Now Clyde, go easy on trying to paint me in any extreme corner or you might get a reputation of being an overexcited zealot instead of the thoughtful, rational person we all know that you are. And you wouldn't want that reputation..... right?
I like to believe my responses are rational and have at least a little thought behind them.
The battery in my bike must start it reliably down to well below 20F; and I have little confidence that a lithium battery will do that (note that I did not say that it would not, just that I do not have confidence in it happening). I have every confidence in the lead acid battery (specifically AGM) in the bike doing that very thing. Lead acid batteries are very robust with regard to charging / discharging rates and especially, charging / discharging limits. Drain a lead acid cell far down its nominal voltage and it will tolerate that- its lifespan may be shortened but they will take a charge and start the vehicle many more times before failing from such abuse. Over discharge a lithium cell and it is toast; the chemistry is destroyed. Same thing with the rate of charging, lead acid types take high charge rates well (again, it may damage the cell but not destroy its ability to take and hold a charge, as well as start a vehicle many times) while lithium batteries must contain circuitry to limit their charge rate to a reasonable rate.
I also have some experience in R/C use (fixed wing though and only for receiver and servo power) but more in cordless tools, and that experience has not been good. I have been through a handful of extremely expensive lithium batteries in a Makita cordless drill, often having them fail two at a time after long periods of inactivity. NiCad and especially nickel metal hydride batteries are far tougher in actual use even though their power density is less. Still, I would take a battery with 1/2 of the potential power storage that WORKED over a 'dead as a doornail' higher capacity battery anytime.
Lithium batteries seem to be performing well in cell phone applications although that took a number of years to reach the current (pun intended) of reliability and stability.
In the end, I just don't equate the high price and uncertainty (my uncertainty at least) of lithium battery performance, especially under extreme conditions, as a decent valve for vehicle starting use. As I already said, I do not think they are necessarily bad but I want to sit back and let them perform wonderfully before I jump on board. Besides, what is the big advantage? A few pounds of weight savings and smaller size? The size means nothing to me because the battery box on the bike is fixed in size, and if I really wanted to save a bit of weight on my C-14 I could force the rider to lose more than both batteries put together.
Brian
Seriously laughing out loud. Brian, the formost defender of bleeding-edge technology, shies away from LiOn/LiPo batteries. This is good. Is this a portent of a return to carbs, kick starters, drum brakes, and ahem "conventional" ignition locking mechanisms?
From my experience w/ RC car/heli batteries, I would have no qualms going with a LiPo motorcycle battery, other than the cost. If course, where I live, cold and snow are virtually non-existant.