I read this article first thing this morning, and realized I had a pretty bad understanding of hybrid state-of-the-art.
- Current production hybrids still allow for the gas engine to directly drive the wheels
- The lithium-ion battery in the Volt weighs well under 1000 pounds.
On the first point I am still sort of torn on, it seems really dumb to have the extra drive-train for 2 engines, when you consider weight to be your number one problem for staying efficient. Even with the dual drive option, you are looking at using the gas engine outside its optimal operating speed at least some of the time. On the other hand, charging a battery is extremely lossy… it seems like 20-30% is the number I read not to long ago. Running your engine at optimal RPMs, you’re still bleeding energy all over, losses when you generate electricity, losses when you charge the battery, losses when you discharge the battery. I am really fascinated by the trade-offs there, I really wish hard numbers were more available. (Maybe they are and I just haven’t looked)
On the second point, I am really impressed by the performance they are getting out of a fairly small battery weight footprint. My personal experiences with lith-ion batteries haven’t been all that positive, but I think its because sooner or later my cell phone runs dead, and I hope that preventing that will extend battery life substantially. Its also interesting to me that they aren’t really charging the battery with the gas engine, just putting in enough power to keep the battery above 30% charge, so hopefully avoiding a lot of waste in the explosion –piston -coil/magnet-wire-chemical _reaction system they have to go through to charge the battery on the road.
I am still highly skeptical when it comes to the long-term viability of a battery powered car, the article claims they are shooting for 150,000 mile lifetime on the battery packs. If they make that, I suppose it’s loosely comparable to automatic transmissions.
-Jordan
Nelsons 