The 36V NiMH battery pack on the WE bike is nearing its end so I am looking into a replacement. Before just signing up for another pack I thought I'd try to do something more elegant. Previously I asked about better battery storage and received numerous helpful tips here. Now what I'm wondering is there a battery pack in a plastic shell like the ones that come with the LashOut or BionX that would work with a generic motor and controller? The BionX is great, but I think there is some complicated interaction between the batteries and the other components that would make it unsuitable. The LashOut is out because it is only 24V and I find SLA unacceptably heavy.
What I'm looking for is something more rugged and more water resistant than the typical brick-o-batteries in a bag. Also I dislike the charging port and the switch dangling on the end of their wires. I have already lost one battery pack to this configuration. (Oddly enough it was fused, but the 15A fuse didn't pop. Eventually one of the legs of the fuse melted off after it was too late.) I figure one of the bikes that come with nicely packaged 36V batteries would be ideal. I just don't know which one. I don't mind doing some minor fabrication to get it attached to the bike.
Dave,
I feel your pain. I am in the process of changing from Lead to something better. I have chosen to use the DeWalt battery packs. I have 4 of them to give me 33-volts @ 8.8 AH. My old pack was a 36-volt 12 AH Lead pack, of course you can only get 6 AH from 12 when using Lead. One time I ran them to 8 AH and I think it almost killed the pack. At 2.5 Lbs each 4 packs will be 1/3 the weight of the lead I was using so the drop in nominal voltage from 36 to 33 should not be a problem, I hope. The bike could reach 23 MPH on the flats with the lead so I am hopeful I will still be able to maintain at least 20 MPH with the DeWalt Packs.
When I compared the cost of NiMH with the DeWalt Lithium I was convened the Lithium would give me longer service and more miles for the cost. I even wrote a computer program to simulate the different batteries. The program indicated about a 14% savings using the lithium over the NiMH.
Hope this helps,
Chas S.
My Bicycle Pages
I have a couple DeWalt packs and they power a WE 36 motor just fine.
I was just looking at http://ecospeed.net/ ... they have an interesting drive kit meant for recumbent bikes. But they also have a boxed LiIon pack you can buy separately. These aren't the "safe" LiFe chemistry, but the potentially explosive other chemistry. Maybe that's why it's such a sturdy box ;)
- David Herron, http://davidherron.com/
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Thanks for the help, gentlemen. I suppose with the non-Fe lithium chemistry you are putting your faith in how the pack was constructed and how good the BMS is. Bionx falls into this camp, and I have never heard of a problem. I notice electricrider in Lawrence is selling a big-assed box full of Lithium Ion which fits the bill except I'd need a second mortgage to afford it, and I believe it is scaled for an X-5 motor. Way overkill for me. Maybe I should just bite the bullet and go the Dewalt route. Or maybe I should procrastinate some more and someone will start marketing the LiFePO chemistry in a more friendly package.
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Full time ebiker
BionX and Wilderness Energy
"we must be the change we wish to see in the world"
Dave,
I bit that bullet, and I am trying to build a pair of battery mounts that can be placed on either side of a bike rack, front or rear. I hope to have this setup finished in about 2 weeks as I must work on it between work and school. I only have 4 batteries but I will build the mounts for 3 on each side for a total of 6 batteries. The mounts will be wired so you can use any combination of batteries from 1 to 6. With any luck I will be able to give everyone a report on how my idea works very soon, and of course photos of my contraption.
Chas S.
My Bicycle Pages