Bimmerfest - BMW Forums - View Single Post - i3: what will it cost?
View Single Post
Old 12-27-2012, 09:16 PM
anE934fun anE934fun is offline
Officially Welcomed to the 'Fest
Location: S.F. Bay Area
Join Date: May 2008
Posts: 6,807
Mein Auto: 2010 335d
Originally Posted by tim330i View Post
I don't think the details you're looking for exist. The complexity of calculating those details probably only exist at the manufacturers level and they're not inclined to give those out. I did find this article which I found interesting -

(Sighs) I was afraid that was going to be the circumstance. Although the link gave me some more food for thought. Doing some further research resulted in a possible model (modern day scavenger hunt?):

1. Based on this URL ( ), it appears the new battery specification for the Leaf is 24 kW.

2. On another part of the above URL ( ) different range scenarios are provided to give an opportunity for matching driving profile to range expectations. For this discussion, I will use the 2-cycle testing range of 73 miles/charge.

3. Taking 1. and dividing it by 2. (per the equation proposed in the URL you provided) would seem to yield .34 kWh/mile (24 kWh/73 miles). Extrapolating out over 100,000 miles would seem to result in total electricity consumption of 34,000 kWh (.34 kWh/mile)*(100,000 miles).

With a marginal cost (aka cost for the last kWh of electricity use) per kWh of $0.30/kWh, (if my model above is correct) the 100K mile operating cost is $10,200 (34,000 kWh * $0.30/kWh). I used $0.30/kWh to factor in what the rate would be given the additional electricity use for the electric car. For comparison, if Diesel fuel averages $5/gallon over the 100,000 mile period, and I manage to average 33 mpg for the 100,000 miles, I am looking at fuel costs of $15,151.

And then there is the matter of battery pack life. Lithium battery packs seem to have a charge-discharge cycle rating around 750 to 1,000 cycles. 750 seems to be the number for complete discharge before recharge, and 1,000 if the pack is charged around the 40% remaining threshold. 40% remaining would appear to translate into a range before recharge of 44 miles (73 mile range * .6). This provides an additional perspective on range anxiety - if you want a longer battery pack life, you don't want to be driving the battery pack to full discharge (or even 10% or 20% remaining). I doubt battery packs are cheap (one article ( ) pegged the Volt's battery pack replacement parts cost at $8,000; but that is just the parts cost, what about labor?). Interestingly, Nissan is touting their 100,000 mile guarantee on the battery pack (96 months/100,000 miles). I wonder if BMW is going to be providing a 96 month/100,000 mile warranty on the i3's battery pack?

It seems the more I learn, the more questions I have.... Anyhows, thank you for providing the link to the Edmunds article.
Reply With Quote