# D&D ES-31B and Solution Jr for e-Kart



## winzeracer (Apr 3, 2012)

Hi all,

I have decided to redesign the kart that I have not built yet( ignore what my webpage says for BOM). I am proposing to go a bit wild and run the following:
- D&D-es-31B http://www.evdrives.com/dd_motors_ES-31B.html, 
-Sjr controller http://www.evolveelectrics.com/Soliton Junior.html
- 30s4p 38140S Headway pack http://www.evassemble.com/index.php?main_page=product_info&cPath=2&products_id=21

I know that the Sjr is overkill, however I like its features and will most likely use it for a future build as well( small track car next year)
Important features for me are high acceleration, hopefully top speed of ~80mph and fast recharge times at the track. My questions are the following:

#1) With this battery pack I should have 96v and 48ah these cells claim a constant 10C (problably only 2.6-2.8v) ~38Kw, Sound right?
They claim recharge at 60amps, will they actually hold up to say a 50amp charge and last over 500 cycles?

#2) I have estimated that the Kart, which is a shifter kart chassis, will weigh ~500lbs with me on it. This will need killer brakes. Do you think it will have trouble turning?

#3) I cannot find any specs on RPM for this motor, so that I can come up with gear ratios, any idea what RPM this motor will spin at ~38kW (52HP)?

Any other input about this setup is welcome. On my first design for this kart I severly under designed the system so I want to steer clear of that this go around.

Thanks,

Brock
www.winzeracer.com


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## somanywelps (Jan 25, 2012)

*Controller*: You're not going to want a Jr. in a track car.

Use a kelly or curtis or something lower key for the cart.

If you have a track car you're going to want a soliton 1 minimum.
*
Motor*: This is far better than yours: http://kostov-motors.com/tractionmo...-dc)/seriesdcmotorsforelectricvehicles/k996v/

Click on the performance curves pdf for the optimals and whatnot. That goes up to 500A, the Kellys go up to 1000A-1400A or something.
*
Batteries*: Headways will work. I'd still vote for A123s if you can.


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## winzeracer (Apr 3, 2012)

somanywelps said:


> *Controller*: You're not going to want a Jr. in a track car.
> 
> Use a kelly or curtis or something lower key for the cart.
> 
> ...


Somany,

Again you fail to understand this is a track KART (500 lbs with driver) not a track car, no room or need for S1,or k9. On the batts any reason you prefer A123? You never really give any reasons for any reason for anything. Thus I personally find very little value in your posts. Offering insight is much more valuable than statements.  

Brock


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## somanywelps (Jan 25, 2012)

winzeracer said:


> Somany,
> 
> Again you fail to understand this is a track KART (500 lbs with driver) not a track car, no room or need for S1,or k9. On the batts any reason you prefer A123? You never really give any reasons for any reason for anything. Thus I personally find very little value in your posts. Offering insight is much more valuable than statements.
> 
> Brock


I'm perfectly aware that it's not a track car. I said you don't want a Jr. in a track car. It's also overkill for this cart. You'll be FASTER with a kelly due to the low voltage(vs the soliton jr.) (and higher amperage) of a kelly controller.

A123's are less expensive, have an easier form factor than headways, and have a higher discharge rate. Some people have gotten a dead cell or two though.

The k9 is 45 kg vs the D&D's 37kg, but this gives it more overload (heat sink), it has MUCH more peak torque (and by proxy, power). It also has a nominal RPM of 6400.


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## Ziggythewiz (May 16, 2010)

winzeracer said:


> will weigh ~500lbs with me on it.


Sounds quite unsafe, I mean, lots of fun! After driver, battery, motor, controller, tires, what does that leave, 50 lbs for the frame, brakes, etc?

I have an ES-31B running in my bug. I understand it to have a max safe RPM of 6000. It gets a bug up to 70 with 120V, so a kart at 80 should be no problem with the right ratios. It's a smaller motor in EV land, but in kartland is probably rather large. You'll probably kill yourself before you do the motor.

I suspect RPMs for a given voltage will depend entirely on your gearing, but I'm no expert. I know how fast it runs on a bug, particularly at 120V, but I've also messed with 96-132.


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## Batterypoweredtoad (Feb 5, 2008)

If you are going to use the controller and motor in a future small car I would use a minimum of the k9 220V and the Soliton Jr. That would just be adequate for a very light car with a finished weight of sub 1500lbs and it would be peppy not fast (think normal Miata not Turbo Miata or Corvette). IF you end up using the K9 220V I would use the 8ah headways and stretch that voltage as far as you can to help get those RPM's up on that K9. While slightly undersized on the race car, this setup should give you sportbike style acceleration in the Kart.

Here's some 8ah headway testing done a few years back: http://visforvoltage.org/forum/8523-headway-cell-testing-preliminary-study 

The A123 20ah pouches are nice, but fitting 90 or so on a Kart is going to be tough and weigh around 100lbs.


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## Yabert (Feb 7, 2010)

I think the kart of my friend is a good example of what you can build (0-60 less than 4 sec and 12 sec on 1/4 mile despite it weight over 550 lbs with driver).

http://www.youtube.com/watch?v=YxUlJjjREZE&feature=channel_page
http://www.evalbum.com/1205

How he do this? Powerful battery, powerful battery, powerful battery.... and an awesome controller!

If I were you, I would start by thinking about a powerful battery pack composed by 60-80 lbs of A123 AMP20.


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## mora (Nov 11, 2009)

Keep weight down and punish that little motor. Watch motor temp and brushes closely. I believe 600 motor amps will give good acceleration for any 500lbs vehicle. To keep your amps up you need high voltage. Soliton Jr will definitely be the best choice regarding voltage range. You'll want at least that 120V, maybe more if your motor can handle it.


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## somanywelps (Jan 25, 2012)

Yabert said:


> I think the kart of my friend is a good example of what you can build (0-60 less than 4 sec and 12 sec on 1/4 mile despite it weight over 550 lbs with driver).
> 
> http://www.youtube.com/watch?v=YxUlJjjREZE&feature=channel_page
> http://www.evalbum.com/1205
> ...


I was looking for that video to post  

http://www.youtube.com/watch?v=bERjkSTYOdU


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## winzeracer (Apr 3, 2012)

Somany,

Ok now I am with you on the A123's though the Amp20's are a bit pricey. I am looking at these http://www.alibaba.com/product-gs/519279573/Lifepo4_26650_Battery_A123_26650_2.html 
Where is a reputable, affordable place to buy a123?
I did not find any kelly's above 900amp and even those only had 450a conts, Where did you see the 1000a-1400a kelly?

Ziggy,

Ya the frame is 75lbs with no tires, I guess it will be dangerous and FUn 
Thank you for the motor info.

Yabert,

That is bad kart, thanks for the vid I am considering using the same A123 pack 40s10p for 132v 23ah. Any idea how long his pack lasted while playing pretty hard? The A123 do look to be much better than the Headways with MUCH better C rates.

Do you think this is legit? http://www.ebay.com/itm/100-A123-sy...e_Batteries&hash=item2c60d37c4c#ht_3458wt_735

I also pm'ed Ron to ask about the Haiyin pouches, but after looking into the A123's They look really nice 30C continuous(~70amp) and 60C burst. That is crazy! I would not be pack limited with this type of setup, but play time might be pretty short.

Brock,
www.winzeracer.com


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## somanywelps (Jan 25, 2012)

winzeracer said:


> Somany,
> 
> Ok now I am with you on the A123's though the Amp20's are a bit pricey. I am looking at these http://www.alibaba.com/product-gs/519279573/Lifepo4_26650_Battery_A123_26650_2.html
> Where is a reputable, affordable place to buy a123?


Have not done it myself, look in batteries section


winzeracer said:


> Where is a reputable, affordable place to buy a123?
> I did not find any kelly's above 900amp and even those only had 450a conts, Where did you see the 1000a-1400a kelly?


 http://kellycontroller.com/kdh-seriespm-controller-c-25_37.html


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## Yabert (Feb 7, 2010)

Don't bother to play with 400 small cells. Their assembly is a real pain! The technology evolve, so evoluted with it.
The A123 26650 are so 2008...

I think a pack builded with 76 AMP20 (38S 2P) can be awesome with a potential of 100-120 Kw of peak power (about what I have in my 1900 lbs car with sporty acceleration....).

If you don't need that much power, a small 26S 2P pack (60 lbs) coupled with an Alltrax SPM 72650 (8.5 lbs) can give you a good 50 hp at wheel if your motor have a correct efficiency at 740A.
50 hp in a 450 lbs kart is a serious power ratio.... comparable at some 500 hp sport car.



winzeracer said:


> That is crazy! I would not be pack limited with this type of setup, but play time might be pretty short.


Short time is relative when you accelerate to 50 mph in 3 sec. and you need 10 seconds to recover from your emotion....


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## MN Driver (Sep 29, 2009)

Yabert said:


> Short time is relative when you accelerate to 50 mph in 3 sec. and you need 10 seconds to recover from your emotion....


Umm, can I use this as a quote in the future? I love it!


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## winzeracer (Apr 3, 2012)

Ziggythewiz said:


> Sounds quite unsafe, I mean, lots of fun! After driver, battery, motor, controller, tires, what does that leave, 50 lbs for the frame, brakes, etc?



This is what the an experinced Kart racer and owner of a Kart shop said when I asked him about the 500lb kart:
_
Hi Brock

Adult karts are designed to run at about 375 lb. with driver. There are classes which require the kart to run at 405 lb and already it becomes a noticeable problem to get the kart to turn like it's designed to. When you get to 420 lb+ it starts to become a lost cause. Without getting too much in to the physics, the springs involved just aren't designed to work in the weight range, it's like an adult jumping on a children's bed. Unfortunately even race karts will understeer terminally when driven too slow or have cold tires, so if you're planning on driving in parking lots, etc, the problem will be even worse. 

There is an old saying in racing, "power is nothing without control." I have a friend who bought a 40 HP shifter kart, he doesn't drive very well and the kart isn't set up very well, so at a given track I can do a faster lap time in 13 HP four-cycle kart. Unless you are drag-racing, you may be better trading off some of that power for weight reduction, this will make a better driving experience.

One more piece of food for thought, there is another old saying in racing: Horsepower sells motor cars, but torque wins motor races...

Take care!_

With that out there I DO want to be able to turn and make it around the track, I dont want a pure drag racing kart. So the new goal is <400lbs, here is my proposed weights as weighed by bathroom scale:

Frame: *75lbs*
Rims and Tires: *17.5lbs*
Driver after -10lb diet)  * 180lbs*
Side pods( batt mount) * 5lbs*
Misc *5lbs*

*TOTAL non-electrical 282.5lbs
Weight allotment electrical 117.5 lbs*

So here is the challenging part. Proposed electrical allotment breakdown:

Batteries: 84 Haiyin Ultra Proforrmance 6ah 3.7v nom-- 103v Nom 18ah 
This should give good current even at voltage drop to 3v
3v*28cells*18ah*33.33C = 50kw
( could have complete packs that could be changed at pit stop)
Battery pack wieght with pack construction materials *40lbs*

*Weight left for motor controller and wiring 77lbs*

Solution Jr(maybe) *12lbs*
wiring and Rev. cont *5.5lbs*

So all I need is a magic 50lb 50kw motor. haha

*This leaves 50lbs for a mean motor...Hmmmm? any Suggestions?*

I put a request in with these guys anyone heard of them? http://www.plumquick.com

Thanks,

Brock
www.winzeracer.com


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## Ziggythewiz (May 16, 2010)

Those are some tight margins. You may need some low-carb engineering to get that thing under spec!


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## somanywelps (Jan 25, 2012)

Drop to 7" motors?


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## MN Driver (Sep 29, 2009)

somanywelps said:


> Drop to 7" motors?


The D&D ES-31B is a 6.7" motor. It's really long proportionately at 15" though. I think the Warp Impulse 9 is an inch shorter as a comparison. Kostov 9's are 14" too, again only mentioning this as a comparison.


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## Yabert (Feb 7, 2010)

winzeracer said:


> So all I need is a magic 50lb 50kw motor. haha
> 
> *This leaves 50lbs for a mean motor...Hmmmm? any Suggestions?*


Do you have a large budget? 

Dual Agni 95R can be awesome but pricey: http://www.electricmotorsport.com/store/ems_ev_parts_motors_agni_b95r.php
Or maybe abuse from a single Agni 111R: http://endless-sphere.com/forums/viewtopic.php?f=30&t=33440&hilit=agni


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## winzeracer (Apr 3, 2012)

Yabert said:


> Do you have a large budget?
> 
> Dual Agni 95R can be awesome but pricey: http://www.electricmotorsport.com/store/ems_ev_parts_motors_agni_b95r.php
> Or maybe abuse from a single Agni 111R: http://endless-sphere.com/forums/viewtopic.php?f=30&t=33440&hilit=agni


Wow Yabert that agni 111rdr is a killer and only 26lbs! Just need to squeeze the nearly $3k price into the budget, I think one of these would be better and easier install than dual 95r's. Thanks for the info. Still waiting to see what plumquick says.


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