I've been lurking for a couple weeks here, gathering information for an ebike I'll be building. I have very little mechanical experience and even less electrical experience. A week ago the only thing I new about electricity was some trivial stuff I'm memorizing for my x-ray boards next month. Volts x Amps = Watts, etc. I know only slightly more this week, but I think I'm obsessive enough to see this through to completion. Please feel free to critique my project along the way, especially at this early stage. I appreciate any input, and other lurkers will probably learn from my blundering as well.
So far I have 2 of the 36V Dewalt (a123) batteries and the stock charger, and everything else for the bike (that I could think of anyway) will be here within a week or two. A 409 crystalyte motor mounted in a 26" wheel, a 48-72V 20A controller, a twist throttle, and a battery cord are all on order from Earl Witcher over at The Poweride Store. I plan to use my current mountain bike. A kitchen magnet confirmed it's made of steel, and I've measured the front fork. Admittedly, my ruler only shows inches and I'll probably end up crashing into Mars.
I have a lot of questions, and I haven't even started building my bike. To keep everyone's interest I've set up a competition. The winner will get bragging rights here and will receive recognition, in a manner of their choosing, on the viral video to be made after the project is completed. I'll also continue to post questions of incrementally increasing value while I build my ebike.
Each of the following questions is worth 1 point initially. Every time 1 or more questions is answered in a post, to the satisfaction of the majority of the forum, the remaining questions go up 1 point in value.
1. My first question is regarding the controller I purchased on faith. The description states that the cut off voltage is 29V. With the low dropoff rate of the 36V dewalt packs, does this mean that I could use one battery at a time and run the motor at 36V if I chose?
2. Would there be more risk to my equipment running the batteries in series, at 72V, or 1 at a time (36V)?
3. Would running the batteries in series give twice the power to the motor while leaving my potential range unchanged? To ask the same question another way: would having 72V available instead of 36V at a time give me better performance but the same range if I didn't change my driving habits (acceleration) and kept the speed at the same level I was able to reach at 36V?
4. From what I'm told, this controller and motor both use Anderson connectors and will be happy together. My battery cord uses an Anderson connector on the controller side but has none on the battery side. How is this connected to my DeWalt battery pack, and what connectors (if any) are needed?
5. My 2 batteries and the battery charger all fit nicely into my lunch pack. Would it be possible to leave one of them permanently in the charger and have them connected in parallel for easy charging while still on the bike?
6. Where can I find a walk-through (including parts I might need) for connecting these batteries in series?
7. Where can I find a walk-through (including parts I might need) for connecting these batteries in parallel?
7. Where can I find a walk-through (including parts I might need) for setting up a switch if I decide to run them one at a time?
That's it for now! Thanks in advance and don't forget to check back from time to time to see how many problems I've run into.