I'm working on a Lotus Elan project and was wanting to try one of the new tech Lithium Iron Phospate (LiFePO) type batteries as they are quite small and very light (3.3 pounds!), but before I modded the car to relocate the battery to the engine compartment I thought I'd try one out on another vehicle to see if they are really viable. Let's see...what do I have that would put a minuscule battery to a proper test. Hmm...how about a huge V twin?
So it's been about 4 weeks now that I've had an Anti Gravity YTX12 battery (about 3.5" by 5" by 5" tall) rated at 720 cranking amps (really) in the Morgan 3W and it works great. Probably only 20 starts or so thus far, but it spins the motor over faster than the relatively new lead acid battery (rated 320 cranking amps I think) that was in there before. Indicated battery voltage is fine and so far no worries. Had to make a tray adapter to keep the battery in place as it's so small it just wanted to fall through the stock battery tray!
Only down side is the cost
Here's a pic:
