YZ250F 2014 Build With QS 138 70H V3 Motor and 450A controller Part #1 and Part #2

[dbc105]

Don, I guess a better question about the KTM battery would be did you use the same cells as the Yamaha and the same voltage and was it built in the same style? The Yamaha has a frame that allows the battery to stand up between the 2 top rails but if the KTM 150, I think is like my 300 it has a single backbone. Maybe 3 cells wide?

 

[DonCox]

Don, I guess a better question about the KTM battery would be did you use the same cells as the Yamaha and the same voltage and was it built in the same style? The Yamaha has a frame that allows the battery to stand up between the 2 top rails but if the KTM 150, I think is like my 300 it has a single backbone. Maybe 3 cells wide?

If I built another KTM, I would use the same cells, Molicel P42A. Right now they are less expensive for the amount of energy they pack. The Yamaha is running an older battery type, Sony 18650 VTC6. They do provide the current, 30A, and 3000w of capacity. For less money per cell, the Molicel P42A's, provide 45A and 4200W of capacity. They are a bigger cell, 21700. The Yamaha has 280 cells for 42AH and 420A (theoretical), I actually only get about 370A, and weighs about 35lbs, but the KTM has 320 cells for 63AH and 720A ( theoretical) probably more like 650A. It weighs about 52lbs. The more Amps allow for you to stay in the 250-350A range longer, therefore more miles. When you are trail riding, you are more in the 150A range.
For your KTM I would build it the same as the first KTM, if your frame would allow that much battery. It is easy to scale it when it is being built.

 

[dbc105]

I have a '72 Suzuki T500 vintage race bike, I used a 16v pack with 8 16850s to power the ignition, in a total lose using a Ford pickup and reluctor and a GM HEI module and a Dynatec dual fire coil. Big spark. Cool to hear about the 21700, less items to deal with.
I saw mention of charging but no mention of chargers. I use a standard hobby charger to charge the battery on my race bike, iis that what you use to charge these? I saw you saw that when you were not on the track you were on charge and I know I can connect mine to 120ac or a 12v car battery.

Thanks Don

 

[DonCox]

I charge mine with 2 chargers. The battery is divided into 2 packs. Each pack is 72V 21ah. Each charger is 72V ( nominal 84V peak) and 10A. I use 2 smaller ones to allow charging on 120VAC. Any larger than 10-12A and you need 240VAC. It takes about 30 minutes to go from 50% battery to 80-90%. About an hour 15 minutes to full charge. To run both chargers, I need about 2000W of a running watts generator. That is a little larger than most 2000W peak power generators. Only a few tracks I go to have power

 

[dbc105]

I see a few of these on Amazon, is there anything I should look for or look to avoid? They look to be chargers for ebikes or EZGOs. the ones I'm seeing are pretty reasonable. I think I gave $75 for the hobby charger I use for my race bike. LOL, I know the guy that owns the store where I bought it and he programmed it for me. It is not such to do 10a though. It is for charging a RC plane or car.

 

[ProperHooligan]

The power on my YZ is only about 35hp ( 370A at 72V = 27KW=35hp) There are pluses and minus's to that power number, but the torque is the fun part. I ride most of the time in 81 to the 72V range. If my battery was larger, like the KTM 2017 150SX I built , 63AH, It can provide 450A at 72V for longer ( it has a max of about 700A). 72v x 450A = 43HP . I have not ridden it at 450A, it needed a cooling system on the Controller. Manny Guerrero has built a few with this combo, 450A and a Controller Cooling system. He owned an Alta , and he said the QS motor at 450A, is all of Mode 3 (40HP) on the Alta. And over 20lbs of less weight. The KTM with 63AH or 4.8KW battery weighed 245lbs. My YZ with 42AH or 2.8KW battery weighs 221lbs.
Check out this new build by Manny Guerrero of a YZ (20S12P P42A Molicels, 540A and 3.9KW battery) and 3 modes , 1.) 250A , 2.) 350A , Mode 3 or Ludicrous, 450A, and I think he said it weighed 230lbs. The new owner of this bike should riding it soon. I hope my calculator didn't make any gross mistakes, lots of numbers... What I know is this QS 138 70H V3 and the EM260 controller makes a fun bike.

Hey Don, you mentioned cooling for the controller at high amperage a couple of times. Could you elaborate on some solutions you've found or heard of? I've got a kit coming from ElectroandCompany with the EM260 for a CRF250R.

 

[DonCox]

ProperHooligan, what a great name. You are getting the best kit out there right now, from the guys at ElectroandCompany. I'd be glad to help you. I answered a lot of these questions for another person in a private discussion, so I just copied it and will put it here. I am sure you will have more questions after you read it. Go ahead and ask. I will try to help. The battery he is using is for a SurRon, (ChiBatterySystems.com Gladiator MAX &2V 51AH) it can fit some bikes, but it is a good price. It is 5.86" x 5.86" x 17.5" and 51AH Molicel P42A cells in a 20S11P configuration, with enough juice to get you the 450A for a while. I built a 2017 KTM with 20S16P same cells, and that could give you 450A for a long time. But 450A is Trenching power with this combo. Here is the info ( this info was for a 2015 YZ bike) and I look forward to your questions.

Here are the other parts you might need. It looks like the battery you are going to use can get you between 420 and 540Amps, so you might need the cooling system. Try it without it. I am not running it now, and I push 370Amps, and the controller has not yet overheated. A thermal alert should show up?? The controller mount I will make , they will fit without interfering with anything. Use one stock right radiator,(It's got the cap), and you might have to make up hose size reducers. Use this Power Supply, because it has a soft start circuit, and won't arc your switch. This pump is for brewing beer , so made for hot water, and the cooling blocks will fit, but larger ones can also be made to fit. (on the bottom of the controller.)
Pump https://www.amazon.com/gp/product/B07JD8PXSR/?tag=sce0f-20
Power Supply https://www.amazon.com/gp/product/B07GNTC1D7/?tag=sce0f-20 You need to seal both end of this , or pressure washing will kill it. Seal all the way around these ends in the picture below (red lines)
Water cooling blocks https://www.amazon.com/gp/product/B07VFGW4JZ/?tag=sce0f-20 (They also have larger ones on that site)
Battery Switch Amazon.com
1K 10W resistor noise suppression around the Master on off switch (Second picture of the underside of the Master on/off switch)

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[dbc105]

Don, do you have a good source for the Molicel P42A cells?

 

[DonCox]

Don, do you have a good source for the Molicel P42A cells?

Yes I do. Molicel/NPE INR-21700-P42A 45A 4200mAh Flat Top 21700 Battery - Authorized Distributor
They have them and with quantity discounts.

Building your own batteries is very tricky and can be dangerous, I would find a prebuilt. Here are some ideas with those cells. These cells seem to be the best right now for power and cost.

This is Gary Little at Vextrex, who is on this forum, and he can build you packs with those cells in various configurations.

General - 72V 50aHr pack of Molicel P42A cells connected with copper

The Vextrek prototype lithium ion pack for dirt bikes is almost ready! Our goal was to “GO BIG” on everything. This is a 72V 50aHr (20S/12P) pack of Molicel P42 cells connected with .25mm thick copper. Since cooper is 4x more conductive than nickel, this pack can easily handle high current. As...

electricdirtriders.com

Also ChiBatterySystems.com have some using the same cells but more in the SurRon form factor.

Also ElectroandCompany.com sells a 20S6P and a 20S8P packs with the same cells.

 

[dbc105]

Great, thanks Don.

 

[dbc105]

Don, I watched you videos, nice bikes. Have you used a 90H motor and besides the gear reduction, what is the difference between the 90H and the70H? Thanks.

 

[DonCox]

No I haven't used the 90H gear reduction unit. It is wider than the 70H motor, so you will have a bigger problem with the brake pedal, the motor is heavier, and there is right now more power than I need in Mode 3 with a 70H motor at 350 AMPs and I can go to 450AMPs if I ever need it. I am not a Pro rider, and there is scary power with 350AMPs. I am sure a pro would want more, but I am older and I am not going to go that much faster in my foreseeable future.

 

[dbc105]

I didn't know if the 90H was a bigger motor or not. I guess any of them would still be limited by the capacity of the controller. What little I know about the Zeros, it seems they use one motor in different bikes at different power levels.
I watched your battery build vids. Nice work. I saw one comment about the cells having a high resistance. I don't know what he means by that. I also saw the KTM 150, nice bike. Looks like a good woods bike.

 

[DonCox]

So I turned 78 last month. All is well. The YZ250F 2014 Electric is about 6 months old and it has 300-400 moto laps on it, ridden most by a older rider, but it has been near flawless. The battery packs have given me a few problems, but this is their second career on this bike. They have needed a little maintenance. Here are 2 YouTubes, one of the new build I just finished on a 2003 YZ with the same motor and controller as the YZ 2014. It is in Mode 2 (about 175A) and and I have only ridden this a few miles on the streets by my house, then the second YouTube is the YZ 2014 in Mode 3 with over 300A and Flux Weakening. You can hear the thing spool up higher, and my god the power is sooooo fun.

Here are a few pics of the new 2003 YZ It has a 3.6KW battery (50AH), and weighs 239lbs

 

[DonCox]

I have a '72 Suzuki T500 vintage race bike, I used a 16v pack with 8 16850s to power the ignition, in a total lose using a Ford pickup and reluctor and a GM HEI module and a Dynatec dual fire coil. Big spark. Cool to hear about the 21700, less items to deal with.
I saw mention of charging but no mention of chargers. I use a standard hobby charger to charge the battery on my race bike, iis that what you use to charge these? I saw you saw that when you were not on the track you were on charge and I know I can connect mine to 120ac or a 12v car battery.

Thanks Don

I have 2 x 10A 120V chargers, since I have split my battery into 2 packs, and charge them both at the same time. 120V is available some tracks, but I have a 3500W inverter generator that can run 2 15A chargers. That brings the battery back to 80-90% in 45 minutes from about 50%. 15A charger is about all you can get out of a 120VAC outlet, and or a Honda 2000W inverter generator. The 15A chargers is what I am putting on all my new builds. The 2 10A chargers are my older ones that just still work.
This is the link to the generator, it is the same weight and size as the Honda 2200W , twice the power, and half the price. MXR3500. It uses 1/2gal of gas for a ride day at the track.
3500 5500 Watt Dual Fuel inverter Generator Generators Portable 3KW for Home RV | eBay