There are always losses when taking power from the grid and shoving it into an EV's battery pack. The question is how big are these losses. Teslarati calculated digital read-outs from the dashboard of their Tesla Model S all-electric sedan and found that Tesla builds in about a nine percent efficiency loss when it comes to recharging the car. But the blog thought the Tesla couldn't know exactly what was transpiring between the wall and the battery, so it footed the bill for about $300 to install a digital submetering unit from EKM Metering.
With a little calculation, Teslarati was able to figure out after a couple of recharging rounds that the efficiency loss per recharge was closer to 15 percent than nine percent. That means that, instead of paying about 48 cents on the dollar relative to filling up an economy car (factoring in the AAA average price of $3.66 per gallon), Tesla owners are paying about 52 cents on the dollar. Not much compared to paying upwards towards $100,000 for the vehicle itself, but, hey, every cent counts, right? Get all of the details here.