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Things to consider about claims to Range, Speed and Performance supplied by Manufacturers and Sellers of Electric Vehicles. Last Updated: 01/31/2013 |
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1. Unless otherwise stated - assume that all Performance Information is when the vehicle components are in 100% working order and new, such as the Batteries, Motor, Controller and all other components and when the vehicle is driven in ideal conditions. 2. Do some Calculations on the Batteries used, and their "Amp/hr Capacity" ratings.
Example:
If the Vehicle is using (16) 12 Volt 100 amp hour
batteries than you theoretically have 16x12x100=19,200 Watts of
Available Energy. In reality you need to factor Energy losses in the
Batteries, Electrical Systems and Vehicle resistance to calculate the
actual available energy. With typical batteries you my actually get
about 50% of the useful "Available Battery Energy" Per Charge and then
factor about 20% system Efficiency losses. This will leave about 7,680
watts of "Real" usable delivered energy from this battery pack.
Now, if the vehicle claims to have a 100 mile range, consider this calculation:
A typical Small Aerodynamic Vehicle, at best, requires
about 10 hp to maintain 60 mph on a perfectly flat, straight road. This
would require about 10x746=7,460 watts. The distance traveled would be
60 miles in one hour. With a real 7,680 watts of "Battery Energy" it
would be impossible to go more than 60 miles at this Horsepower
requirement used. You would really need to do some good testing on the
vehicle to determine the actual Horsepower required to maintain 60 mph.
3. The Charge rate and Total time to charge a "Battery Pack" should also be calculated.
Example:
Using the same battery pack above and 50 amp hours has
been used from the batteries and the "Charger" can charge at 20 amp/hrs
then it would require at a minimum 50/20=2.5 hours to Charge your
battery pack. Of course batteries can not really be charged at this rate
thru the whole re-charge cycle, so it would require much more time to
re-charge in reality. |