At what point does the battery start becoming less efficient on mpg?

<div class='quotetop'>QUOTE(johnfried @ Dec 21 2006, 04:46 PM) [snapback]365459[/snapback]</div>

When you're old and gray, and you're two cars past the Prius... somebody might notice a difference. The Prius treats that traction battery with kid gloves. NEVER stressing it in any way. It should last longer than you plan to own the car. Certainly longer than the ICE lasts in the average gasoline car.

 

yeah... you only notice it when the battery is dead.

some say it will be around 500k miles or more.

toyota tested the prius battery in a simulation that proved the battery to last 21 years.

classic prius owners who reported dead batteries.. or dying batteries (the few with defective batteries) said they only noticed when it was basically dead.. then their mpg droped by 10 or so very rapidly.. and the engine is louder all the time to make up for the loss in RPMs.

although the engine is controlled at all times, and will not redline, it's a way to pollute more.

so.. in 20 years or 500k miles, buy a new battery... if the rest of the car is still intact.

 

<div class='quotetop'>QUOTE(johnfried @ Dec 21 2006, 09:46 PM) [snapback]365459[/snapback]</div>

About 25 F and cloudy is when the Prius starts to turn into a normal car with really good gas mileage (battery power starts to go down).

 

I may have started noticing this already, at 54,000 miles. My Prius used to reach all green bars every day at the end of a long hill, and if I stopped at the red light it would cycle on/off three times to shed extra energy. This does not happen any more. Also, in the morning the battery quickly reaches two pink bars, so for a time the engine roars to pull the car on its own while it charges the battery. I have lost 3-4 mpgs.

 

<div class='quotetop'>QUOTE(V8Cobrakid @ Dec 21 2006, 05:40 PM) [snapback]365484[/snapback]</div>

In 20 years there will be no more gas and we'll either be driving EVs powered by renewable energy, or we'll have exterminated the human race in a nuclear war over the last few drops of oil.

But your traction battery should last the life of the car.