Adam wrote: >Is that last bit correct? I've seen this elsewhere, as well, and I >was wondering if it is just math, or if it is based on real world >experience? Is it really accurate to say that a battery which gets >130 miles per charge and 600 cycles gets 600*130 = 78,000 miles in >real use? How much is a "cycle?" Until the battery is 80% >discharged? If so, does a 40% discharge count as half a cycle? >Less? More?
In the world of lead acid batteries I don't think anyone (at least in modern times) had managed to get a pack in an on-road vehicle (car or Pickup) to last much more than about 30k miles. Perhaps some of the auto manufactures vehicles, but I'm thinking of conversions here. NiCads are known to last longer than you want them, in fact several of the NiCad conversions whos owners are on this list bought their packs used. NiZn is somewhat of a question mark. Pound for pound you get 3x the capacity (in a slightly larger volume - lead is heavy), and "should" get about that kind of pack life increase too. But they are quite new to the market - to new to have proved that yet. I know one pack has failed in an onroad EV, but that was due to overheating (I've heard). As I have been told, they are *very* unforgiving to that (as in - they overheat and start rapid self discharge, that keeps them hot until they are dead, they won't take a charge again, buy some more :-) This brings up a point that many people interested in EVs are wondering. Are EVs cheaper to operate than ICEs. In power used, clearly yes. Electricity cost less than gas except a very few situations in the USA (gas has to drop in price to find them). But battery life (lead acid) eats into the ICE maintainance budget pretty quick. Like $900 to $1500 every 20k to 30k miles worth (3 to 7.5 cents per mile). Now add in a penny or 2 per mile for electricity. Compare this to gas costs for a similar size vehicle. Its not very favorable, however I think the EV wins if >1/2 your trips are less than 10 miles each way (ICE maintainance costs start to dominate, its quite hard on them). That last part describes me, and many people living in an urban setting (and some in a suburban setting). Neon
