Hi,

I bought 07 Prius package #5. I have drive about 50 miles and runs great.
I have noticed that on regular interval the battery makes a noise (like a trrrrrrrrrrrrrrrrrrrr) for 1-2 secs or so and then goes away. Mostly it happens when I apply brakes, I drive for few minutes without applying brakes and then apply the brakes I would hear that noise for 1-2 secs. I checked with the service department, but they say it is normal. It is hard to belive if that is the case. Does anyone hear such noise. It does annoy me.

-Thanks

Sachin

Batteries don't make noise, the noise is something else.

I am not 100% sure if it comes from the battery or the battery sustem under the hood, but it does come from drivers side behind the steering and thats where the battery-system is.

Could it possibly be the vacuum pump keeping the brake system in check?


Did they move the batteries for the 07 models?

I get a sound like that too, but it isn't the battery. It is normal though - there's a sound to the regenerative braking that's quieter, but you're right there's a separate sound that happens on occasion that's almost like a "I'm switching modes" sound coming from the Prius. Nothing to worry about, just it keeping everything in check. You don't so much drive the Prius as ask it to do things, and it meticulously plots a low fuel usage way to accomplish that. Several gurgles and buzzes later, and you're on your way.

Prius 2006, bought September 14:

I believe the consensus is a pump for the brake system but I haven't had the sound to investigate in my NHW11, 03 Prius. I do hear the faint, coolant pump, but I've learned to listen for it.

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
Free speech, dialog and knowledge thrives without the poison of SPAM.

oh yeah i hear the sound too, its normal read the owners manual, something about putting more pump into the brakes or a cooling system is engaged.

i got around 20 km a liter when i drove a civic 5 spd using advanced hypermiler techniques
and now I drive a salvage nwh20 prius that gets almost to 25 km/l with 195,000 km to date.

I know exactly what you are talking about. I posted this more than a month ago:

http://www.greenhybrid.com/discuss/r...16.html?page=1

Apparently, it is normal. Annoying, but normal. +G

You are right gpar2000, I get exactly the same noise as you described and I get that every 3rd or 4th time I apply the brake and sometimes even while accelrating After reading this post and searching on internet , I am getting a feeling that this is normal but hard to belive that Toyota did not do anything to fix it. Every 3rd or 4th time should be atleast every 15th or 30th time..as I drive mostly in city and apply brakes quite frequently..

I hope toyota does something to fix this normal beaviour as it is annoying.

Could someone make a recording of the noise?

I have an NHW11 and have not heard this noise.

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
Free speech, dialog and knowledge thrives without the poison of SPAM.