltmeter I could prove it to you.

And 14.1 voltage is the charging voltage to the battery when the car is ON. It is a meaningless metric when chasing a depleted 12 volt battery.

And stop charging the battery directly to it in the trunk. Stop disconnecting the negative cable.
Use the front under hood jump point that’s why it’s there, measure the battery there at that front jump point it does not matter what it measures in the trunk only matters what it measures at the jump point in the front fuse box.

RTM.

 

That's called leaving a light on.

Its the exact same thing almost everyone has in common on this site that has 12 volt troubles and thats they never ever arm the cars alarm every single time you get out of the car especially in the garage. If you did the alarm would not arm if hatch or door ajar alerting you the door is ajar. Thats why they made it like that.

I figured since you were disconnecting the neg cable in the trunk you were charging in the trunk. Why are you disconnecting the negative cable for a parasitic test?

 

Forget about buying cheap on Amazon unless it is from a verified online Toyota dealer. Unless you want to be doing this job repeatedly.

Buy an OEM inverter coolant water pump, and expect to pay $120 - $160 for it. Toyota Parts Center Online is a good site to use. The part number is G9020-47031 - PUMP ASSY, WATER W/MOTOR & BRACKET.

Try and find a dealer offering dealer discounts codes. Olathe Toyota and Camelback Toyota typically offer good prices.