Lithium battery for starting in an gasoline car - in cold weather

Our tests of a LP12V/60AH battery in a Chrysler Voyager. The battery was installed in 9/2012. Now it has two winters usage and about 20000 km of driving. We do not see any change in performace. The car was able to start car in -20*C last year (about 1 week of cold waether) and in -13*C this year.

The test diagram shows the performace in cold weather (around 0*C). In cold weather the voltage during the start impulse will drop as low as 8.4V. After the engine starts working, the charge voltage will increase as high as 14.6V.