Electric Vehicle Battery - Battery Cost and Parity

Battery Cost and Parity

The cost of the battery when distributed over the life cycle of the vehicle (compared with an up to 10 years life cycle of an internal combustion engine vehicle) can easily be more than the cost of the electricity. This is because of the high initial cost relative to the life of the batteries. Using the 7000 cycle or 10 year life given in the previous section, 365 cycles per year would take 19 years to reach the 7000 cycles. Using the lower estimate of a ten year life gives 3650 cycles over ten years giving 146000 total miles driven. At $500 per kWh an 8 kWh battery costs $4000 resulting in $4000/146000 miles or $0.027 per mile. In reality a larger pack would be used to avoid stressing the battery by avoiding complete discharge or 100% charge. Adding 2 kWh in battery capacity adds $1000 to the cost, resulting in $5000/146000 miles or $0.034/mile.

Scientists at Technical University of Denmark paid $10,000 for a certified EV battery with 25kWh capacity, with no rebates or overprice. Two out of 15 battery producers could supply the necessary technical documents about quality and fire safety. Estimated time is 10 years before battery price comes down to 1/3 of present. Battery professor Poul Norby states that lithium batteries will need to double their energy density and bring down the price from $500 (2010) to $100 per kWh capacity in order to make an impact on petrol cars.

A solution to the range problem is detailed in an article on Battery Exchange and explains how the total battery needs would be reduced by using a battery exchange or battery swap system http://www.members.cox.net/rdoctors/evs.html. This requires substantial investment in setting up exchange stations but would allow for the use of lighter batteries as they would not be required to provide many miles of use. Lighter batteries make the ecar system far more efficient and lower overall costs.

The LiFePO4 technology has yielded batteries that have a higher miles/$ over the life of the packs but they require a complex control system. The manufacture of the batteries is still being developed and is not a reliable source.

Some batteries can be leased or rented instead of bought (see Think Global).

Toyota Prius 2012 plug-in's official page declare 21 kilometres (13 mi) of autonomy and a battery capacity of 5.2 kWh with a ratio of 4 kilometres (2.5 mi) /(kW·h).

One article indicates that 10 kW·h of battery energy provides a range of about 20 miles (32 km) in a Toyota Prius, but this is not a primary source, and does not fit with estimates elsewhere of about 5 miles (8.0 km) /(kW·h). The Chevrolet Volt is expected to achieve 50 MPG when running on the auxiliary power unit (a small onboard generator) - at 33% thermodynamic efficiency that would mean 12 kW·h for 50 miles (80 km), or about 240 watt-hours per mile. For prices of 1 kW·h of charge with various different battery technologies, see the "Energy/Consumer Price" column in the "Table of rechargeable battery technologies" section in the rechargeable battery article.

Rechargeable batteries used in electric vehicles include lead-acid ("flooded", Deep cycle, and VRLA), NiCd, nickel metal hydride, lithium ion, Li-ion polymer, and, less commonly, zinc-air and molten salt batteries. The amount of electricity (i.e. electric charge) stored in batteries is measured in ampere hours or in coulombs, with the total energy often measured in watt hours.