# Kostov 9" or Kostov 10" in my Lotus Elise EV?



## Plamenator (Mar 6, 2009)

There are two major differences:
1) K9" 144V weights 45kg vs. 69kg for K10" 144V.
2) K9" 144V handles 200A for 60min vs 270A for K10" 144V.
Therefore K10" has 32kW/55Nm vs 23kW/40Nm for K9" 144V if I remember correct.
Here is a comparison:
http://kostov-motors.com/files/compare.pdf

We actually designed K10" to match (and beat ) W9".
People often compare K9" 144V to W9" as they are of similar diameter.
But this is not correct as W9" is 75kg vs 45kg for K9" hence it is like comparing apples to pears.


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## Yabert (Feb 7, 2010)

Nice conversion! 
If you need a fun car to drive, why don't take the more powerfull motor?
Anyway, I think your weakest link will be the battery. They probably sag beelow 120v at high amps and the motor can't give his peak power at this "low" voltage.

http://kostov-motors.com/tractionmotors/kostovevmotors-and-kits/seriesdcmotorsforelectricvehicles/

K9-144: 1300$, 45 kg, 24kw, 200A/40Nm continuously, kostov rated 75 kw peak.

K10-144: 1750$, 69 kg, 32.5kw, 270A continuously, kostov said this motor compete with popular 9" (9.25"), so probably around 100 kw peak.


But, after all, 80 km/h isn't really fast and probably both motor (with high amps) can give you a 0-80 under 5 sec. with proper gear selection and good tire grip!!!


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## pdhsolar (Aug 31, 2009)

Thanks Guys, I'll buy the K10. I dont want to find that its too slow. I can always add some more batteries if I need higher voltage, but changing the motor would be a real pain as I'm building the battery box above it!

Thanks for your help.

Paul.


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## ElectriCar (Jun 15, 2008)

Plamenator said:


> There are two major differences:
> 1) K9" 144V weights 45kg vs. 69kg for K10" 144V.
> 2) K9" 144V handles 200A for 60min vs 270A for K10" 144V.
> Therefore K10" has 32kW/55Nm vs 23kW/40Nm for K9" 144V if I remember correct.
> ...


Hi plam. I'm putting a K11 in my 3300lb S10 and need a little help with a couple of things. My lithium pack voltage is about 162V. 

1. How much torque would a K11 put out at 1000A at around 3000rpm? (need to select strong enough transmission) 
2. I burned up two armatures in an Advance FB1-4001 (9" motor), the last time by running it at around 3000 RPM at peaks of 75Kw for maybe 10 second stretches up several hills followed by down hill runs at much less Kw for a total run of about 10-12 minutes. Would this motor handle that?

I've burned up two ADC9 armatures and went to the K11 due to being a bit stronger and having interpoles to help eliminate arcing.
Thanks in advance!


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## ElectriCar (Jun 15, 2008)

Oops, I lied. The motor I bought is the K11 192v.


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## Plamenator (Mar 6, 2009)

Hi,

This is a very difficult question. To have some approximation, I need at least a log from the drive that burned your ADC. Essentiually you have put it through a series of overloads. Motors can usually survive 1-2 1000A peaks but not if you do it several times in a row. I also suspect that during downhills the motor had like 0 rpm which stopped ventilation.
When driving with your K11, try to upshift not earlier than 4500rpm, shifting in the 4500-5500rpm range. Do use the termal and rpm protection sensors. Have in mind that termal sensors do not protect you 100% from rapid high amp overloads. It is a good idea to drive it easy in the beginning and make a log so we can see what kind of amps/rpm you get on the hilly area.
K11 192V is identical to K11 250V in parallel field mode:
http://kostov-motors.com/files/prod...5d3fca2c5160d76be63770_perfK250-S192F01.1.pdf
From the graph you can read 500A/180Nm/185V/3800rpm. So at 160V you will get something like 500A/160V/3300rpm. Going to 1000A would further reduce rpm probably to around 2500rpm with torque in the 350-400Nm region.
I hope this helps. Are you using Soliton1?


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## ElectriCar (Jun 15, 2008)

Plamenator said:


> Hi,
> 
> This is a very difficult question. To have some approximation, I need at least a log from the drive that burned your ADC. Essentiually you have put it through a series of overloads. Motors can usually survive 1-2 1000A peaks but not if you do it several times in a row. I also suspect that during downhills the motor had like 0 rpm which stopped ventilation.
> When driving with your K11, try to upshift not earlier than 4500rpm, shifting in the 4500-5500rpm range. Do use the termal and rpm protection sensors. Have in mind that termal sensors do not protect you 100% from rapid high amp overloads. It is a good idea to drive it easy in the beginning and make a log so we can see what kind of amps/rpm you get on the hilly area.
> ...


Thanks for your reply! 

RE downhill comment, no the motor was still energized and turning probably 3500rpm but just at the current needed to maintain speed. The motor didn't seem overly hot either as I know to keep the rpm up to prevent that. 

I've burned up TWO armatures with a Soliton 1 and no, the thermal never tripped EITHER TIME. So if it wasn't heat, I don't know what killed it but it definitely was overloaded amperage wise and there wasn't any arcing that I could tell.

That's part of the reason for my inquiry, I don't want to burn up another motor! I selected this large motor in hopes to prevent that. Plus I plan to run a blower on this one after it gets to a certain temp.


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## Plamenator (Mar 6, 2009)

Usually it is either termal overload of overspeeding that cause armature failure (sometimes both at the same time ).
Maybe you can post some pictures of the melted armatures with a focus on the commutator and the working surfaces of the brushes?

Where is the termal sensor of ADC 9 located? In the stator coils?


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## piotrsko (Dec 9, 2007)

My K11-192 has been working for a while in the lead sled ranger. Up and down 6 percent hills at up to 600 amps max indicated @ about 160V ( battery sag) including 100 degree weather.

Plamenator is spot on on his interpretations. I also suspect the ADC can't really handle high voltage


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## ElectriCar (Jun 15, 2008)

Yes well the ADC9 is rated for 120V @ 500A peak, 28HP I believe. I ran it at 144V for two years with no problems. Upon switching to lithium at 162V and a Sol 1 is when it blew. I know I overloaded it but it never ran overly hot, nowhere near the temp rating of the insulation. I'm an electrician and know you can't over heat them. No photos, sorry. 

When I looked at the first one, no appearances of overheating and it appeared as if one of the bars had opened up as it would turn with a tendency to stop every 1/4 turn I believe, maybe half a turn, can't recall. 

My thoughts are that maybe the torque was so great that something shifted or flexed and broke the connection of one of the windings.


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## ElectriCar (Jun 15, 2008)

The sensor is rated 120C and is on the commutator end in the field windings.


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