It started with Prius cells, back a few years ago, (which I believe are NiMH, not so great for our purposes), and lately we’ve seen Nissan Leaf cells hit the market at places like Hybrid Auto Center, here. This is a Great Thing. Not only does it give us, the backyard garage guys, some very sophisticated systems including module construction, and some very good performance cells (in particular, the Leaf cells apparently), but it’s only going to get better as more people buy cars, more parts become needed, and more people (sadly) will have cars in accidents going to the salvage market. A friend of mine found some automotive cells in Massachusetts simply by tapping into the junkyard, er, “salvage” database. They were a few hours drive away, but a good price and great cells.
What got me going on this was this video showing a guy tearing down a Chevy Volt pack:
Besides the obvious hate/envy I have for someone who gets to tear down a perfectly good brand-new Chevy Volt pack, it’s awesome that he shows all the gory details in the process.
So, yeah, all those strident opinions about short cycle life of certain types of (yeah, ok, RC lipo) cells on some of the forums? Some of us called BS then, and this proves it out. Even at a low life of 300 cycles, (if you do actually trust that number), that’s, oh, let’s say 300 days of riding. If you’re a rabid rider in a warm, dry climate that’s anywhere from 2-3 years. Almost everyone I know with a garage build has rebuilt or changed their pack within 3 years, and we’ve said all along – who knows what cool stuff will be available in 3 years’ time? Well, what’s now becoming available, and more so by the day it seems, is some really amazing battery technology. (What cracks me up is that in the last few weeks some of the most vocal and strident high-cycle-supporting posters have announced they’re replacing their barely broken-in packs with new Leaf packs… crow tastes better with a pinch of salt, take it from me.)
Not to mention, parts and pieces. In the video you’re seeing some awesome case design, cabling, as well as switching hardware that will likely be available as well as over-the-counter parts. Not to mention the availability of “totaled” cars… I know of one guy who was buying a salvage Leaf, with all it’s bits and pieces, on eBay.
Lesson learned? I will continue to basically disregard any concerns with cycle life. Also, I’ve been wanting to upgrade my pack, and this makes me sit back and wait a bit longer. I still have plenty of life in my CALB pack, and I’m guessing within a short time, maybe by winter, I’m going to have even more great options available for a pack. I also will probably forget about the risk and effort of building another RC lipo pack, it’s just too much, what with some of the performance numbers coming out of the Leaf and Panasonic.
It’s really one of the things I like most about the electric drivetrain – it’s essentially “battery agnostic”, and if you design the bike so that your battery mounting is fairly flexible, you’re not locked in to any particular (and possibly soon-outdated) type of pack.
Yes. Modular battery packs again. An idea that’s not going to die.