Father /son project - Was Honda PCX 150 but changed to Yamaha YJ125 Vino
My son Gabriel will turn 12 in a couple days. He is not a sports fan, he is not really a team player. He is more of a nerdy kind of a little guy. We tried for years to get him interested in all kinds of sports but it's just not his thing. Still, he needs something to get his self confidence up, and work on his problem solving skills. I talked to him about building a small motorcycle that he could use himself when he turns 16. He smiled with eyes wide open and thinks it's a wonderful idea. So I got some funds (very little) and we discussed about what we want to build. The decision for a donor bike came to the Honda PCX 150. He sees daddy riding a scooter and that is what he wants too. Just a cooler looking model
I think that making him learn about planning for the project, making lists of materials, making a list of goals to meet, shopping for parts, doing mechanical work, electrical work, using many tools, learning the technical aspect of such a project would help him build his confidence and show him how to solve problems. He would have many small achievements before the final one of having a functional electric scooter. I think he would learn a ton of stuff that will stay with him for life and I get to spend lots of time in the garage with my boy. Win win.
Here is what I was thinking of. The budget is small for now with $3000 but I can ad a few hundreds here and there if I can hide it from the wife. This includes the purchase of the donor bike which I can get for around 1300 to 1400 dollars for an older 2013 model. The top speed of the ICE version is 65 to 70 mph. We want that or more. We want the acceleration to be respectable, something like 0/60 in less than 8 sec. 60 miles at 60 mph would be nice for range.
So that would be a big battery, maybe over 8kw/h? I am very satisfied with Leaf modules in my present scoot so maybe 20 modules to have 74V and 120ah. But I have no idea of the space I have inside the PCX chassis so this might be to much battery, i don't know yet. Should we go for more voltage less a/h or the opposite? Suggestions are welcomed.
To have as much room for batteries as possible, I was thinking of a hub motor, like a QS Motor 8kw in a 14X3.5 rim. Suggestions are welcomed
Controller? I don't have any experience other than Kellys so I thought a KLS72701-80801 72V 700A SINUSOIDAL. Suggestions are welcomed.
If you start adding up the cost of what I listed you can see that the budget is too small but... I'll figure something out.
I am going with what I know about the vehicle and components, but maybe you have suggestion that will make me realize I should go a different route on one thing or two or maybe all of it
Thanks for reading and I look forward to the discussions.
Last edited by mistercrash; 07 June 2016 at 1610.
Reason: changed the vehicle to convert
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Love this idea!
For 60miles you're likely looking at something in the region of 8-10kWh depending on the drag factor for the chassis - the VX-1 will do about 50miles at about 60mph average on 8kWh and it's about as slab sided a thing as you can get.
I think you're going to find the PCX small for that sort of battery count though. The other thing to bear in mind is that with 20 leaf modules in place, that's a whole hell of a lot of bike for a 16 year old to be learning slow manouvering on. Might be some merit in going for something lighter with less range but more fun - maybe working in a battery swap system for the first rendition. If you started with a cruiser or street chassis you'd avoid having plastics to damage *when* he drops it that first couple of times. Cruiser chassis would give you all of the stability of a scoot as well so it's not like you'd be missing out - and you'll be able to pick up a virago/vulcan/rebel/shadow chassis for pennies I'd guess.
I've been going back and forth between a scoot or a larger motorcycle for weeks and even though I said the decision came down to a Honda PCX 150, I am still open to discussions. The reason I like scooters is because of where we live up here in Canada. The front fairing of scooters really helps extend the use during the colder months. Pair that with a large windscreen and hand warmers on the handle bars and it is possible to ride short distances to work (or school) even at well below zero degrees. Then I think how simpler it looks to go for a brushed motor with sprockets and chain/belt on a cruiser motorcycle.
I still like the idea of a scoot but we have to think about it some more and re-explore our options.
Thanks again and please share your thoughts people to help us make up our minds.
Last edited by mistercrash; 30 May 2016 at 0600.
The kid and I had a good discussion on our options. We are still considering the Honda PCX 150 for the conversion. But we did come to more realistic expectations for range considering the scooter is small and 20 Leaf modules would be quite the challenge to fit in the frame. After all, this is meant to be a commuter to putter around town and maybe use side country roads to go to neighboring towns. It should rarely have any highway use, if ever.
So we thought of going up in voltage to 28S by going with 14 Leaf modules. We still don't have the bike but we think that stripping the modules from their aluminum covers and insulators, we can bring them all together in a metal box that will use the threaded rods to suspend the modules inside it and give the proper compression. We think that box would fit in the chassis where the engine is, but the size of the battery would take the room under the seat so we would lose that storage area. We're fine with that.
Because we are thinking of going to 28S we are now considering the Kelly KLS96601 240A continuous 600A peak running on 116V (4.16V per cell). I would limit the top speed to 50 mph in the controller's software and use the boost function to release the full power if needed.
It's all talk for now and we look forward to more suggestions.
Ray and Gabriel
Last edited by mistercrash; 30 May 2016 at 1619.
Consider the Zoe modules instead of the Leaf units if you're intending to refabricate the pack, they're not as heavily enclosed; also bear in mind that the casing of the leaf cells serves as part of the heat dissipation strategy for them, so if you're removing all that thermal mass and setting the pouches back-to-back, then you may want to keep a close eye on how the center of the pack responds to higher current demands. In the Leaf the pack peaks at about 230A at full tilt, and wouldn't be expected to maintain that for more than a few seconds. If you run that Kelly unit at full tilt you'll be drawing 2.5x that, which may not prove healthy for your trimmed down pack, particularly the center modules.
Aside from that, you assertion of 116V at 600A wouldn't happen anyway, at that sort of loading (20C) you'll find that even these cells will sag quite a bit; on another note, if you did hit 600A @ 116V, that's nearly 70kW! which, I can promise you, will have you doing a hell of a lot more than 50mph on a scooter!
Realistically, you're looking for about 13-15kW peak for your application. Configured to run at 96Vnom, this would require 13 leaf modules in series for a peak voltage of 108V, capacity of 5.8kWh, a very sustainable power delivery of 7.5kW rising to a 60s-peak of about 22kW. Assuming a fairly light moped, level roads, and 50mph average speeds, that ought to get you about 35-40miles if you're judicious with the throttle.
Thank you Spoonman,
You make a good point about thermal mass, the idea of stripping the Leafs was only if it absolutely becomes necessary to make them fit, but if they fit with their casing on then for sure we will leave the modules intact.
If the controller sees a 600A peak, it's only for a second in hard accelerations. From my experience with my other scooter, which has a KLS7250D controller rated for 400A peak with a 5kw hub in a 12'' rim, I get 27kw peak on acceleration on that scooter and it's exhilarating, so I want that on this build. Top reading I got from the CA is 364.4A at 75.1V. It has 10 Leaf modules in it, it takes off the line faster than most cars and there is no hill I can't climb with it, accelerating hard all the way up.
At top speed (55 mph) the draw on the battery hovers around 100A, I'm sure the Leafs can take that for the whole cycle without getting warm. I have a thermistor installed in the middle of the pack to monitor the temp. Without anymore knowledge other than what I experienced with the system I run on my other scooter, I am thinking that this KLS96601 controller might show peaks of 520A max with the Leafs saging to maybe 100V for less than a second on hard accelerations, with the draw settling down very fast to 100A or less as the scooter gets to a programmed top speed of 50 mph. 52kw peak capability should take this scoot up to top speed in around 4.8 seconds lol. Maybe less.
I know what I know and I don't know much so I very much appreciate your input, I'll go look for info on Zoe modules.
Raymond and Gabriel
Last edited by mistercrash; 31 May 2016 at 0827.
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We sat down last night and made a short list of what we would need to build this project and how much money would be involved. It sure ads up quickly.
Honda PCX 150 - $1400 (estimate, can be a bit more or a bit less)
Kelly KLS96601 - $800
QS 8KW hub - $850
14 Leaf modules - $2150
Misc. - $350
If the bike has a fuse box, I would want to replace it with a Motogadget M-UNIT V2 so that would be another $300. Not to mention the ''misc.'' often ends up being a lot more than expected.
What did I get myself into
about the Leaf modules, sag and temp,
i often log my rides, i have 26 Leaf modules, paired by 2. The graph below shows all the cells voltage during the ride. You can see they did not sag that much, even when amps peaked at 480 amps towards the middle of the ride. The greenish cell below the others is not good data, it's cell number 13 that was behind a loose busbar, now fixed.
ABout the temp, they never go above 26 C, 28 maybe. Really not an issue. Your motor and controller will heat up much before your cells. Cell temperature might be an issue if you're racing and you water cool your controller and motor. BUt for legal road riding, it can't be an issue i think.
Bike is about 300 kgs.
I would not recommend opening up the Leaf packs, could be destructive, check out the video a guy did, it's linked on the Leaf thread on our forum. you're not going to gain much space in thickness doing this, not worth it in my opinion.
Last edited by Hugues; 01 June 2016 at 1118.
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My Leafs stay within a couple degrees from ambient temperature pretty much all the time, and the voltage has not gone below the nominal 3.7V per cell. Although I don't pull as much current from them as you do with your super awesome bike. Living in Canada and riding all year long, we plan to use insulation around the battery and install a heating system using insulated Nichrome wire and a thermostat. A system that plugs in a wall outlet to keep the battery at a constant 24 degrees Celsius when the bike is parked outside when at work or at school. Last winter, on my present scooter, the Leafs I use would sag significantly more when very cold, and a few times I could not even plug in the charger as the battery temp was below 5 degrees Celsius (I don't charge when battery is below 5 degrees just to be safe).
The more I think about it and the more I am convinced that you guys are right in leaving the modules as is. If more room is needed, I think modifying the frame to get that extra centimeter here and there if needed would be much better.
Thanks again for the useful data,
Ray and Gabriel
Last edited by mistercrash; 01 June 2016 at 1157.
I think this project with your son is awesome, great bonding time that he'll remember his whole life. You can always add a "Givi type" top trunk in the back for a couple additional batteries and everyday storage.
Do you guys think the leaf batteries can handle 500A continuous and 800 A peak discharge current? I wrote Emsiso about their controller and that seems to be their requirement for the Emrax motor.
Current R1200RT, previously FZ1, HawkGT, Nighthawk 650, XS650. Loved every single one of them, now it's time for an electric bike!