Rich Rudman wrote: > It's real simple you screw up a Lion 100 amp hour cell and > you need a Scatter shield. > Over charge and you plate out metalic Lithium.. it soaks up > O2 and starts a fire, BANG!. > We will need Temp of each Cell, voltage of each cell, > some mechanisim to shunt power around from a really full > cell. And oh yea the system will need to know WHICH cell is > in trouble. > MK3s at least, maybe the MK4 with multi cell scanning. > The charger will need to have a fully programmable > memory, and some really nifty temp and amp hour tracking and > curve tracing. > Even at this... the battery control system will be impressive.
And Bob Bath replied: > Rich, before we say this is next to impossible, let's > remember that Nissan's Altra runs LiIonP batts. > Clearly they've developed a system, b/c 150 of them > were cruising CA streets on lease not long ago at 140 > mi/chg., and I read about EV-1 fires, but not Altra > fires. I think both of you are right, and make very important points. LiIon looks like a Really Good Thing for making EVs genuinely practical for the masses. But it also poses some big challenges. I *really* don't want to see any publicity about some hobbyist EV blowing up in a parking lot. Nissan has probably done their homework, something that is much easier for Nissan to do than most small operations. I trust Rich to do what is necessary to *properly* manage a LiIon pack. But it will take some time. Not just doing what's needed for management, but covering all the failure modes as well. For those considering LiIon for your EV, please research what's needed to do it right. Then do it right or don't do it at all. Chris
