Came accross the new battery from Antigravity UK could be of interest to weight savers at 600 quid;
In their words;
The RS-20 weighs only 10 lbs, puts out an incredible 1000 Amps, and can easily start a 900 Horsepower Big-Block V8! Yet it has a very compact footprint at L 9-1/2” x W 6.8” x H 7.5”.
Compared to a Lead/Acid Battery the RS-20 is roughly 70% Lighter in most applications. In Race use it can offer as much as an 80% weight reduction. This equates to roughly 25-40 lbs of instant weight-loss just by changing out the Battery! That makes it the most cost effective weight-loss product hands-down. To save this much weight in Carbon or Titanium parts would cost over $10,000 dollars. So enjoy better handling, shorter breaking distances, better acceleration and better gas mileage with the RS-20 Lithium-Ion Starter Battery.