Electricity Cost Per Charge = 26 Cents
Electricity Cost Per Mile = 0.66 Cents
(about 2/3 of a 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 7.5 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 44 and divide it by our 40 plot
points for an average power draw of 1.1 amps.
Watts equal voltage times amperage so we
multiply 110 X 1.1 to get 121 watts. Our charge
time is 9.5 hours so we multiply the average
power draw of 121 times 9.5 to get 1.149
kilowatt hours.
In California, PG&E’s baseline rate per kilowatt
is $.12 (as of August 2008). Multiply this
rate (.12) times the total watt hours used
(1.149) to charge the battery and we find that
it costs about .14 cents to fully charge an
exhausted battery. A fully charged battery has
range of 21 miles with this model so we can see
that it costs just 0.66 cents per mile for
electricity to operate this scooter. |
