x88x EV saga, v1.0: Honda E15 Magna

[x88x]

Well, I said I would post this, and I'll admit I did rather keep forgetting to...but here we are. ..and yes, I know v0.1 isn't working yet...I got motivated by a documentary on the TTXGP (Charge; great watch if you're a biker/techie/etc), and things just kind of fell into place, so I'm starting it sooner than I had originally planned.

So, on with the story.

A week ago last Sunday, I picked up an '85 Honda V30 Magna. It has a (suspected) thrown rod, so the engine isn't working at the moment, but other than that it's largely in good shape, despite sitting out in the weather for several months. Picked it up for $500 and ~3 hours of driving.

Now, I'll admit, I feel a little guilty tearing up this bike. I love the Honda V4's, and the V30 Magna in particular is a real pleasure to ride. 64HP V4 in a 400lb cruiser? Oh hells yes! Fortunately, the motor is locked up, so my guilt is ameliorated to a fair extent. ...and no, the bike in the background is definitely not an '85 VF700S Sabre that I fell in love with searching for a roller...definitely not...what an oddly specific question.

...anyways, what was I talking about? Oh yeah, the bike.

So, what am I doing to this jewel of the '80's, you may ask? Very simple. I am ripping out that wonderful engine and putting in an (I believe) even more wonderful electric motor.

Enter the HPEVS AC-15.

Paired with the Curtis 1238-6501, at 108V and full throttle it puts out a solid 63 ft-lb of torque up to ~3750rpm before gradually falling off. More than twice the torque the C30 managed at its peak.

Motor is on order from a fellow elmoto.net forum member, and batteries will be on order shortly. ...what and from whom, I have not yet decided..but that's another story.

So, since I neglected to start this thread until I had been working on the bike for over a week (granted, intermittently), here's a bunch of pictures:

Fresh off the truck.

Fuel system and tail pulled.

Cooling system, carbs, instrument cluster, and controls pulled.

Basically, I'm stripping the bike bare and starting from a bare frame. I'll hopefully be pulling the engine this weekend, with Ichbin's help (you're welcome to stop by as well, Altec..or anyone else who feels like it). Once I have that pulled I can clean the frame and start measuring for battery boxes and mounts, motor mounts, etc.

As a side note, this is actually my first ever cross-posted thread. Also available at the below link, if anyone's interested in seeing a different perspective on it. Who knows, you might like what you see and stay.
http://www.elmoto.net/showthread.php?2114-E15-Magna

[xr4man]

what kind of range are you hoping to get with this?

[TLHarrell]

Better question would be:

What is the average current draw of this motor at cruising speed?
And, how much pack storage are you going to fit into this build?

Range will depend heavily on those, plus the controller electronics (how good it is at regenerative braking) and how you drive it. But a ballpark number would be cool.

[xr4man]

that's a little more exact than what i was wondering about. i was thinking more like 10 miles, 50 miles, 100 miles. a much broader range.

[TLHarrell]

I like details.

[Technochicken]

Awesome, I love EVs. I'm actually working on a much smaller personal EV right now. I'm interested to see what kind of battery you will be using. I don't know your budget, but have you looked at LiFePO4 (Lithium Iron Phosphate)? They have high charge/discharge rates (especially the ones by A123 Systems), nearly the capacity of LiPo, but without the propensity to violently explode when punctured or overcharged. They are pretty expensive though.

[x88x]

what kind of range are you hoping to get with this?

75 miles at 80% DOD (DOD == Depth of Discharge, ie, 20% left or 20% SOC == State of Charge. Most lithium chemistries last much longer and behave much better if you don't take them below 20% SOC).

What is the average current draw of this motor at cruising speed?

Depends on the vehicle weight, aerodynamics, rolling resistance, etc, etc. I'm expecting an average of ~125Wh/mi though (more at high speed, less at low speed), and that seems to be pretty much standard with well done motorcycle conversions. The controller I'm using can put out a max of 550A at a max of 108V for as long as I can keep it cool enough to continue operating. Cruising though, I don't expect it to top 75A (est ~60A at 60mph).

And, how much pack storage are you going to fit into this build?

Currently looking at ~13kWh (108V 120Ah).

Range will depend heavily on those, plus the controller electronics (how good it is at regenerative braking) and how you drive it. But a ballpark number would be cool.

The motor and controller are quite good at regen. That being said, I'm not going to touch it. 90% of the braking is done with the front wheel on a motorcycle anyways, so imo there's no point in complicating matters.

Awesome, I love EVs. I'm actually working on a much smaller personal EV right now.

Awesome! ...buildlog? Come on, I showed you mine, now you show me yours.

I'm interested to see what kind of battery you will be using. I don't know your budget, but have you looked at LiFePO4 (Lithium Iron Phosphate)? They have high charge/discharge rates (especially the ones by A123 Systems), nearly the capacity of LiPo, but without the propensity to violently explode when punctured or overcharged. They are pretty expensive though.

Ah, the eternal battery debate.

Yes, I am quite familiar with LiFePO4 vs LiCo vs LiMn vs LiSNiWhateverTheHellPanasonicsNewCellsAre and all the pros and cons. I say this not to shut down any debate, just to say that yes, I am very aware of the available options. I've been spending the last year and a half learning what I can, where I can, and have amassed quite a bit of (theoretical and second hand) knowledge on the topic...a fact that is not always very helpful...

My original thought was to use the Sinopoly LFP60AHA (B) cells, since I do really like the idea of the large format prismatics. Unfortunately, when I went from my original idea for a frame ('82 Suzuki GS1100) to this, my available space decreased quite a bit. Fortunately, I like the smaller frame enough that I'm willing to work around that. Upon further inspection, I am not convinced that the Sinopoly cell will actually fit. Additionally, the quote I got from Sinopoly included a ~2 month lead/delivery time and my goal is to have this largely complete by May 5th for an electric motorcycle convention in NY. This sent me back to the drawing board.

With the need to decrease my volume without decreasing capacity, I was driven to one of two options:
1) Headway 40152S
2) Turnigy 8Ah 25C Nano-tech

What about A123 you ask? Well, let me ask you one thing. ...have you ever tried to actually buy A123 cells? The M20's, not the M1's...no way in hell am I sticking together 1,650 of those things... They're either a) extremely expensive (Mavizen) or b) difficult/time consuming to actually get ahold of (various back door Chinese retailers). And either one requires quite a bit of work assembling them into packs. So will the Headway or Turnigy cells, but not nearly as much work, I don't think.

So, looking at my options, I find:
1) Similar price point (Headways are a bit more expensive, but will likely cost a bit less in hardware building the pack).
2) Both will provide more than enough current.
3) Possibly similar charge cycles (distinct lack of hard data on the Turnigy's)...and let's be honest, even if I only got 400 cycles, 30k miles is a good long time on a motorcycle.
4) Turnigy's have ~30% greater energy density by volume and ~60% greater by weight. On a motorcycle, these are both huge factors to consider.

Why do I say the nano-tech's instead of the normal Turnigy cells? Because from what I hear their QC process is a lot stricter with the nano-tech's and they are a lot more stable and abuse-tolerant.

I'm leaning heavily towards the Turnigy's at the moment, but that is liable to change at any minute. I have read volumes on them, I have seen numerous stories of people using very large volumes of them for years without issue, I even have ~300Wh of the cheaper Turnigy 20C cells that I use to play around with scooters and stuff, and have had them for over a year with no issues. I still keep coming back to the horror stories though...and the idea of dropping $6k on them...and having them sitting between my legs going 60+mph... ...there's a very good chance that I'll end up going with them, but they still kinda freak me out...but hey, motorcycles are supposed to be dangerous, right? ...right?...

Incidentally, if you're interested in CCing various batteries, the below might be of use to you. I put it together after getting sick of running around to a zillion different websites every time I wanted to compare cells.
https://docs.google.com/spreadsheet/...Vloa3dreVlJeEE

[x88x]

Oh, and for TLHarrell, here's the power curve of the motor in question. This is at 72V, and I have it on good authority from people who have actually used and tested this motor (or similar models by the same manufacturer) that the modification with higher voltage is to just basically move the torque drop off out proportionately to the increase in voltage.

[Technochicken]

What about A123 you ask? Well, let me ask you one thing. ...have you ever tried to actually buy A123 cells? The M20's, not the M1's...no way in hell am I sticking together 1,650 of those things... They're either a) extremely expensive (Mavizen) or b) difficult/time consuming to actually get ahold of (various back door Chinese retailers). And either one requires quite a bit of work assembling them into packs. So will the Headway or Turnigy cells, but not nearly as much work, I don't think.

Good points. I've seen their cylindrical cells on Hobbyking, but they are 18$ per cell! I should be able to get my hands on some next year, though, as A123 is affiliated with the university I will be going to.

Why do I say the nano-tech's instead of the normal Turnigy cells? Because from what I hear their QC process is a lot stricter with the nano-tech's and they are a lot more stable and abuse-tolerant.

Incidentally, if you're interested in CCing various batteries, the below might be of use to you. I put it together after getting sick of running around to a zillion different websites every time I wanted to compare cells.
https://docs.google.com/spreadsheet/...Vloa3dreVlJeEE

Thanks for the spreadsheet, that will definitely come in handy! Good to know about the nano-techs as well. I've been leaning towards the regular Turnigy's, just because they are so cheap (relatively speaking), but I may have to reconsider.

[TLHarrell]

My brother in law was building an EV conversion of a K-1 Attack kit car (Honda Accord donor engine usually). He ran on hard times and had to sell it when it was nearly complete. He was using an AC Propulsion drive and A123 cells, and hand assembling packs from individual cells. Might be worth looking up his worklog. Lots of good insight there.

More on the project here: K-1 Attack EV Conversion @ Attackforums

I learned a huge amount from him over the short vacations I've visited and had the chance to help out goofing off at his shop in Phoenix. I have a great interest in electric vehicles, but still sitting on the sidelines until the technology gets to where it needs to be. I'd really love to have an all electric bike. That flat power curve while accelerating is awesome and will surely be a kick in the butt to ride. Hope you're planning on putting some LEDs in that thing, or I may have to drop by and mod it.