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

Road Testing

The bike is now in the city and completely legal, so it's time for road testing.

I'm anxious to find out some stats.

Sitting still, the PakTrakr reports a draw of .2 amps.

With the LED Truck-Lite on low-beam, it shows .4 amps.

High-beam makes it .6 amps.

A quick spin around the neighborhood showed 94+ amps on acceleration but only 29 amps for steady cruising.

It's seriously fun to ride.

It is almost like floating down the road. It's pretty quiet of course, but there is a nice electrical whirring created by the motor at 25 mph. I may need a different drive sprocket to achieve 55 mph. The mirrors may need to be relocated or replaced for safety. The license plate may need to be relocated for preference. Overall though, it's a really cool way to get around.

Pictures and stats to come soon!

-Colby

Sevcon DC Converter

A Small Problem:

My bike has a 12 volt electric system for the lights, gauge cluster and horn. I used a 72V to 12V DC converter to supply power to that 12 volts system. I chose the Sevcon 300W converter and ordered it from ElectricMotorsport.com. My only complaint is that I was not provided a connector or a specifications sheet for the device.

The Solution:

Well, the spec sheet .pdf is easy to find at the manufacturer's website:

• Manufacturer Site
• Specification Sheet

The plug was not as easy to find, but I gathered enough clues until I nailed it down. The converter connector is a Mini-Fit, Sr. housing, made by Molex. There are technically three different kinds of housings, but there is only one receptacle that fits all three, so you can place an order with confidence. The only catch is that it may not come with the actual conductive terminals - depends on where you order it from. Luckily, I knew my would not come with terminals, and I was able to find them too.

• Manufacturer's Mini-Fit Sr. Site

Part Numbers:

I ordered my plug and terminals from Allied Electronics in Fort Worth.

The Molex part number for a plug is 42816. (need 1)

The Molex part number for a female terminal is 42815. (need 4)

The Allied Electronics part number for a plug is 863-1427.

The Allied Electronics part number for a female terminal is 863-1464.

Additional Info.:

Be aware, if you order from somewhere else, there is an entire series/family of Mini-Fit connectors which include single-row / dual-row and 2 through 8 circuit variations. Also, there is a clip which is molded onto single-row connectors which serves to stop the terminals from backing out. For the record, the receptacle I needed for the converter was a single row, 4 circuit connector. Since it didn't include terminals, I ordered 4 terminals for size 14 or 16 AWG wire. The whole thing goes together really easily and makes a reliable connection to the converter, which was great to see.

Here's the search string to find all members of the series in Allied Electronics' online interface.

http://www.alliedelec.com/search/searchresults.aspx?N=0&Ntk=Primary&Ntt=Mini-Fit+Sr.

Here's a .pdf which explains the parts with images, in case that helps clear up any confusion.

http://www.molex.com/molex/products/family?key=minifit_sr&channel=products&chanName=family&pageTitle=Introduction&parentKey=minifit_products

-Colby

First Test Drive

The bike was finally at a point we could test drive it this weekend, so that's exactly what we did.
It rode pretty smooth, very quiet, and everything went just great.

Check it out:

Several things remain, but registration and inspection are very near.

-Colby

Controller Grounding

After wiring up the controller, we found that the chassis was being grounded somewhere. We weren't sure if this was normal or not or good or not so I researched it.

Kelly User Manuals:

Version 2.3 of the Kelly user manual specifically mentions not connecting B- to GND on pages 10 and 11 (sideways footnote), but in this instance, I believe they are referring to the GND pin on the front and rear panels which is simply a ground connection for input and output sensors. So this doesn't answer my question. However, version 3.1 of the Kelly user manual specifically mentions it being preferable to wire B- to the chassis on page 9.

The Forums:

I signed up for ElMoto.net recently and today I was in the chat room when a couple guys joined: RC and Guff. We got to talking about my bike and I asked about this issue. Each said their bike has neither the low-voltage system (12 volts) nor the high-voltage system (72 volts in my case) grounded to the chassis. When I asked about how to accomplish that with respect to the high-voltage components, at least two solutions were mentioned. I guessed that plastic screws / washers were required, because that's what Lennon did. However, RC mentioned using polycarbonate board, which serves as an insulator. Without using special hardware, a component can be mounted to a sheet of polycarbonate or something like "garolite" and the sheet then mounted to the chassis. This isolates the two, so even if the component isn't internally isolated from its outer casing that won't leak on the bike chassis. For the low-voltage components, I've read posts about running new ground wires to the lights and horn instead of using the chassis.

After chatting with them a while, I searched more and found these threads agreeing with their input

• ElMoto.net, Thread 1039 - Grounding the chassis
• ElMoto.net, Thread 1527 - Main fuses, internal Kelly grounding
  

Additional threads:

• ElMoto.net, Thread 2167 - Main high-voltage components / grounding
  
• DIY Electric Car, Thread 14817 - Kelly KDH14500 wiring / grounding
  
• V is for Voltage, Thread 4066 - Kelly refund & exchange policies / testimonials
  

That last thread mentions something interesting: The author of post #5 in states that High-voltage Kelly controllers are not insulated from the chassis ground while low-voltage controllers are insulated from the chassis ground. That might have been the case in July of 2008, but I'm not sure it is still reliable information, and I don't know which controllers he's considering high or low-voltage.

The issue:
Safety is the main deciding factor here. If the bike chassis is grounded to the pack, then (depending on exactly what you touch) you could complete a circuit with your body or with a tool and damage yourself and your bike. I don't feel great about ignoring what the controller manual says, but I'd rather the bike be safe to work on than dangerous because of what could be a poor translation in the manual.

For the record:

Strangely, while researching, I stumbled upon a thread about using a Kelly controller in some Z20 model scooter, and then a completely separate thread referencing the first, concerning (rather questioning) Kelly, their product and their service.

1. V is for Voltage, Thread 3714 - Moving to a Kelly controller for Z20b
2. DIY Electric Car, Thread 16961 - Kelly controller quality

I guess the guy whom started that thread on DIY was in a hurry or failed to notice the picture was not of a Kelly manufactured model, but of some controller being provided for electric scooters by some dealer. Anyway, for the record, I've had no problem with Kelly, nor with my Kelly controller (it's been in use for one week). While chatting on ElMoto.net, one member mentioned his Kelly controller has been working just fine for 6 months. My only complaint is about the lack of clarity within Kelly's manual and wiin replies to questions via email. I've emailed sales@kellycontroller.com a couple times regarding both sales and technical wiring support and have always received quick responses. If you can be patient and don't mind reading and thinking a bit, I imagine Kelly will do right by you. If you do email them, use direct and very clear language to ask individual questions. That's what has worked for me. I haven't read about any instances of faulty Kelly controllers, though you do have to seriously study the user manual provided. Even in cases where a controller gets cooked because of user error, it seems they often replace the controller or offer to repair it, usually only for the cost of shipping.

On another side note, ElMoto.net has been a great resource so far. The users seem down to earth and willing to help newbies like myself. There's a lot to figure out, and it seems every bike is slightly different. Starting a thread for my project has helped quite a bit already.

-Colby

Rotation

It was a big day for the bike.

The motor turned for the first time today.

I've been making good progress at figuring out wiring details in the past weeks and we finally got to a point where we could pretty safely test the contactor, controller, motor and throttle. It seems to work, which is really exciting. The controller was programmed to greatly limit is output and after minor troubleshooting, the controller's LED showed it was ready and without errors. It's a bit jerry-rigged at the moment, but we'll be making more permanent connections soon in order to do test runs and get it inspected.

Here are a couple pictures of the controller. Like I said, jerry-rigged for testing!

Rear Panel:

Front Panel:

-Colby