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Re: Another EV bike :)

Posted: Mon Mar 10, 2014 9:58 am
by mattcarr
it certainly is taking shape now. Great work.

Re: Another EV bike :)

Posted: Tue Mar 11, 2014 9:06 am
by ChrisBarron
mattcarr wrote:it certainly is taking shape now. Great work.

Thanks, I've got the packs on a 'topping up' charge, where I'm bringing each 'layer' of 84 cells up from 4.1V to 4.2V. It's not a fast process but I'm being gentle with these cells to start off with because they haven't done any real work for a while.

Once that's done I'll hook up the controller and my ex-milkfloat motor to do a draindown test, in the meantime I have to build the voltage monitor and low voltage alarm system, but at the rate the cells are going on my low current topping off I hope these two things will converge together :)

A couple of other smaller projects are stopping me from designing the motor mount just now but I'll be doing that soon I hope. The battery boxes need some attention now too, with the balancer wires coming out of the side of the packs I think I'll need ot be careful and use at least a layer of vulcanised paper and neoprene rubber, then a phenolic sheet (or similar material) in between the three packs which will be assembled side by side low in the frame.


Re: Another EV bike :)

Posted: Tue Mar 18, 2014 2:23 pm
by ChrisBarron
A quick video of the discharger working is here

All layers of the packs are fully charged now. Bringing them up from 4.1V to 4.2V added about 10Ah at low current for nealry 20 hours. Whether that 10Ah of capacity is useful or not I don't know, it might only translate to 2Ah of useful capacity but every little helps !

Re: Another EV bike :)

Posted: Tue Mar 25, 2014 2:50 pm
by ChrisBarron
A couple of people asked me, via a Youtube video response, for details of the cell discharger. I've decided to post the details int he Cell Monitor group I started a few years ago, and which I'll be working on a bit more in order to apply the cell monitor design to the electric motorcycle project

The cell montior group, 18650 cell discharge project, is here ... %20tester/

I've got around to making the motor mount, after deciding I have enough metalwork here to do the job. I got out my old MIG welder and discovered I need to buy a new tip, shroud, gas gauge and in fact possibly a new gun.... So I'm going to look for another welder while I finish planning the mount. Welder problems again !

All of the packs are at full voltage, so while I wait to get a welder I might try a long discharge, I just need to rig up an automatic cutout so that i don't take the cells too low. Hopefully I'll have some results soon...


Re: Another EV bike :)

Posted: Sun Mar 30, 2014 3:38 pm
by ChrisBarron
I decided to take a chance with the welder and just get a replacement torch. Unfortunately it isn't completely compatible and connecting the gas line up would be a big faf, so I decided to try going gasless. Newer welding wires with flux cores are getting a good name. After a bit of setting up of the welder, (after converting it to gasless and installing the incompatible torch !) I started to get some pretty good welds and went on to making the mount.

A few pictures below....I tried to add extra metalwork to combine the motor mount with the mount for the controller.

Afterwards I slid the batteries into place to get a feel for how things fit. The side rails which would have gone around the engine are superfluous now, but I'll probably keep them because they have some useful brackets and offer an element of side impact protection to the batteries.

I just need to add a substantial torque arm, connecting the two upper bolts on the motor faceplate to a substantial bracket on the frame

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Re: Another EV bike :)

Posted: Sun Mar 30, 2014 3:40 pm
by ChrisBarron
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Re: Another EV bike :)

Posted: Wed May 21, 2014 9:56 am
by ChrisBarron
It's been a while since I posted , so....

Th enew welder torch I bought failed internally. I decided to treat myself to a new welder and be done with it. When it arrived it worked so badly I thought it was faulty, and sure enough a voltmeter on the output showed it was had AC welder internals, yet used DC welding wire and in the advert listed DC operational specs. I took the side panel off and found there was no rectification at all, the output to the torch was fulltime AC, and the torch was also live. The seller (ebay - again) paid for the return of the welder and gave a refund.

I paid a high price for a genuine torch for the original old welder I have, and it performs flawlessly with gasless wire now, I can get some great looking welds with ease.

There's a moral to this story about welders and 'buy cheap, buy twice'

So I've cracked on a bit with the mounts. I had to put the wheels on the bike and roll it out into the garden to check the alignment of the drive sprocket with the rear wheel sprocket.

Last night I had the motor securely bolted into the frame on the bench again and I spun the motor up with 36V of lead acid power. It sounded great.

I decided that for the first time I would run the motor from a pack of the recycled lithium cells. One pack of 42V caused the motor to accelerate very rapidly (much more than from lead acid batteries) and I had to disconnect quickly or the motor would have reached an overspeed. I can only imagine how much torque will come from 4 of these packs in parallel !

At the moment I'm building the battery tray and working out a way to rigidly fix it into the frame, while still making it easy to remove for service.

Re: Another EV bike :)

Posted: Mon May 26, 2014 4:05 pm
by ChrisBarron
It was bank holiday Monday, so I spent some time doing some test fitting and alignment checks.

I think the motor is a tad too low. I overestimated how much the rear shock would compress when the motor + batts + rider were in place. The swingarm is still at too steep an angle even fully loaded (at the lightest spring setting too !), so I need to make another motor big deal.

The battery tray is about as low as I dare go, and just needs some vertical front stays making up to tie it to the top of the frame on both sides, by utilising some of the existing (and cut away) side downtubes.
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Re: Another EV bike :)

Posted: Mon May 26, 2014 4:07 pm
by ChrisBarron
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Re: Another EV bike :)

Posted: Mon May 26, 2014 4:09 pm
by ChrisBarron
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