It sounds like you simply need to clean the fan and ducts. These are prone to get clogged up and then you get the symptoms you describe. See pictures in this post here: Fur and dirt causing major battery problems | Page 2 | PriusChat
I had the same experience a month or so ago. I was stopped, and all of a sudden there was this strange loud noise coming from the back seat. I eventually determined the location (mystery air duct) and inferred the source (is there maybe a battery fan?) and after some research feared the fan was dirty, the battery was fried, etc. I just cleaned the fan today at 125,763 miles. A light coating of fairly tough grime, probably no effect on fan performance, I used a 1/2" bottle brush to go down between the blades and out the back of the fan to make it squeaky-clean. Probably could have been done without removing the fan if you were careful to suck the dislodged grime out of the ductwork with a Shop-Vac or some such. Would really pay to have a bunch of replacement trim fasteners handy. Sound has never occured since, Basic "Torque" battery data looks good, I guess I'll stop worrying, although I did price a replacement battery today just in case, and was pleasantly surprised at the price for a rebuilt battery with a 3-year warranty.
Don't go with a rebuilt battery. There are not enough 2nd hand modules of good enough quality in circulation to build a reliable "re-built" battery pack. Buying a rebuilt is a crap-shoot, at best. Just MHO, YMMV.
I had heard a lot of that around, and I'm not needing one yet, but I'm doing my research and comparing Toyota/$3800/1yr warranty vs 3rd-party/$1275/3yr warranty and thinking the odds are pretty good. We'll see.
Compare a 1 year warranty from Toyota that you will (most likely) not need vs a 3 year warranty where the battery craps out within the the first 6 months but you get a replacement battery, so life is good, Then that one craps out within 6 months but now no one answers your phone call/email/text. Which option would you prefer?
If Toyota's "new" battery carried a new warranty, I'd agree with you.But I can't see paying 3X the price for 1/3 the warranty. The one I'm looking at seems more than just rebuilt from parts lying around. But I'll see what the situation looks like when/if mine actually fails.
true, but the important thing is that a new battery will almost surely last way more than 3x a rebuilt, warranty or not. if you think you have a good chance of hitting the lottery, bon't buy a new battery. we have never had anyone come back and complain about early failure.