Warning Light to Take Immediately into the Dealer

Rather than pressing the lock button inside the car, I recommend locking the car with the mechanical key. If you use the key, you know it's outside the car...

 

If the inverter pump is OK now, that means, it now shows turbulence in the reservoir? Was the cause of no turbulence previously a low 12V or the inverter cooling system needed the air bled out of it ????

 

A recurring observation on this forum is that many of us who have taken our cars to the dealers with a 12 V battery in marginal condition have been given a passing grade from them. It seems that the usual dealer testing here is biased in the direction of avoiding failing a battery that has any useful life left, and not biased in the direction of protecting the customer from an awkward experience.

The sticky thing is that a lifetime of experience of how traditional cars behave when their battery is going marginal is poor preparation for the myriad behaviors that a Prius can exhibit when the 12 V battery is dying. Oddities in detecting the fob, including failure to recognize that the fob is inside the car, a whole range of odd instrument panel displays, and various other things are possibilities.

I, personally, carried out 12 V battery replacement on our 2006 Prius using the kit offered by elearnaid. While no very great skill or sophisticated tools were required, the instructions had several points of ambiguity, and the working location is actually rather awkward. Also considerable force was required at one point (although the instructions happily warned of this). If you have any doubts on this point, I think you might be better off seeking replacement by the dealer or other professional. But I do suggest that you not wait until the car is dead. Your recent episode almost certainly reduced the remaining life of the battery appreciably, and very likely you were within a year or so of it without the episode.

 

It would be very foolish to not replace a four-year-old battery that has displayed the symptoms you have described.

 

Every person who has posted on this thread has suggested replacing the 12V battery. It is annoying when people come here seeking help only to ignore it.

 

Very true.

 

I think the problem is the more enthusiastic PCers are more conversant with general car repair, electric/electronic, computer problems all in varying degrees and treat a problem like a challenge even possibly as a hobby. Where as some of the 1st time users may not even relate to what we are trying to explain. :fish2:

 

my two cents.
only charge a prius battery for 20 minutes at reduced amperage.
( the lowest setting..never "boost")

they usually recover well, unless cooked.

overnight charging at 4 amps is going to shorten the life of the 12 volt battery.

 

When charging the Prius 12V battery, I use a lab power supply set to 13.8V. The power supply has a maximum current output of 3A; hence the charging starts at 3A constant current and some lower voltage than 13.8, maybe 12.5 or so depending upon the state of charge.

The voltage slowly rises depending upon how low the battery is, and eventually the charging becomes constant voltage at 13.8 with the current flow declining over time. I usually continue this overnight, or until I note that the current decline stabilizes. Usually this will be at around 100 mA or less (if the final current is much more, then that is an indication that the battery is not in great shape.)

This process is essentially no different that leaving the Prius READY for the same period of time, i.e., the car is on a road trip. In fact it is better because the Prius will basically use constant voltage of 13.8 regardless of 12V battery state of charge (once the 12V battery is fully charged then the DC/DC converter may reduce voltage if the cabin ventilation system is not running, unless some other significant electrical load is on like headlights.)

 

10.7V is too low. That battery is nearly dead. Replace it or you will get stranded somewhere.