Electricity Cost Per Charge = 4.4 Cents
Electricity Cost Per Mile = 0.22 Cents (over 4 miles
per penny)
A common question is how much electricity does it take
to charge the battery. To the right we have a charge
rate graph. You can click on the graph to see a larger
version. The chart shows how much power is being drawn
from the 110VAC outlet during the charge cycle. Each dot
represents 15 minutes of charge time. Charging occurs in
two steps, these are known as bulk charge and float
charge. The first step takes about 5 hours as you can
see on the graph. This is where the majority of the
charge occurs. At this point the charger steps down the
power for the remaining 20% of the charge cycle.
Average power utilization can be calculated by adding all of
the plot points
together and dividing that number by the
number of plot points. In this case we take 13 and divide it by
our 24 plot points for an average power draw of 0.54
amps. Watts equal voltage times amperage so we multiply
110 X .54 to get 59.4 watts. Our charge time is 6.25
hours so we multiply the average power draw of 59.4
times 6.25 to get .371 kilowatt hours.
In California, PG&Es baseline rate per kilowatt is $.12
(as of August 2008). Multiply this rate (.12)
times the total watt hours used (.371) to charge the
battery and we find that it costs about 4.4 cents to
fully charge an exhausted battery. A fully charged
battery has range of 20 miles with this model so we can
see that it costs just 0.22 cents per mile for
electricity to operate this scooter. |
