# Calculator: How Long to Charge an EV

Updated: 3/9/12

 This is how much power my Nissan Leaf draws during a nightly charge.  I'm using a TED 5000 to track EV charging energy used.
Here's a spreadsheet that I created to do some rough calculations on Electric Vehicle charging, like finding the cost to charge, watts per mile, and the range per hour of charge.  Simply enter the Range (miles) and Battery Capacity (kW/h) of the car you want to solve for in the Yellow cells and see the resulting calcs.  Feel free to change the assumptions such as energy cost, charge voltage and charge amperage too.

What this calculator doesn't do is account for the capacity that an automaker might be guarding to protect the battery.  For instance, even though a battery has a given capacity, the automaker may not allow the entire capacity to be used in order to protect the batteries from damage via over-discharge.

If you find errors or have suggestions, please let me know!  If you save the spreadsheet as an Excel Spreadsheet, you will be able to see the formulas that I used.

Notes
• The Nissan Leaf and Chevy Volt only charges at 3.3kW/h at Level 2 (220V), so you need to enter 15A for the charging current to see more accurate estimates.  The Ford Focus and Coda Sedan charges at 6.6 kW/h, so you would enter 30A for the charging current.
• The Chevy Volt has a 16 kW/h battery, but limits the use (via software) between 30% and 85% of capacity to prolong battery life.  Therefore you should figure to recharge only 8.8 kW/h.