Power loss & low battery during climb

I go over Donner, probably 16- 20 times in the last 6 years and never experienced any power problems, summer or winter. I generally only drive at 55 mph as the trip to Reno is only about 2 hours. Maybe that is why ( ? ) who knows.

 

Tone my sis and i who drive trough pacheco pass on a daily and now have over 210000 miles on our 07 prius are having the same problem. I replaced 12v just yesterday with no change. So i take its the HV battery.Can you give us an update? Is your prius now running like before?

 

I'm curious, since your car is out of warranty, what are your plans? You ought to try a salvage pull from an '08 or '09 before trying anything else.

 

We'll sis went to dealership in Santa Cruz and they told her that "exhaust has a broken donut that is causing power loss". The donut broke because her motor mounds are worn out. So the estimate $900 for repair and that they couldn't tell if she was having a HV battery problem. I'm not a mechanic but does this make any sense?

 

Thanks for the update and please do keep us informed when you go back to the mountains. Thanks and good luck!

 

Thanks for the update, Tone.

 

Thanks for the update, Tone.

Many times someone posts about a problem with their car and we never hear from them again. Your posts may help others so thanks again for keeping us updated.

 

I too want to thank Tone for the latest update and all of the information on this string.

It is good information and is also very interesting to see the increase in the MPG. I hope it keeps those high numbers for you. I know there are other's with higher numbers than that.

 

A happy ending to a great story! I think you may have paved the way for others to seek warranty help when there are clear driveability problems but not diagnostic trouble codes.

 

Once again I must say "Thank you" to tone for the information. I have learned quite a bit about the Prius since my wife bought hers, but have learned even more by being a member of PC.

Also glad to hear that the problem is solved and that the MPG's are holding for you.

 

thx for al your time and information
did toyota ever get back to you what they find?
maybe the battery total capacity was just way to low after a few years of driving,

 

Liked to ask when you had the Inverter Coolant pump replaced under recall?
I was going to say I doubt its the battery as it would most likely throw a CEL. I was thinking it was either the pump or the condition of the Inverter coolant itself. I changed my Inverter coolant at 30K because it looked terrible. Los of aluminum silicate in it as it was very cloudy and had aluminm salts on the rim of the reservoir.
When I changed the coolant I got an instant bump in mileage.
In fact the reason I changed it was my mileage was tanking real bad and I noticed with my IR thermometer that my Inverter was running much warmer than usual. When the Inverter gets hot it gets very inefficent.

Think about it...its not the batteries supplying power its the Inverter's lack of power to charge the batteries under load.
And the biggest load the car will ever see is a big hill specially with ac on and some weight in the car and a low charge on the battery at start of hill.

And the dealer can check cell quality easily with the Techstream software. It came back ok which puzzled them and they started throwing parts at it.

If you had gotten out of the car when it was struggling on the hills and popped the hood and felt the Inverter I bet you would have found it to be very hot.
So I can tell you at 90,000 miles the Inverter coolant needs to be changed badly. Mostly because the heatsinks in the Inverter are high quality aluminum and thats one of the most corrosive metals in the world. It contaminates the coolant.

 

I am having the same problems with powerless I have to pull over recharge and give it another try. The dealer told me the 12 v was bad and replaced it. Please tell me what I need to do to fix my prius I don't believe the 12 v is the problem

 

No, 12V is not the problem. Thank you for providing your location, it is helpful to know that you are climbing real hills.

It is a problem with the HV battery system. Do you ever hear the HV battery fan running on high?

How many miles are on your Prius? On the chance that you are still under warranty, you could possibly be able to demonstrate this problem to a dealership technician and get Toyota to replace the HV battery. The problem is that reduced capacity HV batteries can linger for a long time before finally reversing/killing a cell.

If there are a lot of miles on the car, this might be a good time to sell it or trade it in, before the battery lets go completely. The problem is that, while the HV battery is the primary symptom, there could be a latent problem somewhere else. If there is excessive drag in the transaxle, or the gas engine is operating at low efficiency (such as clogged catalytic converter), then the battery is asked to do too much work on hill climbs, and once exhausted, there is not enough power delivered from the gas engine to the wheels to sustain momentum. Even a badly clogged air intake can cause this.