Electric Vehicle Battery Costs Per Mile
Posted by Max Dunn Fri, 29 Feb 2008 04:44:00 GMT
When companies talk about electric vehicles costing pennies per mile in electricity costs to operate, they are being truthful. However, with current battery costs and lifetimes, the battery replacement cost in an electric vehicle will be more than the electricity cost. Let’s look more closely at this.
First, let’s look at a real-world scooter cost. The electricity costs just $0.01 per mile [1], but the batteries are likely to cost about $0.08 per mile.[2] So in this case, the batteries will cost 8 times more than the electricity cost.
Next let’s look at the Miles NEV (low speed). The Miles EV site states that the vehicle has a range of about 50 miles, and that the battery pack will go about 25,000 miles.[3] This is probably assuming the average trip is half of that, 25 miles, which makes sense since a good AGM lead-acid battery will last about 500 half-discharge cycles. They use six 12v, 150 Ah AGM batteries, which cost about $300 each, or about $2000 for full replacement.[4] This works out to $0.08 per mile, which is the same as we saw above for the scooter.
Finally, let’s look at real-world experience with the RAV4-EV. These vehicles were first available in 1997 so some have been on the road for over 10 years and are approaching 100,000 miles, so we have some long-term real data on them.[5] RAV4-EVs cost about $0.03 per mile in electricity.[6]
It is expected that these NiMH batteries will probably be able to go to 150,000 miles.[7] This bears out in real-world experience since there are some people that have driven over 100,000 miles in their RAV4-EV and haven’t had to replace the batteries. Since there is no battery after-market yet, we can’t get a good price on what it would cost to replace them. In general, NiMH batteries should cost about $400/kWh of capacity, or about $11,000 for the 27.4 kWh pack. To look at it another way, in 2004 a RAV4-EV cost $42,000 and a regular RAV4 cost $25,000 [8], for a $17,000 difference. If $5,000 of the difference was for the extra electrical stuff, then $12,000 was for the battery. So a $12,000 battery pack that can go 150,000 miles will cost $0.08 per mile, same as before.
Now there are many factors that can cause a battery pack to die early. Frequently discharging it all the way down, hot conditions, or leaving it uncharged for long periods of time can cause some battery technologies to fail early. But there are also factors that can increase the life: in particular, short trips. Also batteries keep getting better and better so we can expect longer life times for batteries.
So for the present, we can conclude that battery depreciation in an electric vehicle will cost about $0.08 per mile.
References:
[4] (AGM battery cost Reference needed)
[5b] RAV4 EVs Motor Past 100,000 Mile Mark
[7] Advanced Battery for Electric Powered Vehicles (Page vii)
Well, this is just sad news. I have been under the impression that we’d get to save the world more now at the eve of electric cars.
Here is another data point on RAV4-EV batteries. Marcos Peixoto reported on the RAV4-EV mailing list that:
This $4,700 price is probably what Toyota was charging back when they were making the RAV4-EV and reflected their cost back then, even though this is a lot lower than we can get today.
Another indication that the latest batteries should last 10 years and 150,000 miles comes from a report in the April 2008 edition of Forbes. This article reported that GM engineers are testing lithium-ion batteries to prove that they can meet this standard for the Chevrolet Volt.
There is now a company that is providing replacement batteries for the RAV4-EV and charges $14,000, so this close to the $12,000 cost I estimated above.
Lion Electric Vehicle Lithium Upgrade
Toyota is contracting with BatteryMD to provide replacement batteries for the RAV4-EV. The cost is supposedly $15,000.