prius 2010 hybrid batteries dead at 126000km and up on atleast 3 taxis i know of

summer in texas and now airco on?
wow
no i dont think you shaved years of the HV battery but maybe some of your own years

As I recall, there is a DIN or ISO standard that limits the brake pedal effort required with a failed brake booster and this leads to the use of much softer brake pads in Europe --- with the accompanying brake dust. The semi metallic pads used also eat rotors and changing rotors with every second pad change is generally the rule. I believe that Prius uses ceramic pads in the US.

You mean connected to a temperature sensor? It's a good idea. But then again would it only be venting hot air from a hotter cabin? Perhaps the early idea of having a vent outside had some merit?

Where does the air vent out of from the hybrid battery pack? Doesn't it go outside of the car? The timing delay idea is to cool off the battery after you shut off the power system and let it run for a few minutes. I would assume when you're driving the cabin temperature would be lower than the outside if you're around +30C days even without the AC running. If the car is being baked under the sun then your only savior is the moonroof with solar cooling option.

There are several temperature sensors, which monitor the air intake temperature as well as the temperature of the battery at a few points. This would prevent the fan from blowing hotter air over a cooler battery.

The first 30 minutes after shutdown are when cooling might be necessary, if due to high state of charge. Usually, the cabin temperature is not so bad during time. However, the battery ECU controls the fan setting, and is not turned on when the car is off -- this is the design flaw.

That big vent on the back seat

quick jaunts around town fortunately

That's where it sucks from. It vents through the spare wheel section.

They designed for the biggest market and it works for the market. Taxi usage is a low percentage, yet it does work with some adjustments like Grumpy has said.

If the ECU was powered with the car off, then the 12v battery would need to be much larger and have a deep cycle chemistry. The added cost of that would be more than replacing overstressed batteries for the limited failures. Not to mention if you wanted to run fans off of the battery too.

If you wanted the HV battery to do the supplying then you have just introduced a reason why the HV battery would not be completely disconnected in a mode other than READY which is dangerous to everyone.

There is no win scenario to appease everybody, but the way it works now works awesome for the biggest majority of Prii owners.

The only better solution would be to have the solar roof option standard and have that vent the cabin and battery automatically.

lol. You're right. The lesson I have learned is never respond to a forum on New Years Eve, esp after a few beers!!!

This has nothing to do with taxis. This has to do with the fact that the battery can overheat when the car is turned off. This can happen in particular if you turn off the car at the bottom of a hill which has charged the battery to full -- something you should keep in mind given where you live.

Car batteries have been powering electric engine fans following shutoff for decades. It is a solved problem. These also have higher current draw than the squirrel cage in the HV cooling duct.

A deep cycle battery is ideal for the Prius. If Toyota would install the Optima Yellowtop as standard equipment instead of a Yuasa motorcycle cranker, we'd have a lot less to talk about here.

I believe that vent is where the air intake is, from the cabin, to the NiMH battery...then where does the air flow go to? How else would we get all that dust and hair trap in the blower if the direction of air flow is from the battery to the cabin (which really render the filter for this vent useless)?

no

I don't know how I missed it, but there was a TSB out last month that addresses EXACTLY this problem. Toyota recommends cleaning the fan every 25,000 miles for severe usage. Taxi drivers, this means you!!!

Wow! the picture of the fan in the TSB is really clogged. It looks like something you would expect to see in a beauty salon hair dryer. If something like this could kill a very expensive part and cause the car to fail, maybe Toyota should put an air flow sensor (or temperature sensor) in the battery cooling system.

Keith

One wonders why the TSB only applies to the Gen3/2010+ Prius?

(Over here, Toyota UK only offered a 60,000 mile warranty on the gen3 HV battery - which applies my car. I wonder if they only offered this reduced warranty because they knew there was some inherent design fault in the HV battery? Anybody know?)

There are multiple temperature sensors. But, just like the engine temperature sensor, by the time it gets triggered for high temperature, it is probably to late.

Probably true - the trip point for the sensors has to be higher than they'd expect a single temperature spike to be for the guy that's EVing on a hot day after parking in the sun, etc. etc. etc. What is going to kill the battery with a clogged fan is not any one spike in temperature, but just operating at an elevated temperature for tens of thousands of miles. Every degree warmer increases the failure rate a little bit. The sensor is designed to catch a single dangerous event, not a long-term dangerous condition.

Interesting! I wonder if there's an equivalent TSB for Gen 2.

Last month (?) when I asked my dealer's service dept about how much they might charge for cleaning the battery fan on my Gen 2, they had no idea. They'd never been asked that before (so they claim) and guessed an hour labor. I was just trying to get an idea vs Luscious Garage's rates. LG is unfortunately very far for me (~60 miles, 1 way).