My 93' GEO prism uses about $600 in gas a year at $2.75 per gallon... EV conversions always interest me for the car. But for 20,000 I can buy a decade of gas or small army of used GEO's. Needless to say, I will not be using this conversion. However, I did love the math - Thanks!This is from article about 'Gas-guzzler to Dual-mode EV Conversions'
| Essential Conversion Components | Lead-acid | Li-ion |
| 15 kWh battery pack | $3,000 | $15,000 |
| LAB replacement after 40 months | $3,000 |
|
| LAB replacement after 80 months | $3,000 |
|
| Off-the-shelf electric drive conversion kit | 4,500 | 4,500 |
| Miscellaneous conversion materials | 900 | 900 |
| Conversion labor | 3,000 | 3,000 |
| Total up-front cost before subsidies | $11,400 | $23,400 |
| Total 10-year cost before subsidies | $17,400 | $23,400 |
The following table drills down another level and calculates how the capital costs would likely work in the case of a typical pickup, SUV or van owner while depreciating the electric drive system over a 10-year period and depreciated the batteries over their respective useful lives... then added an imputed interest factor of 6% per year on the total up-front cost before subsidies. Finally,... factored in charging costs at an average price of $0.10 per kWh and calculated a fully loaded breakeven gas price before subsidies assuming a baseline fuel efficiency of 17.5 mpg for the unmodified vehicle.
| Estimated Monthly | Lead-acid | Li-ion System |
| Depreciation of electric drive costs | $70 | $ 70 |
| Depreciation of battery costs | 75 | 125 |
| Imputed interest on up-front cost (6% per annum) | 57 | 117 |
| Electricity for daily recharge (20 days @ 15 kWh @ $.10) | 30 | 30 |
| Total monthly cost | $232 | $342 |
| Monthly gas savings (20 days @ 50 miles @ 17.5 mpg) | 52.7 | 52.7 |
| Fully loaded breakeven gas price | $4.40 | $6.50 |
While the fully loaded breakeven gas price numbers don't look all that good in comparison to current prices of $2.25 per gallon, I am convinced that current prices are not sustainable. The following graph from the Energy Information Administration tracks the spot price of West Texas Crude from January 1986 through April 2009.