speaking of the Varta Battery. We have the same battery in the Lotus Evora - almost everyone in the Lotus community have switched this 40lb battery to a Lithium Ion Iron Phosphate batteries that weight less than 5lbs. I use this one:
http://shoraipower.com/lfx36a3-bs12-p126
if you live in a cold environment - i would not change the battery to a lithium Ion battery like the one above - in really cold weather it does not perform well
originally i bought two of them and wired in parallel - but I have had only one in it for over 2 years now. It has the same properties as our HV battery. One of the great things about it - is that it keeps its charge - I have left the lotus for 6 weeks with no trickle charger and had no problem starting right up. Obviously it weigh less which on the 3000lb evora matters more than the 5400LB Karma.
I wonder what the parasitic loss is for the Karma.
On another note - I would love to start a "weight loss thread" - what can we do to realistically reduce the weight of the karma.(no I am not changing the roof)
My first thought would be lighter weight rotors. and unsprung and rotational mass. given the weight of the car I wouldn't want to mess with the wheels, and i am sure the tires are pretty light weight as is.
i once heard that for every 20 lbs of unsprung weight reduction, you may apply a "theoretical" gain of 17 horsepower. and that rotational mass reduction would be even more
just curious