Terminals

It's rainy today, so I've replaced the ring-tongue terminals on the charging leads (DC side). They were 1/4" and now they're 5/8" to match the batteries.

I originally tried drilling out the 1/4" terminals, which worked alright at first, but turned out to be difficult and dangerous with my tools. After destroying one in the process, I decided to replace them altogether. The fuse holder on the positive lead is closer to the terminal now, but that shouldn't cause any problems.

Next step will be to re-install the batteries on the bike with these leads attached.

Happy New Year,
-Colby

Holiday

It's been a while since I posted any picture of the bike. Here is what it looks like at the moment:

The tail-light assembly and license plate bracket are missing from that picture. I got to looking at the rear section the other night and realized how big and ugly it was. Also, I often clipped the license plate bracket with my leg while getting on and off. I found a nifty DOT approved LED Stop/Turn/Tail (STT) light for the back. I'll be using it only for the brake-light and tail-light, though, so I'll need to order some more arrow-head turn signals to go in the back. Here is the new tail light next to the old assembly.

The tricky part will be making a little housing for mounting the new LED brake light and turn signals. I 'll probably try using plastic first. I'm sure fiber-glass would work too, but the weather may not allow it to cure in a timely fashion.

Here is the tank, powder-coated to match the wheels:

 To give you an idea of the final product, here's a picture of everything staged together:

I'll be off work until the new year so I'm hoping to make some progress during the break.
-Colby

More Labeling

This weekend, I touched up the new black paint and added labels to the batteries and their charging leads. I'm looking forward to how much easier assembly will be with clearly identified wires and plugs.

To do list:

• Shorten D.C. charging leads
• Combine A.C. changing leads
• Label chargers with a battery number
• Make the gas tank fit again

-Colby

Cable Labels

I've been meaning to label the main battery cables for a long time. I finally got around to it this evening. I found an acceptable font, printed out a sheet and used some Scotch heavy duty clear packing tape. It's nothing special, but it is simple, cheap, easy and functional.

The 1 inch rubber hose pieces at the ends of the cables are just temporary safety precautions used when installing or removing batteries and their connections. There is not a lot of space to maneuver the cables, tools and mounting hardware once the battery is in place on the chassis, so better safe than sorry.

I'm waiting for the weekend to take a shot at another coat on the chassis and/or re-assembly. I'll use the new charging leads when I put everything back. Then, I'll work on exactly how and where I'm going to mount the chargers. I'll also need to shorten all six charging leads to the battery by 3 feet and combine all six A/C plugs into the single 110 volt extension cord.

No big, I guess.
-Colby

2012 Summary

I haven't updated anyone about the bike in a very long time. I'd like to do so, briefly. The two main things I'd like to document are some recent aesthetic enhancements and a new charging system.

My motivation for some of these changes is related to an upcoming opportunity for displaying the bike. My employer will likely be hosting a grand opening for our new office in early 2013. This office has just been constructed and incorporates many energy efficient and environment friendly features. One such feature is the electric vehicle charging station. I think I'm the only employee with a battery-electric vehicle, so I'm hoping to make good use of the parking spot and convenient charging. I'd be proud to have the bike present at the grand opening and I'd like it to look its best.

Since I posted a picture of the bike last, I've had the wheels and gas tank powder-coated white. I've also touched up some of the chassis in black. Those are the new primary colors. The tank seems to have changed shape a bit due to the powder coating process (it has no bottom and I suspect the curing oven caused the change). I'll have to make some adjustments and do some re-assembly before posting an updated picture.

The charging system is being swapped out while the bike is partially torn down for painting. The two 36 volt chargers originally installed worked alright over the past few years. However, I feel I have learned part of the answer to a question I had when originally trying to understand and purchase chargers. That question was, "Does it matter whether I go for many individual chargers, one huge charger, or slice the battery-pack into multiple, smaller battery banks?" I eventually decided to slice my six battery pack into two banks of three and purchase two 36 volt chargers. In principle, it adds up just fine. In practice, the primary issues with that approach is how unbalanced the pack can become.

The pack becoming unbalanced over time seems unavoidable now. As an example, I think my PakTrakr taps the first battery alone, which I now consider poor design. I hope they have changed it since then or that I am somehow mistaken about it only drawing from the first battery. Even that tiny draw (in my situation) just further unbalanced the first battery from the rest of the pack. I installed a small on/off switch for my PakTrakr and the first battery was immediately more in-line with the others.

I'm moving to six individual chargers. I'm sure I could have gone the other way and moved toward a single charger as part of a battery management system, which may just be a fancy (and justified) version of using individual chargers. However, that seems like good territory for a second build given the expense and research required. In the mean time, using individual chargers is a pretty cost effective and simple solution for the bike and should give me optimal charging.

I'm hoping to use the bike for routine commuting in the new year, in line with its original purpose. Despite the winter season, I hope to have it looking and running well soon.
-Colby

Riding, Instruments, & Batteries

School is occupying most of my time, but I've worked in plenty of motorcycling and a lot has occurred in the last month.

The thing is a joy to ride. I know I already tried to describe the sound, but it's such a cool whirring noise. "Idling" at stop lights is completely silent and really makes it stand out when somebody knows better. It's a real attention-getter in general too, because even though people may not recognize it as being electric, they know something is missing, or changed, or totally different about it. Makes for an easy conversation starter, really. As you can see below, I've put 120 km on it so far, which is 74 miles.

Hardware:
I had a few mechanical issues early on. The rear hub is attached to the rear sprocket with four bolts. The nuts are captured in the hub. When I originally tore the rear hob down, I had to fight two bolt-head-locking washers. Each washers secures a pair of adjacent bolts by going on before the sprocket (acting as a washer of sorts) and then being force-formed around the head of the bolts (acting as a bolt-head-lock) to keep them from turning. Long story short, I completely forgot about them in re-assembly and they most definitely serve a purpose. I lost several bolts out of the hub (banging up the swing-arm, the hub, and the sprocket in the process) and unknowingly, barely made it home once or twice. What a mess - I felt stupid.

Gearing:
Meanwhile, I was also finding out that my gear ratio was not going to suffice. The rear sprocket was kind of a random find, so we just went with it because it was easy to make it work. A little measuring, welding, and painting and suddenly, it was ready. We either forgot to adjust the desired number of teeth for the front sprocket, or again went with what was readily available locally. At the time the bike was licensed for use, the rear was a 68-tooth and the front, a 12-tooth. That's a ratio of 5.667:1. That's pretty steep. Having very little experience on any kind of motorcycle, I was still impressed with it's power and ability, but as I tested the top speed, it became obvious this ratio wouldn't meet my long-term requirements. The top speed was 43 mph. The way to work is 45 mph, which means traffic goes 50 mph, so my first ride to work was a bit scary. The trip was a success, but it sealed the deal. I did some calculations and asked a few experts online. We didn't look for a new rear sprocket - I kind of assumed it be hard to find and make work but perhaps not. We went local again and got a 17-tooth front sprocket instead. What a jump! Now the ratio would be 4:1. That's exactly the ratio Juiced from ElMoto suggested for street bikes - as opposed to 3.5:1 for his drag bikes. This new sprocket's arrival coincided with that of the replacement hub, so I changed out both at once, lengthened the chain by four links and I feel great about it. The new hub not only had nuts which fit better, but it came with a new bearing already installed and it was so much smoother than the original. I bought some removable Loctite for the hub bolts and I installed the bolt-head-locking washers with the proper tools for a super snug rear-end. The result was just what both I and my dad calculated. The top speed is now 56 mph. This is perfect for my current and future work commute (we're moving, eventually).

PakTrakr
The PakTrakr has been really useful for gathering all kinds of information: amperage, battery voltages, kW usage, etc. Unfortunately, it's not working quite as smoothly as I had hoped. It could be user error, but I've had problems with the following:

• Battery voltage gauge indicates almost empty while batteries are nearly full.
• The LCD screen has blanked out while under medium to heavy acceleration.
• The entire module has reset while under heavy acceleration.

In the PakTrakr manual, it does state the batteries must be fully charged before plugging in the PakTrakr. The battery gauge showing empty instead of full could therefore be my fault, as I'm not totally sure what "fully charged" is for my system. A 12-volt AGM battery can apparently hold around 12.8 volts under normal conditions, so six of those make for 76.8 volts. However, since it reset on me mid-ride the other day, it now thinks my whole system is overcharged. =/ I do and have had the module set to AGM batteries, so I know it's not the case that it thinks the batteries are flooded or some other chemistry. I guess I'll have to email the manufacturer or post on the forums to figure out what is going on.

Amps
The amperage on the battery side of the controller has, of course, changed along with the gearing changes. At 5.667:1, I could slowly accelerate up to 25 or 30 mph without breaking 15 amps. At 4:1, I'm immediately at 30 amps or so and it's difficult to cruise at any speed while drawing less than 25 amps. Under hard acceleration, I used to pull maybe 110 amps at the most. With the new ratio, I got a reading of 150 amps. Keep in mind, that this is on the battery side. The motor is rated for a continuous 125 amps with bursts of up to 300 amps for no more than 30 seconds or so. The reduction in leverage is very apparent, both in these values and in the physical feel and pull of the bike. For my use though, it's worth having the top speed where it is now, instead of all that acceleration. I plan on trying to take care of this batch of batteries as much as possible, anyway.

Watts
I finally got a chance to gather a couple readings of kW usage as well. I never checked this with the original gearing, but the new setup resulted in 3.5 kW at around 25 or 30 mph and 5.4 kW at a steady 50 mph on level road.

3.5 kW / 30 mph = 3.5 kWh / 30 miles = .11667 kWh/mile = 116 Wh/mile = 72.5 Wh/km
Similarly, 5.4 kW at 50 mph is 108 Wh/mile = 67.5 Wh/km
I am not positive whether or not these calculations are correct, but they do seem reasonably close to that of other bikes of similar design.

Battery charging and discharging:
Below is the log that I've kept on battery charging discharging. This may or may not be terribly useful just yet, but in case any of the batteries don't last like the others, I'll be able to see if it was destined to or if I did something wrong.

SC = Start of Charge
EC = End of Charge
SR = Start of Ride
ER = End of Ride
BC = Battery Check

Act.	Y	M	D	h	m	B1	B2	B3	B4	B5	B6		Pack		State	Odom	Ratio
SC	10	8	19	22	17	11.5	11.7	11.6	11.7	11.8	11.8		70.1			39.2	5.7:1
EC													76.7			39.2
SR													76.8		resting	39.5
ER	10	8	22	19	00	11.7	12.0	11.9	11.8	11.9	11.9		71.3			68.5
SC	10	8	23	21	00											68.5
EC	10	8	23	23	30	12.4	12.6	12.5	12.4	12.5	12.5		74.9		resting	68.5
SC	10	8	24	20	40	12.2	12.5	12.4	12.3	12.4	12.4		74.2		resting	68.6
EC	10	8	24	21	40	13.0	13.3	13.2	13.0	13.1	13.2		78.8		charging	68.6
EC	10	8	24	22	25	12.5	12.8	12.6	12.5	12.6	12.7		75.6		resting	68.6
SR	10	8	25	19	45	12.4	12.6	12.5	12.4	12.5	12.6		75.0		resting	68.7
ER	10	8	26	01	00	12.0	12.3	12.2	12.1	12.2	12.2		72.9		resting	80.6
SC	10	8	26	18	35	12.0	12.3	12.2	12.1	12.2	12.2		72.9		resting	80.6
EC	10	8	26	21	15								84.4		charging	80.6
EC	10	8	26	23	05	12.6	12.9	12.8	12.7	12.7	12.8		76.5		resting	80.6
SR	10	8	27	07	40										resting	80.6
ER	10	8	28	00	05	12.1	12.4	12.3	12.2	12.3	12.3		73.6		resting	91.1
SC	10	8	29	20	13											91.1
EC	10	8	29	22	00	13.1	15.7	15.2	13.2	13.4	13.5		84.1		charging	91.1
EC	10	8	29	22	50	12.5	12.9	12.7	12.6	12.7	12.8		76.2		resting	91.1
SR	10	9	18	00	28	11.8	12.5	12.4	12.3	12.4	12.4		73.7		resting	91.2	4.0:1
ER	10	9	18	01	25	11.5	12.2	12.1	12.0	12.1	12.2		72.1		resting	100.5
SC	10	9	18	13	55	11.5	12.2	12.1	12.0	12.1	12.2		72.1		resting	100.5
EC	10	9	18	16	10	12.3	12.2	12.1	12.0	12.1	12.2		72.9		chrg B1	100.5
EC	10	9	18	16	50	12.0	12.2	12.1	12.0	12.1	12.2		72.6		resting	100.5
SC	10	9	18	17	00	12.0	12.2	12.1	12.0	12.1	12.2		72.2		resting	100.5
EC	10	9	18	19	00	13.0	13.3	13.2	13.0	13.1	13.3		78.9		charging	100.5
SR	10	9	18	19	15	12.5	12.7	12.6	12.5	12.7	12.7		75.6		resting	100.5
ER	10	9	18	19	47	12.2	12.5	12.4	12.3	12.3	12.4		74.0		resting	105.2
SR	10	9	20	17	50	12.1	12.4	12.3	12.2	12.3	12.4		73.7		resting	105.2
ER	10	9	20	19	00	11.9	12.3	12.2	12.0	12.2	12.2		72.7		resting	110.1
SC	10	9	20	20	00											110.1
EC	10	9	20	22	00	13.0	14.6	13.6	13.1	13.6	13.6		81.2		charging	110.1
EC	10	9	20	23	00	12.4	12.7	12.6	12.5	12.7	12.7		75.5		resting	110.1
SC	10	9	22	17	40	12.2	12.6	12.5	12.4	12.6	12.6		74.9		resting	110.1
EC	10	9	22	18	40	12.9	12.6	12.5	12.4	12.6	12.6		75.6		chrg B1	110.1
SR	10	9	22	19	05	12.5	12.6	12.5	12.4	12.6	12.6		75.0		resting	110.1
ER	10	9	22	20	47	11.9	12.2	12.1	12.0	12.2	12.2		72.5		resting	121.4
ER	10	9	22	23	10	11.9	12.2	12.1	12.0	12.2	12.2		72.6		resting	121.4
BC	10	9	23	17	45	11.9	12.2	12.1	12.0	12.2	12.2		72.6		resting	121.4
SC	10	9	23	17	50	11.9	12.2	12.1	12.0	12.2	12.2		72.6		resting	121.4
EC	10	9	23	23	00	12.8	12.2	12.1	12.0	12.2	12.2		73.5		chrg B1	121.4
EC	10	9	24	00	05	12.3	12.2	12.1	12.0	12.1	12.2		72.9		resting	121.4

I'm still learning plenty about the batteries and my chargers. The chargers are supposed to be intelligent enough to do a 3-stage charge and turn their LEDs green when in the float-stage. This has never happened and makes me worry about A) the chargers being wired and used in a manner for which they were not engineered or B) the two large sparks upon finally assembly having screwed them up. I guess option C would be that I've never absolutely fully charged the battery pack halves. This would actually be good news I think. What's strange is that the PakTrakr shows some batteries slowly being charged up to 12.9 volts, while others batteries show to be charging up to 14 volts and higher, and accelerating upward in charge voltage. For example, look at August 29th, during charging (EC.10.08.29.22.00). Here, batteries 2 and 3 were very far above 13 volts, which was scary and I have no idea if this is dangerous or normal. Maybe they would eventually get float-charged by their charger, once B1 matched them.

Balancing:
Balancing the pack is also a new adventure. I purchased a 12 volt battery charger from Walmart which stated it was compatible with AGM type batteries. So far, batteries 1 and 4 have turned out to rest just a bit lower than the others. Attempts to bring B1 up with the likes of B5 and B6 haven't exactly been successful just yet. However, I haven't let this charger, like the other on-board chargers, reach what it considers fully-charged. I still need to learn how sensitive the batteries really are and whether I'm hurting them in any way. Once again, this will take research and assistance from the forums probably.

Other Notes:
I accidentally got caught in the rain the other evening - No failures of any kind, but how much water can the ME709 really take in those vents?

Inspecting the bike has been more critical than I expected. Had I inspected it closer from day one before each ride, I would have avoided several headaches and delays. Far too many close calls in this area.

Also, for the record, I would like to say how much I enjoy the correctness of the term "motor-cycle". Naturally, I never thought of it as inaccurate before stumbling into the EV scene, but how cool is it that my bike really is a motor cycle, not an engine cycle.

-Colby

First Impressions

I rode the bike around my neighborhood all evening yesterday. The odometer and speedometer are primarily in kilometers, so I'm still deciding what unit of measurement to work in. I'd like to keep a pretty close log of rides and data to try and track the health of the system for a few months.

Ride 1	Start	Stop	Max
Odometer (km)	12	37
Voltage	76	69
Batt. Amps			100?
Speed (mph)			40

25 km is 15.5 miles, so I'm really happy about the range so far, even if I averaged only 20 or 25 mph. It's certainly no worse than my worst-case scenario. It will interesting to see what range I can get at an average speed of 40 or 50 mph though.

I tried to keep an eye on the PakTrakr:

I could easily accelerate and keep the battery-side amperage at or under 10 amps.

I could maintain 25 mph at about 4 amps.

The PakTrakr seems a bit confused about my battery State of Charge (SoC) at the moment. I followed the instructions and changed the chemistry setting to AGM, which I know to be accurate. Still although it can accurately report the pack voltage, it shows the SoC as being 72% when the pack is at 77 volts. The fuel gauge mode shows a mostly empty tank even though the pack is still around 71 volts. It could be user error - I've reset the display by unplugging the remote several times. As far as I know, everything else is working fine. I love the thing already, but I need to try and correct the issue.

My chargers are not working like I expected either. I'm not sure why, but they don't seem to shut-off, or rather, go into float mode when I think they should. Then again, I'm still a bit unsure what voltage my pack should have when "fully charged". If a fully charged AGM 12 volt battery actually reads 12.8 or 12.9 volts, then my batteries are spot on. The charges just seem to stay on full-blast (and stay hot), even once the pack has reach 77 volts (according to the PakTrakr). It might be that the two, 36 volt chargers are wired in series practically, and so they're interfering with each other's monitoring logic. I guess I could try charging the pack in halves to see if their behavior changes.

The controller only threw one error message while I was actually out riding. This too was probably my fault. After coming to a stop, I went to make a sharp right, which led to a down slope. There was a chug-a-chug feeling that may be mechanical on the bike between the motor, chain, wheel and swing-arm. I felt for a moment that the bike was trying to go sporadically, although not with full-power like a run-away. Somewhere in the chugs and whatever strange throttle inputs I gave it, the controller detected a problem. I only wish I had written the error code down, in case it occurs again or was something I haven't seen yet. A simple re-boot allowed me to keep going. I checked for damage or heat but found nothing. That was mid-way through the ride and it didn't hiccup, so to speak, any more.

In the end, it was super cool cruising around and turning some heads last night. Next thing to do is solve the few remaining mysteries and start people-proofing it so I can leave it in public with confidence.

-Colby