Quote:
Originally Posted by BigDaddyT
if the engine runs at one rpm and it does not drive the wheels I doubt that itll take 1 tenth the effort of a road engine. While im thinking about it. I doubt you would even need to develop an engine but could just use one off a genset.
|
That's not how it works.
In order to put energy into a battery, you have to raise the voltage above nominal. (14.4 V in a familiar lead-acid starting-lighting-ignition battery) When that energy is drawn out of the battery, the voltage is at or below nominal. (12.0 V in a S-L-I) That's a 17% efficiency loss if the battery achieves one electron out for each electron put in.
Consequently, the most efficient operating strategy is to match the engine's output to the road load, leaving the battery out of the loop whenever possible. Extended-range electric vehicles do not run the engine at a single rpm. It's only for gensets, and it's even being phased out there as inverters become more common.
__________________
-
Douglas Campbell, P.E.
1986 Isuzu P'up, 177,673.8 miles.
- Hella headlights (highly recommended)
- DOT C-2 back end (also recommended)
- R-12 air conditioner converted to R-406a. Saved ozone and money
- 4.1:1 final drive converted to 3.4:1. Quieter, better mileage but it's a good thing I live in the flat Midwest.
- 9/22/2007, age 21: Still running well when reluctantly sent away for reincarnation, due to body & frame rust.
Last edited by drcampbell; 06-18-2008 at 06:08 AM.
|
