Lightweight Batteries

[cRiPpLe_rOoStEr]

I've already considered to use a lighter motorcycle battery in a car with spark-ignition engine, just to run the electric fuel pump and the ECM at the start. Also wanted even to try a boat-like pull-start similar to the one used in outboard motors. Considering a stripped interior, without a stereo and some other electric features, in an older carburettor-fed vehicle could even get totally rid of the battery

Originally Posted by dcb

My main steed uses a kick starter only (with bump start backup) :P

With a motorcycle you can even get totally rid of any battery. 22lbs. out of a motorcycle also have a greater effect than 22lbs. out of a car

[sendler]

I add mass to my motorcycle when competing for fuel economy.

[cRiPpLe_rOoStEr]

Originally Posted by sendler

I add mass to my motorcycle when competing for fuel economy.

That's strange at a first sight, but a lowered center-of-gravity helps to achieve a good mileage since it reduces the effect of side winds.

[sendler]

Added mass on a motorcycle with it's high power to weight ratio improves the effect of pulse and glide. As long as there is minimal city cycle driving in the fuel economy competition, you will turn a better number with added mass.

[freebeard]

I first moved my battery to the floor of what was the back seat...without worring about fitting the battery in the small tray under the hood.

You moved the battery to center of gravity of the car. It will ride and corner better, a little more weight won't have much effect.

[oil pan 4]

I tested 4 of my AMP20 cells in serries, temperature was 60'F test voltage was 13.1v and they tested as having:
Canking power equal to 2/3 the cranking power of a new 800CCA optima red top battery.
80% of the rated cranking amps of an optima battery. (new optimas put out about 20% to 25% more CCA than what they are rated for)

So, 4 and a half pounds of lithium replaces 66% to 80% of the cranking power you get out of a 46 pound optima battery.

[Christ]

I'm used to spending up to $150 for batteries anyway (usually buy the biggest ones I can fit... or make fit), so next time I need a battery for something, I'll likely just get some A123 cells and make my own battery.

Sometimes when I'm feeling cheap, I'll swap in a motorcycle battery instead of buying a car battery for smaller cars.

[Christ]

Originally Posted by cRiPpLe_rOoStEr

With a motorcycle you can even get totally rid of any battery. 22lbs. out of a motorcycle also have a greater effect than 22lbs. out of a car

This isn't always true. Some bikes don't like to kick-start without some battery power to run the coils etc.

I had a Honda CM185T that, if you were super-special and the stars had properly aligned that morning, you could kickstart it without a battery in. Other than those rare occasions, you had to hook up something to the terminals in order to kick start it, but then it would kick off on the first try every time.

[cRiPpLe_rOoStEr]

Originally Posted by Christ

Some bikes don't like to kick-start without some battery power to run the coils etc.

I never had problems kick-starting small motorcycles without the battery.