eVFR 2.0: 72V 20Ah test pack

During the upgrade to Lithium, I started working with a friend of mine, Eric Cha. Eric and a couple other his colleagues are working on a 3-wheeled commuter vehicle. He aproached me last year and I started helping him with the electrical system. In the end, we ended up with the same DeltaQ, Headway, Elithion, Vicor, Curtis and Hi Performance Golf Cars system.

He also happens to be an iPhone developer. We started talking and both realized we wanted some sort of integrated display. We started looking at some hardware we could use to talk to the controller and BMS and settled on a design. We have the hardware that can talk to the iPhone in our hands, and he’s got some code started. He has released details about the product on his website.  

In order to begin on the iPhone display project, we had to get a pack with BMS running so we could start talking to it. We bought the crimper and connectors and assembled the 72V 20Ah pack  and installed the elithion BMS system. We plugged it in, wired up power and plugged it in. It immediately came up on the computer screen using a terminal program.

Here are some pictures of the 72V 20Ah test pack:

So now that the pack has been built, and the elithion system is communicating, Eric has started working more on the coding for the iPhone. He got the hardware talking to his computer the other night. Our intention is to integrate the BMS and Curtis Controller to the iPhone via their serial connections and a Wifi connection to the iPhone. The gauges will be very customizable depending on the users needs. After we get the initial development done, we’ll start to add features and other device support.

The BMS we’re using reports back the State of Charge, the voltages of all of the cells, current coming out (going into) the battery pack, the temperature of each cell board and status of the system components. The Curtis controller has a Speedometer output, Battery Discharge Indicator, Battery Amps, Battery Pack Voltage, Motor RPM and Motor temperature. We’ll be using the BMS for Voltage and Amperage measurements and the Controller for Temperature and RPM related information.

Other updates:

• Motor Mount/endplates were delayed a couple weeks.
• My 192 Headway cells had to be sold and my replacements have arrived at EVComponents. I will be picking them up this weekend.
• I got a Pelican iPhone enclosure that is waterproof and allows viewing of the phone inside the case. I’ll attach it to the gauge area on my bike and replace the gauges on the bike.

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Racing news: OMRRA adds Electric Motorcycle division

I just got this in an email today from someone. OMRRA is adding an Electric Motorcycle division at PIR here in Portland, Oregon. Its about a 20 minute drive from where I live. I’ll definitely be making my way out to some of these events.

Press Release, March 2, 2010

The Oregon Motorcycle Road Racing Association to hold races for electric motorcycles at Portland International Raceway. Due to the increased interest and availability of battery powered motorcycles, OMRRA has recently included an electric motorcycle class in all 6 events on the 2010 calendar at Portland International Raceway.

Race dates are:

• 5/22-5/23
• 6/26-6/27
• 7/24-7/25
• 8/21-8/22
• 9/25-9/26
• 10/23-10/24

Track entry is $10 at the gate. Children 12 and under are free. Military in uniform are free. See www.OMRRA.com for rules, information, and printable $2.00 coupons. Contact OMRRA at 503-221-1487 for more information.

What is OMRRA? For over three decades, the Oregon Motorcycle Road Racing Association has run safe, exciting, and competitive events for motorcycle road racers and their fans. Racers range from club level to professionals with national and international experience. OMRRA operates at Portland International Raceway, a city park and world class racetrack.

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V2.0: Inside the AC15 motor

So I talked with my motor mount fabricator the other day, and we looked over the AC15 motor a little. It appears that the motor is quite a bit longer than it needs to be. He asked me to take apart (which I wanted to do anyway), so that we could see if things could be integrated more. We want to do some drawings of the main part of the motor and see how a motor mount/bearing holder could be built. Not sure if we’re doing it just yet, but it helps to have it apart to see how feasible it is. From first glance, it looks like there may be some room for a couple lengths of copper tube for cooling. Here are some pictures of the motor disassembly:

So hopefully this week I’ll have a better idea how the motor is going to be mounted. In the meantime, I can at least plan for the motor to be in a specific spot on the frame. I’m going to try and mock-up some battery stuff.

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V2.0: Mechanical planning

So, I was out of town for about 2 weeks for Christmas. I got to see family, some friends and my girlfriend’s friends….. in NJ, Virginia and DC. It was tons of fun, but I’m kinda glad I’m back. I should have more time available to do some stuff on the bike.

Last week, I decided to go ahead and throw a small pack together with the BMS boards installed and take some pictures. I need to get an idea on how much room I need. I used one positive, one negative and one mid board. There are 3 physical connections to the actual batteries per-board. Each board balances 2 cells. There is also a communication connection between boards (1-wire), and on each negative and positive board, it goes back to the  controller. I need to order connectors and see if I can get some communication working the next few weeks, but the BMS will be one of the last things to setup, I’m more worried about getting things put into the bike. Here are some pictures of a 6s2p pack with BMS installed:

I went to Home Depot this last weekend and got some Pink insulation foam. Its about 1.5″ thick and pretty sturdy material. I plan on cutting pieces of foam to mockup the space inside that I can use for batteries and controller. I’m getting to the point where I can start to really get a good idea on how I want to mount things.

Last night a friend came over and we went over the chassis. It sounds like he’s going to help me out with the motor mounting, and maybe a cooling plate for the controller. I’m going to disassemble the motor so we can look at it to see if there’s any way to reduce the motor length and mass. We need to see how it mounts to the end plates so we can figure out a way to mount the motor efficiently inside the frame. I also realized, that the chain position was wrong, and the motor could shift down and back about an inch, which would put it closer to the pivot point. That gives me another inch for batteries, which I’ll need. I wanted to shift the batteries backwards anyway.

Motor mount will be aluminum. Battery case might have an aluminum frame for mounting strength, but the sides will likely be hard plastic, so things don’t rub and short. I saw a 192-cell pack of headways sitting on a bench on Tuesday. It was about 22″ tall, 10″ wide and 12″ deep. Huge copper busbar (which I will implement as well) really made the pack rugged. The funny thing, I have 10.5″ wide, 13″ deep, and 22+ inches tall, so I think I can actually fit my 192 in my bike without much modification.

So, agenda:

• Dissasemble motor and take pictures and measurements for the motor mount
• Get mockups of controller, motor and charger and decide on placement
• Use foam to fill the empty space where batteries will be installed
• Use the mockup of empty space to design a mattery pack
• Fabricate motor mount and battery case

This should get me to a point where I can assemble the bike and get the main system working to test. Then I can move forward on getting the 12V system working, as well as make sure the keyswitch, contactor, kill switch all function the way I want them to. Finishing the bodywork, headlight mounting and dashboard will all come last.

Its taken a while, but its really starting to come together. Its my first time really doing any sort of mechanical design, but I’m having fun learning. It’l pay off in the end.

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V2.0: Batteries and BMS

Its been a busy season. I went to Ashland, OR to visit Brammo and Barefootmotors (will write about that this weekend hopefully). The weekend after that I went to Spokane, WA for Thanksgiving with my relatives. I haven’t had a ton of time to sit and do stuff on the battery side of things.

Last night, I brought my batteries inside from the garage. The temperatures have been very low this last week, and I feared the batteries might get damaged. I sat down for about an hour and measured each and every battery. Out of 195 batteries that I had sitting there (6 more are at Synkromotive, 1 in my car), one was 2.8V, two were 3.19V and 2 were 3.22V. The rest were between 3.28V and 3.33V. Not bad for sitting almost 3 months.

So my plan this weekend is to make some progress with the batteries. I want to put small batches in parallel to equalize, and bring them all up to ~3.65V with a 3.7V DC-DC converter and power supply I’ve got. After letting them charge, I’ll disconnect and let them all balance between eachother and settle. This will ensure a balanced pack before building. If it isn’t pre-balanced, the BMS will take a long time to balance the cells by itself. People often make the mistake of not balancing the pack before assembly, which can cause them many problems down the road.

Hopefully I can finish equalizing cells this weekend. If I do, I’m going to see if I can borrow a CBA-II from Phil Hochstetler (to do a 3-4C discharge on each cell to make sure they’re all in good shape for the pack. I can log each battery and save the graphs. It’l help knowing how each battery (barcoded) progresses over time.

I don’t know if I’ll have time to get much more done before I go visit family in Roanoke, VA for Christmas. I leave the 24th of December and return the 4th of January. Once I get back, I need to contact my welder to get the fabrication started while I do some battery setup and test.

Thats it for now. Should be a fun January and February now that I’ve got pretty much everything.

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TTXGP: Race at Infineon in May

I read about the release of the Mavizen TTX02 motorcycle last week. I had known about the project for a while and had eagerly awaited its release at SEMA. Really slick looking bike based on the RC8. After reading a little about the bike, I saw a few other blogs that mentioned something very very interesting…… TTXGP in the US at Infineon.

I looked online, and its about 9 hours from here. I got to thinking, I should go…. and bring my bike. I just need to find more details on the race. Even if I don’t race it, I’m bringing the bike.

Its an exciting time, we’ll see where it goes!

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