Does the auxiliary battery affect hybrid battery to discharge of a 2006 Prius?

LinkBack Thread Tools Display Modes
Old 17 Mar 2014, 02:35 am   #1 (permalink)
Junior Member
  • Join Date: Mar 2014
  • Posts: 1
  • User Status: Offline

Default Does the auxiliary battery affect hybrid battery to discharge of a 2006 Prius?

I noticed that the battery level would be blue then it would go to purple/lavender. I have about 126,400 miles. Toyota service informed me that it?s due to the auxiliary battery that was not properly installed. The auxiliary battery was installed April 2013 and for the past 3-4 weeks, I noticed that my sounds like a racing car.

Additionally, the service dept stated that the Auxiliary battery drained the hybrid battery.

Initially, when I took my car to the dealership, they informed me that they charged and reinstalled the auxiliary battery. This morning, I had to take my car back to Toyota for the same issue. The battery again went from blue to purple/lavender color and when driving the car sounds like a racing car.

If the auxiliary battery wasn't installed properly (April 2013 purchased from Toyota new), would it take this long for me to notice the issues that I am now having?
  Reply With Quote
Old 17 Mar 2014, 02:40 am   #2 (permalink)
Senior Member
  • Join Date: Feb 2010
  • Posts: 708
  • User Status: Offline


That seems unlikely. A weak aux battery can cause some strange behavior but its charge-circuit is current limited. It really shouldn't be able to affect the state of charge of the traction battery that much.

If the traction battery state of charge is changing much faster than it used to and the gasoline engine is spinning faster than before, I would suspect that the high-voltage traction battery may be degrading.

You could always try re-installing the aux battery, just to eliminate it as a problem. Here are instructions:

Also do a diagnostic check on the aux battery. Here are instructions for that:

Although it is earlier than normal for a traction battery failure, that's what it sounds like to me. Do you live and/or routinely drive in mountainous terrain or where temperatures are hot? Those are some factors that can speed the demise of the traction battery.

Do a search for hybrid specialty shops where you live. They're often better able to diagnose issues and have better availability to lower-cost, salvaged traction battery replacements than the dealership.

You may also want to join the forums at and post there. There are many, experienced Prius experts there.

Good luck!
  Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 07:28 am.

Powered by Yahoo Answers is an unofficial community for car enthusiasts. is not affiliated with Toyota Motor Corporation in any way.
Toyota Motor Corporation does not sponsor, support, or endorse in any way.
Copyright/trademark/sales mark infringements are not intended or implied.