12volt battery discarged on Prius

Which would be kept to an optimal SOC of 60%...right?

That would drain the 12v battery, not the hybrid battery...right?

Hmmm...need to read up more on ACC or IG-ON.

Thank you for all of your ideas...you all bring up some very valid explanations. Yet, I'm still concerned because this is the big battery we're talking about here...if the car is left on, even if the ICE runs to charge it, won't it keep it charged up at least 60% (or 5 to 6 blue bars)? The handful of times this has happened to me, the SOC has been at 2 purple bars...

I'm getting ready to bring it to Toyota so they can do a diagnostic test or something.

 

Re: 12volt battery discarged on Prius (discharged)

It has not been mentioned but the Prius has a screen for checking the 12V Battery. Procedure is: Power up, Push and hold display, turn headlights on and off three times., and a different screen will pop up. I believe it's the Signal option that will give you the current SOC and maximum charging status when engine starts up. Doing this check from time to time, gives one a good indication on 12V battery and alleviates getting the Multimeter out.My SOC's are always: something more than 12 when sitting overnight, and something more than 14 when charging. After a trip, the battery reads 13 to 13.2 volts. 6 cells X 2.2 volts = 13.2 volts= Full Charge. Should my battery checking procedure not be totally accurate, please feel free to update. Andyprius (strokeone)

 

Re: 12volt battery discarged on Prius (discharged)

Andy, sounds like a joke! But it works! I didn't push the brakes, though.
A Service menu comes up that gives a host of diagnose displays.
Moderators, please don't let this information rott hidden in this thread, please put it in some sticky thread.

Thanks!

frosh

 

Hello Frosh: This actually been mentioned in detail on numerous other strings by people much more concientious than I, but as you say the info gets buried in time. Making it sticky makes sense. A newbie should diligently search this site and Johns, there is a wealth of info regarding this peculiar and enchanting technological miracle. I had previously mentioned making the details on the 12VDC accessory Battery PERMANENT.

 

The Prius has a feature that on my '95 Chevy Lumina was called a "Battery Saver" (at least my 07 Prius does). If any door, including the hatch, is not totally closed the interior lights will automatically go out in 15 to 20 minutes thus "saving your 12V battery". This feature does not apply to any manually switched on lights, like the reading lights in front or the trunk light. Therefore, if you manually switch the reading light on and forget it, the battery will drain. Also, if your trunk light switch is in the ON position, and the trunk is not fully closed, the battery will drain. Therefore, the thing to do is to leave your trunk light switch in the OFF position until you really need it, and immediately turn it off when it's no longer needed. Also, don't leave the reading lights on. I have tested this feature with the door and trunk lid activated passenger compartment lights on, and it works every time.

 

Re: 12volt battery discarged on Prius (discharged)

I was able to get the screen, but didn't know what to do with it. I would like to use it to check the battery.

 

Never mind. I found it. The sequence was Menu->Display->Signal Check.