The prices just keep falling on plug-in electric cars.

The latest to announce a new, lower lease price is Smart, which cut the monthly cost of a three-year lease on its 2013 ForTwo Electric Drive Coupe from $199 to just $139.

That's not the lowest single electric-car lease we're aware of in the U.S.--the Mitsubishi i-MiEV was offered by one Illinois dealer for just $69 a month last January--but it's remarkably cheap.

There are a few caveats. First, you have to put down $1,999 up front, which is roughly commensurate with other low-cost electric-car leases.

Second, this rate only applies to the Coupe version of the Smart electric car, not the Convertible (which is now $199 a month, down from $239).

Most important, the customer has to agree to take part in the Battery Assurance Plus program.

Under that scheme, the customer leases the car and the battery separately. Smart performs regular maintenance on the battery, warrants it for 10 years, replaces it if required, and eliminates any annual mileage limits on the car.

Smart also offers the Battery Assurance Plus program for Smart Electric Drive cars that are purchased, and cuts the car's price to $19,990.

In that case, the buyer owns a "glider" but leases the battery that makes it run for $80 a month.

Under the new lower lease price, the car is leased for just $59 a month, plus $80 more for the battery lease.

That lower price only applies to when the customer leases the battery separately. If a customer chooses not to participate in the Battery Assurance Program, but to lease the entire vehicle as a single entity (Smart says only a handful have), the price remains at $199 a month.

Smart's announcement was released the same day Chevrolet announced a whopping $5,000 reduction in the sticker price of its 2014 Volt range-extended electric car.


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