Charging batteries on EVs

#1

How many HP engine does it take to turn the alternator to maintain the charge on the batteries on an EV? 100HP? 150HP. I don’t understand why GM can’t find a power plant for the Volt.

#2
 It takes as many HP as the engineers need to provide the results desired.   Since GM seems to envision a car that will be able to travel an unlimited distance then they will need an engine that can maintain the car under typical driving situations and maybe enough to provide power for extended high speed etc.  

Making the engine small will make the car lighter and better mileage, but it also means you will take a hit on performance on long drives at high speed, so the engine likely will be a little larger than minimum needed for most users. It is difficult to get past the advertising hype but it seems they want a battery capability to handle city driving and rely on the engine for inter city highway.

In order to get the best specs on the car, they will need to carefully chose the gasoline engine to match. In addition, they may want to pick an engine designed for the specific needs of that car, which will not be the same as for a traditional all liquid fueled car.

#3

I thought the Volt was supposed to have a 1.4L 4-cylinder engine to provide charging power for the batteries and extend the car’s driving range. I don’t know the HP rating of the proposed engine.

#4

Since the engine only needs to drive a pulley to turn an alternator, would it be logical to make the motor mounts so alternate fueled motors could be retrofit with little effort. This would seem to open the door for many upstart specialty companies to provide alternate options.

#5

You could always get on the list for a Tesla roadster and skip the gas engine altogether…

The Tesla will do 0-60 in four seconds, go over 200 miles between charges, and recharge while you take a short power nap. Sweeeeeeeeeeet!

#6

All that for only $109,000.

Not so sweet.

#7

According to information on Wikipedia, the Volt will have a range of 40 miles in charge-depleting mode. I wonder if that’s really the case?

It would require about a 100 HP engine to maintain the battery during driving with all inefficiencies accounted for. If you never drive more than 40 miles between recharging at home, you’ll never use the engine. If you drive more than 40 miles between charges, 100 percent of that time will be with the engine running at maximum HP, or around 5,000 rpm, in order to maintain charge.

#8

The plan for the Volt is to have the 1.4L gasoline engine to run in the 2000rpm to 3000 rpm range.Source R+T Feb 09.