[seth1974]

Ok , big question for a big Post i Hope.

In my italian forum i'm in battle with an XXXXX ingeneer who says always " if you have the batteries down the Prius wil suffer a big performance loss , so she is dangerous . " and " i like mountains , if i drive a Prius on a Mountain rosd i descharge the batteries in few kilometers and the car it's dead , she only will move with termical engine witn bad performance "
Ok , i've tried to explain him that it's impossible descharge the Prius Batteries and that generator recharge batteries always when the CPU need more power , but he dont beleve me.
So , some one have the anwers ?
Someone can explain exactly wath's happen when the batteries are low ?
Thanks .

 

[john1701a]

> Someone can explain exactly wath's happen when the batteries are low ?

After over 73,000 miles of driving, I still haven't ever even seen my the charge-level below 1/2.

Low really wouldn't matter anyway. Even climbing up hills the battery-pack rarely gets used. In fact, most all of my climbs up out of the Mississippi river valley every evening after work, the system CHARGES the battery-pack. In short, power from it isn't even needed.

 

[frenchie]

Although it's not stricly impossible to drain the HV battery and experience a power loss in a Prius, it is extremely unlikely and will NEVER happen if you're an average driver. In other words, to deplete the battery you need to work really hard for it, like using your Prius like a race car when driving uphill to a mountain pass. And if you need to feel really secure (before attempting passing another vehicle in a situation where you need full power for instance) the multi-display tells you the battery state of charge. Now if the engineer you're discussing with needs a sports car to express himself, just tell him the Prius is NOT a sports car, but a family car with "enough" performance and great fuel economy. It does not compete with a Ferrari. So what ?

 

[Daniel]

Various people, on various Prius chat boards, have reported driving over the Rocky Mountains with no problems at all, and plenty of power.

The Prius does not depend on the battery for sustained power. It gets its power from the ICE. All the battery does is provide extra torque for acceleration, and smooth out the load under conditions when conventional cars would be inefficient, allowing the ICE always to operate within its most efficient range. (And recapture some energy by regenerative braking.)

The mistake that engineer is making is in his assumption that the Prius is under-powered and needs the battery for anything other than level roads. But this is not true. The Prius is an average-powered car, comparable to other family sedans. It is not a muscle car and cannot match the power of the more powerful cars. But it does have plenty of power for mountain driving, and it has more power than some other cars.

I think the way to convince the engineer would be to calculate how much horsepower a car of this weight needs to maintain highway speed going up a mountain grade, and show him that the 76-hp ICE is more than adequate. (I don't know how to do that calculation, but other folks do.) The extra power & torque that is available for brief periods from the battery/motor allows you to accelerate rapidly when needed. But you don't need that power continuously because you cannot accelerate continuously, for obvious reasons.

 

[seth1974]

ok guys tahnks for answers , my " enemy " today is very strong , now i paste and copy the messages on my italian forum.
The engeneer is an old cars fanatic , not classic cars , only old car. he owns a Maserati 224 biturbo ( 224 Hp for 2000 cc engine ) year 1988 , a 1984 Jeep Cherokee 4.0 V6 , an Peugeot 205 1400 cc year 1988 and a Fiat " Ritmo " 105 Tc 1600 cc Gpl/gasoline year 1984.
He belive old cars are the best in the world , and i think , is just a litte nbit tecnophobic......
Jhon , thanks for your site , i read you every week !

 

[richard schumacher]

The information at the following site may help lift your friend out of his darkness: http://www.toyota.co.jp/en/tech/environment/index.html

 

[Daniel]

When that guy says that "old cars are the best," I wonder what criteria he uses to judge?

Best in terms of mileage? Definitely not.

Best in terms of reliability? Not if compared to Honda or Toyota.

Best in terms of pollution? Only if you like smog!

Maybe he likes old cars because they are easier for an amateur mechanic to work on (but Hondas and Toyotas almost never need work) or because old cars are more likely to be over-powered (which is dangerous and expensive, but helps some men to compensate for personal shortcomings.) or maybe he just likes fixing things, as a hobby, and an old car gives you plenty of opportunity for fixing stuff. Great hobby, if you are into that, but not good transportation.

 

[Arms]

Although it's not stricly impossible to drain the HV battery and experience a power loss in a Prius, it is extremely unlikely and will NEVER happen if you're an average driver. In other words, to deplete the battery you need to work really hard for it, like using your Prius like a race car when driving uphill to a mountain pass. And if you need to feel really secure (before attempting passing another vehicle in a situation where you need full power for instance) the multi-display tells you the battery state of charge. Now if the engineer you're discussing with needs a sports car to express himself, just tell him the Prius is NOT a sports car, but a family car with "enough" performance and great fuel economy. It does not compete with a Ferrari. So what ?

Given that you want to drive uphill a relatively steep alpine road with many U-turns and curves, the Prius will probably outperform an ferrari. At least for a 530d BMW with manual transmission it has been prooven - but the performace boost is mainly due to the fact that the Prius can operate it's engine permanently at peak performance, while manual transmission geared cars loose power to the wheels with every turn, when they have to go to 1st gear, and then 2nd, 3rd, before wasting energy braking, gearing down to 1st again for the next turn...

Unless you drive for about 10 or 15 minutes a very steep highway incline (6%) at very high speed (150+ km/h) as I did once in germany, there is no need to worry about draining the battery to such a low level that the power with be reduced to the combustion engines peak power level (which, by the way, was adequate to continue climbing that stretch of highway at 140 km/h).

As soon as the road load is reduced (less incline, less speed), the battery is immediately recharged, and it takes only a few seconds to recover into a state of charge where normal performance is restored.

Richard

 

[seth1974]

Ok , thanks

for your attention , your answers are welkome !
the contest bornde by an italian magazine that tested prius and the driver wrote : " when you have batterie low you loose 8 Km/H in top speed and a 25 % in accelleration ".
Lies i know , this magazine it's no reable but a lot of peolpe read that .
Ok guy ttanhk's for your attention !

 

[frenchie]

I wouldn't say the writer was, strictly speaking, wrong... but he "forgot" to say that a completely depleted battery is something you NEVER experience when you're driving a Prius according to road regulations... :wink: