Batteries

Okay I ran into this site while searching for something completely different hrmmm???
Anyone ever heard of these folks??? http://www.septechnologies.biz/

EV Batteries

For those of you who have been following this build, here are some pics of some of what I have accomplished lately.

I wanted to have the ability to remove my batteries or use various combinations for different ranges of travel. The case shown has 6-12V 9Ah batteries, I have two more that will fit directly below the case in a flatbar framework that will also support the case.
I used some jumper cables for the battery interconnections and small dia. copper tubing to make the connectors. I drilled a small hole thru the spade connector battery terminals and a small machine screw and nut to secure the homemade connectors to the batteries.

The DeWalt jigsaw case with carrying handle and hole thru to fit over the horizontal frame tube.

Here is the 60 tooth #35 Chain Sprocket mounted at the rear hub. I made a backing ring from some dense plastic and the red spongy material is made from a knee pad. I wanted something that would form around the spokes and help distribute the torque evenly.
I was worried that it would allow too much movement between the sprocket and the spokes but once compressed, there is very little, if any, movement there. I think it will work out fine.

I use 9 10-24, Low Carbon, Socket Head Cap Screws and washers with Stainless Steel Nylok nuts to sandwich it all together. On the sprocket side of the spokes, I cut two inner tube washers to fit where the sprocket contacts the hub and spokes. The inside diameter of the sprocket was a perfect fit to keep the sprocket concentric with the hub. I tightened the SHCS's carefully and spun the wheel, making adjustments until the sprocket was well alligned.

Getting 9 holes thru the sprocket, the backing ring and rubber spacer to match the spoke junctions was pretty tricky. I did a lot of measuring, head scratching and finally just placed the backing ring behind the spokes and used a pencil to mark the apex of each of the 9 spoke crossings then just eyeballed the tangent of each and drilled the holes on the drill press. It went together as planned and the bolts ended up right where I wanted them, so I think I got lucky.

Here are some pics of the sprocket.

I'm still waiting on the controller and jackshaft assembly to arrive. I also ordered some 6ga welding cable for some of the wiring, a DPDT switch for Charge/ Run modes, an ESGE double kickstand and some #35 Chain.
I'm not out of the woods yet, I've got a lot yet to do but seem to be making slow but steady progress.
At this point in time I can only hope it all works nicely together. The help of others has really helped considerably in getting this figured out, thanks to all of those folks.

Oh, I received my two NICE heatsinks from Sturdly, they will look sharp and really help keep the new controller cool - THANKS Sturdly!!!

This is the steel flatbar mounting bracket

This shows the location of the two lower batteries and the sprocket on the bike (thought I'd better check to make sure the sprocket would clear the frame ... it does, whew!)

Signing off for now, stay tuned for more backwoods inovation and shadetree mechanics.

Dave (aka MB-1-E)
The Bridgestone Project

Hey everybody,

The past few days I've been pretty busy, so didn't have a lot of time to get a much work done on the Mountain Bike.

After working with the acrylic enclosure for a full afternoon, I abandoned the idea. I got all the pieces cut and started gluing it up and then simply changed my mind.

I had a DeWalt jigsaw case that I never use and found that 6 of the 8 batteries fit inside nicely.
I cut the dividers out with a dremel tool so the box was now one open space to work with. Next, I bent some aluminum flatbar to fit inside and used small machine screws to secure it. This would keep the batteries in place within the case.

Once I got this done, I loaded it up with batteries and was able to pick it up and carry it as a unit.
I used a hole saw to cut two holes in the case so it would fit over the top horizontal bar on the bike.
Next, I bent some steel flatbar and made a strong support to hold the weight of the case and two more batteries below. I secured the steel flatbar using the existing water bottle and airpump screw bosses and socket head cap screws.

The case comes up a bit above the top bar, but doesn't interfere with pedaling or sitting comfortably on the bike.

I looked for connectors and wire at the local hardware stores and online but just didn't find exactly what I was looking for. I did order some 6ga welding cable from McMaster Carr that will go from the battery box to the controller and from the controller to the motor.

I also got some jumper cables which were fairly flexible and decided to use this wire for my interconnections at the batteries. As for the connectors, I got some small diameter copper tubing and started making my own. I drilled a small hole through each battery terminal and found some small machine screws and nuts that would secure the connectors to the terminals. I cut the copper tubing about 3/4" long, smashed one end closed to make a nice flat mounting flange. I tinned the cable ends and the copper connectors then heated them until they flowed together. I drilled a hole through the flange then removed any burrs and polished them up on the wire wheel.

I used some heatshrink at the ends to seal the insulation to the connectors and screwed the wire ends to the terminals.

It's a bit of a pain to do each one this way, but I think it will be a lot better connection than using push-on female spade connectors. Once all together, I'll coat the terminals and connectors with some nail polish to seal them.

Once set in the case, I shouldn't have to remove them, I'll just be charging them as a set.
I'll have a DPDT switch set up so I can change the two main leads from 24V series/ parallel to 12V parallel for charging with my Iota 12V charger.

I'll find a good connector that will allow for the controller leads or the charger to connect. I'll just open the case, remove it from the bike, close the case and carry it inside for charging, using the cases carrying handle.

Should I decide to later, I could divide the batteries up into two sets and make some saddlebag type cases for them, but I think this should work well, hopefully I won't need to change it.

Note: This building an electric bike from scratch is definately not for the faint hearted, there is a ton of trial and error and custom work involved and there's quite a lot to it. Those who get a kit should appreciate that most of the details have been worked out for you and only a few minor custom changes needed to make it suit one's individual bike. I'm not complaining, mind you, just trying to give some insight into what is involved in starting from scratch.
I get the satisfaction of success (or failure and having tried). I think I'll end up with close to what I want in an electric mountain bike, but it's no cake walk as I'm sure many here can testify.

Stay tuned for more, I should be getting my controller and jackshaft assembly soon.

Dave