Balance Check

I have now driven more than 300km with the conversion and charged the battery pack nine times from about 1/3rd left. Everything seems to work real smooth. So I decided to check the cell voltages for any oddities, as I am relying only on bottom-balancing and there is no battery management system (BMS) used in my bike. As I went through them, every single cell of the 25 cells reported values within 0.01V from each other after driving to work and using almost 30Ah of energy. All the cells had values of 3.27-3.28V using the meter that gives a bit higher numbers than the other one I’ve used. So I’d say the pack is still in excellent balance, and there shouldn’t be no bad cells in the pack. I’d say I am now very confident with the bottom-balancing method. Also while opening the battery boxes for the inspection I added some extra insulation in the bottom pack, to make sure that the cells won’t bounce around and that the poles will have zero chance of hitting the bottom of the top box, which could potentially short circuit them.

Everything else went just fine, but as I worked in a rush, I managed to drop the DC-DC converter (stupid me) as I had to disconnect it so that I could get the upper battery box lifted. And I forgot to check it’s operation after the work was done. This morning I tested the 12V voltage and it looks like that I’ve either broken the DC-DC or disconnected some wire (also a very likely scenario) when I put the bike back together. The small lead-gel battery reads only 12.2 volts and the voltages do not jump back up to 13.5V as they used to do when the DC-DC worked and the bike was turned on. I’ll need to debug it this evening… Sigh.

EDIT (23pm): Just a disconnected wire. Failed crimping. Fixed…

Café Racer!

Finally had an evening to work with the bike, so that I could install the new cafe racer seat and the led flashers. And I’m loving it! I had earlier began to doubt if the new handlebar wasn’t such a good idea, as after a few days to work my back started to hurt. I wasn’t feeling that comfortable… But now with the much lower cafe seat I’m sitting much more upright again, and it feels really great. Didn’t stretch the back and neck as much. Also what’s nice is that with the new seat I can reach the ground with my both feet, heels on the ground. Didn’t like sitting as high as earlier. I might consider some day also upgrading to shorter rear shocks so that I can lower myself just a little bit more (maybe by 2-3cm). But I’m not sure if I want to mess with the driving geometry, as now the bike feels quite perfect. Honda had it “just right” the day they made this bike.

Ready to roll!

As I installed the new seat I had to create some sort of mount for the license plate. I took a bit of aluminum, cut it into shape and drilled some holes and bolted it on the small license plate holder that came with the seat. Still a bit rough, but I’ll finish it later on and I’ll paint it black. Also placed an adhesive reflector above the license plate, as our law requires to have one, even if I don’t see the point (the led tail lights are pretty bright). I’m planning on taping it below the seat, just above the license plate. Now “it’s just there”.

Kinda feels like the handling has just improved again a little bit. And not sure if this has anything to do with the mods, but this morning I made a new record low in energy consumption when getting to work, as I only used 52Wh/km even if I didn’t spare in acceleration. But I’ve lost some weight too. So maybe that really did help… The bike does feel lighter, but I think that’s mostly due to better seating position.

Took a while to figure out the wiring for the tail led lights, as they had both the tail/brake lights and turn signals integrated into one unit. They are really great quality, with solid chrome plated aluminum bodies. They weren’t cheap, but man are they pretty… Although I still need to figure out how I’ll remove the old flasher mount supports that are wrapped around the forks. I’m afraid I’ll need to remove the forks so that I can do that. That’ll have to wait until the bike is stored for winter. Then I’ll rebuild the whole instrument cluster and install new headlight mounts. Now the headlight is sitting too high, which looks a bit “goofy” to me.

Something I also did was that I wired the new handlebar on/off switch as a safety feature, which controls the power for solenoid through a relay. It will shut down the motor, but keeps everything else powered on.

PS. I know it doesn’t “do the ton” (reach 100mph), which the “true” cafe racers require from their bikes. If I switched to different sprocket ratio it could possibly reach it, at the cost of low end acceleration and energy consumption. But this bike is geared for city use, not to break speed limits. So I might never test it out. But hey, we’re in Europe. So why 100kph wouldn’t be enough? ;)

Driving Around

Last weekend was just way too busy, so I didn’t have time to install the new cafe seat and the chrome led turn signal lights, but yesterday evening I had at least a couple hours to work on the bike. I managed to fabricate a mount for the Cycle Analyst sensor magnet and to install the new handle bar with the bar end mirror. I found the wheel diameter (2082mm) and entered that to the CA setup. The magnet now works and the readings from the Cycle Analyst seem to be valid. I also installed a new handlebar on/off kill switch (previous one was glitchy and wasn’t used at all) but haven’t yet wired it. I’m going to wire it directly to the relay that is handling the solenoid control power, so the controller etc. will stay on, and this kill switch will disable only the throttle/motor.

New handlebar

Magnet mount fabrication

Magnet mount finished and installed

I raised the bar a little bit with some riser bits that I had bought so that I could get a more comfortable riding position with the new handlebar. The new handlebar is a bit more “sporty” and narrow than the original one. But I think I like how it feels now. I didn’t want to go “full cafe”, which is usually way lower. That would kill my back. This new bar makes the handling a bit more steady at higher speeds (less leverage). But it’s still nimble enough at crawling speed. I also love the new bar end mirror. It gives me a perfect vision behind me and to my left side. Way better than the originals.

But now I really want to install the new headlight mounts so that I can lower the headlight. It will give the bike a bit more aggressive look. And the old speedo cluster looks like a huge blob with the new handlebar. But that will have to wait. I think I’ll work on that during the winter when the driving season is over. I expect that in about a month it will be too cold to drive. If not sooner…

So far I’ve driven about 200km with the converted bike and everything is working real great. And today was the fourth day that I came to work with the bike. All the readings so far have told me that the energy consumption has been approx. 60-63Wh/km when I’m back home (total of 35km round trip). This morning CA told me I had used only 55Wh/km on my way to work, with an average speed of 44km/h (the speed limits are 50-80km/h and there are several lights where I need to stop). So I am more than satisfied so far. With this kind of driving (typical in the area where I live) the range of the full pack should reach about 50 kilometers. Total pack energy of 3200Wh divided by usage of less than 65Wh/km makes about 50km. Each day when I’m back home from work, I’ve used about 2000-2200Wh and about 28-30Ah. The pack voltage has leveled off just below 80 volts (a bit less than 3.2V per cell) after the 35km trip, so it would seem that there really is still a considerable amount (more than 10Ah) of juice left, as there should be.

Back Home

Got back home from the first day at work with the bike. Total consumption for today’s driving of 35 kilometers was 2086Wh (28.56Ah) according to Cycle Analyst, which makes approx. 60Wh/km. Considering it’s a mix of mostly 50-80km/h zones, I think it’s right in the ballpark where it should be. I had feared for worse, to be honest. I guess if I drove mostly 80km/h roads it would be closer to 70Wh/km. All in all, considering that I still had about 1/3rd of the pack still in reserve after day at work, I’m more than happy.

First Impressions

First impressions? Wow. I’m loving it!

The bike works real smooth and driving without a clutch or gears and with a sharp and responsive throttle and good acceleration, it’s fun as well as it is easy to drive. And handling has only improved with less weight. I really have no regrets going electric. I think I have taken one of the best bikes from the 80’s and made it a true 21st century vehicle.

During the last weekend I only took couple short trips around the neighbourhood. I was wondering why even at low speeds the bike seemed to have pretty high consumption (enough to notice). But as I went to check the tire pressures I noticed the rear wheel was near empty. Not totally flat but below 1 bar. Next spring for the next season, I’ll buy new inner & outer tires anyways. So I just filled it up and I hope it won’t empty itself too fast. And I’ll keep on monitoring the pressure. But anyways, after I had filled the tire, rolling became easier, with no real resistance and energy consumption dropped considerably. Also the acceleration feels a bit “sharper” now.

And this morning I drove it to work for the first time. This was a big thing for me, as I’ve built the bike to be my commuter vehicle. What was surprising, in a good way, is that during the 17,1km trip I only used about 940Wh (12,54Ah) according to Cycle Analyst. Which would give about 55Wh/km consumption and a 58km range, at speeds of 50-70km/h with these batteries. Interesting to see what is the total when I get back home. With our car it’s always been a bit more consuming to drive back home. (I guess in the morning I’m driving more downhill.)

Next weekend I’m hoping to have time to begin the Cafe Racer modifications. So new handle bar with a bar end mirror, smaller & prettier chrome led turning lights and the new cafe racer seat. And I really need to finally create a mount for the Cycle Analyst speed sensor magnet so that I could get proper Wh/km data from the Cycle Analyst directly.

Street Legal!

It is now official! This morning I went to inspection office (A-katsastus) to have the the bike inspected and registered as an electric motorcycle. And it passed! The bike weighted 190kg so it’s now 60kg lighter than as a gasoline bike. (It used to weight 250kg.) And while driving (or even pushing it at the parking lot) you can really feel the weight difference, especially in low speeds and when braking to stop lights.

The inspection guy went through the usuals, like the lights etc. and everything checked out. Then he looked at what had been changed in the bike and compared the ME1003 motor spec sheet to the engravings in the motor and assigned the motor nominal power to the registration sheets. Then it was only paper work. And this only paid 54 euros. Not bad.

I drove it on the highway, testing it’s acceleration and top speed, as I’ve set the controller to more power. It now accelerates very rapidly to about 90km/h and then a bit slower to 100km/h which seems to be about it’s top speed. I guess my estimations for the gear ratios was spot on, again. Can’t believe how much nicer it is now to drive as an electric. Smooth, sharp and ten times easier than it used to be. Also the sound from the chain seems to have smoothed out a bit and it ain’t seem to be as loud as it was on it’s first test drive. The sound is very comfortable (almost inaudible in crawling speeds) and I can now actually hear the other traffic (cars etc) while driving. Definitely improves my own safety. And it easily leaves all cars behind in lights, so I’m not a slug anymore with the new settings.

First Test Drive!

Today was the day I took the first test drive! And oh boy it’s so smooth to drive… Feels like a much lighter bike than it previously did (it should as it has lost quite a lot of weight), and the throttle was smooth as butter. Amps were set to only 30% of the full controller power and the “throttle up rate” was also toned down, so it ramped up amps gradually. Everything seems to work great and there was no odd behaviour. I think I can now say with confidence that the conversion was a success! Next up: inspection… After that: “beauty pass”.

Batteries in Place

The batteries are now in place and everything works! The battery case structure seems really sturdy and I think it’ll do great. Only because it was in the middle of the night (literally) and I was dead tired, I decided against taking a small test drive with the bike. I really need to go through everything I’ve done (tighten any loose bolts and zip-tie wires etc) in daylight and figure out some sort of proper mounting for the DC-DC converter (which in the picture sits on top of the bike for the time being). With the batteries in place the converter doesn’t fit anymore below the gas tank. There’s enough room behind the upper box but I need to mount it there somehow. I might drill some holes to upper battery box (batteries removed) so that I can mount it on it’s side. I’m thinking of drilling the sloped corner areas in the top box as there’s room for bolt ends inside and I can first bolt some sort of a mounting plate there where I can bolt the converter on to. But in the long run I might actually consider a more expensive but a lot smaller converter to replace this bulky chinese one…

Battery Boxes

Finally! This saturday I took my bike on a trailer to the welder so that we could make the battery box connection tabs that can be attached to the frame. We didn’t have time to finish the boxes on saturday, but yesterday I got the finished boxes. They are both made from pretty thick (4mm) aluminum sheet and seem to be a really tough construction. (They look like they could withstand a nuclear war.) The lower box will be bolted to the original engine mounting points with 10mm threaded rods and the upper box is bolted to the lower box with 10mm bolts. The lower box also has a tab that is bolted to the motor adapter plate. This is mainly to support the motor plate to the boxes (not the other way around) and should make sure that the motor mount is stable. There are also some additional tabs on the upper box that will be used to mount the fiberglass fairings (still to be done) to cover these clunky things from prying eyes. And the upper box will have a fiberglass cover that will be latched on top of it.

Welded Battery Boxes

Primed Lower Box

Glossy Black Paint Layered

Late yesterday evening I drilled some holes to act as cable conduits and cut them open upwards. Then I used steel wool to roughen all the surfaces for painting, washed them dust-free and then layered the black primer paint in several passes. This morning I went to see how they were, and as they looked really great, I layered the final glossy black paint on top of the primer.  And this evening I will cut an adhesive rubber mat that will isolate the lower compartment battery poles from touching the upper box and will make sure there won’t be any kind of possibilities for any other unwanted “special effects”.

I’m hoping the boxes will be dry enough this evening so that I can finally start placing the batteries inside the bike. And maybe even take a first test drive! (We’ll see.)

Soon…

Yesterday I finished up some final cleanup and tried to figure out why the 12V battery had drained dead while the bike had sat there for couple of days. I suspect the DC-DC as everything else is key-switched (the converter has key signal switch too and should be shut down, but who knows)… I’ve now isolated even the 12V negative side from the DC-DC with a relay when the bike is shut down. And I’ve also added a physical battery cut-off switch for the 12V system, at least until I can be sure there’s nothing there draining the battery, when everything should be shut down.

I also got the aluminum battery boxes and test fitted them in the frame. Tomorrow I’ll transport the bike to the welder so we can create the attachment tabs so that they can be bolted down. They’re welded from 4mm aluminum so they should be pretty bomb-proof. Hoping to be able to make some test driving tomorrow… We’ll see.

And today I called to the inspection office and talked with the technician about the inspection. Hopefully this will be pretty straight-forward and the bike will become street legal (if nothing profound needs to be corrected). Then the real fun begins…