Chris Tromley wrote: Lonnie Borntreger wrote:
>> So add 150lbs of something to the battery pack (line it with >> lead or something). That way you get the extended range of >> the advanced batteries, but don't mess with the center of >> gravity of the Sparrow. Of course the extra weight will >> reduce range a little, but not as much as sticking with the >> older battery chemistry - I would guess. > > It's not a bad idea, but I'm not sure how far you could go > with it. The density of a battery is pretty close to the > density of lead. The amount of ballast you could add depends > on how much space is left for it. > > If John ends up with Li-Ion, he might be able to put a pack > together that leaves substantial space for ballast. He might > actually be able to improve the handling of his Sparrow by > moving his cg lower and more forward. I think it's an > important consideration. Conservative driving is good, but > you can be forced into a situation where you have to maneuver > hard or crash. > > Another thought came to mind about this. Do I remember Sheer > saying the Evercels aren't very good for high current draws? > How about Li-Ion? The thunder-sky ones recommend a maximum of 3C = 300A. No mention of a short-term (over)rating. > Doesn't the Sparrow's single speed series motor draw big amps? Theoretically the big amps stay on the motor side of the controller! But then it has a Raptor 600, doesn't it? Evan.
