# Warp9 and K10 Comparison



## Yabert (Feb 7, 2010)

*Re: Warp9 or K10?*

Hi

It seem you have done your homework before ask the question. Good thing!

Some error:
W9 efficiency peak around 87-88% and K10 can take way more than 144v.

I like since a while now the Kostov motors for her capability to take 220-250v nominal, but if you never think build a battery pack over 200v, the Warp 9 have proof many times it can take abuse and give great performance and reliability.
Both motor can be good, but at this ''low voltage'' I prefer the W9. Especially if you think used a 1000A controller!



shardbearer said:


> My budget is somewhat limited, so I have only 96V of LiFePO batteries. How will this undervolting affect motor power? It should theoretically only affect top speed, not acceleration, right?


Why 96v? Do you know than 96v 100Ah (for example) will give you similar range than 160v 60Ah for similar price?
Low voltage won't change the first part of the acceleration, but the torque (who accelerate the car) will fall down faster compare to higher voltage battery pack.


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## MN Driver (Sep 29, 2009)

*Re: Warp9 or K10?*

One thing I noticed when I was at EVCCON 2012 was that everyone who used a Warp motor who showed their Soliton settings or talked about them was that they were limiting their voltage in the 150-170 volt range. 170 volts is the max that Netgain recommends you run their motors, there are a few Youtube videos of 1000 amp runs on dynos where the commutator is arcing so running a higher voltage, I don't think should be paired with 1000 amps. I'm not certain of the limits for the Warp.

The Kostov K10 is different it uses interpoles so you don't need the brush advance to prevent arcing and the commutator won't get as hot. You are moving the critical hot area from the commutator, which is fragile under abuse, to the windings of the motor which can be better monitored with a thermistor(I wouldn't buy a Kostov without one, I bought my K9 HV with it installed, they bury it in the stator for you which is hard to do as an afterthought, it's a dirt cheap option that I think nobody should go without). The Kostov K10 is 144v nominal, not max. For example the K9 HV is 220v nominal in its high voltage winding setup but you can push 270v through it under overload(higher than nominal amperage), just pay attention to motorspeed so you don't blow past the 7000RPM maximum rated speed on the 9" Kostov.

The K10 was built as the direct competitor to the Warp9 IMHO the K10 is a better motor but I think a step up to the K11 is even nicer but you are running a lower voltage system so this wouldn't be a good option since it is wound for a higher voltage.

You'll hurt both top speed and acceleration, you'll need to shift earlier because your torque drops off at a significantly lower RPM, you'll be pumping higher motor amps because you don't have the voltage to have good performance at higher RPM so you'll have a hotter motor and the setup will be less efficient when you are dogging it with high amperage.

What size pack are you going with and which controller? What is your conversion vehicle? With 96 volts, what Ah capacity LiFePO4 cells are you using? If you are going with 100Ah cells, you could go with a 160v 60Ah pack or a 240v 40Ah pack. Either way you go, with a small capacity pack, say 9.6kwh in the above examples, you need to either get some higher power cells such as CALB CA(gray), A123(pain to fit/install the pouches safely), or some other cell that can withstand short bursts of higher acceleration power needs. 9600wh * 10c = 96000kw subtract voltage sag and efficiency losses in the motor and you might get nearly 100 horsepower but only if you go with a 240v 40Ah CALB CA or better pack but this really is pushing the limits and I personally wouldn't want to subject that load to them for more than about 15 seconds at a time with a good cooloff period in there. The 160v might sag a bit too much, although you would be sagging a 240v 40Ah pack a bit too but it will still be able to outperform the lower voltage pack.


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## shardbearer (Feb 3, 2013)

Thanks for the advice. I was thinking of the Mazda MX-5 with 30 100Ah Winston cells and a Soliton1, but this is still in the planning phase and nothing is set in stone. I chose Winstons over CALBs because they're slightly cheaper and have Yttrium, which is supposed to help in the cold, and it's below freezing for 4 months a year here. Now that I think about it, I do think I'd be better off with 50 60Ah, which would be 160V. Only 180A continuous current though, and the most I could upgrade it would be 16kWh.

Right now I'm leaning towards the Kostov, because of the interpoles, lower temperature, higher voltage, and higher current. And I can get a cooling fan that bolts onto the back. Is the thermistor standard? I don't see any options on the website.


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## MN Driver (Sep 29, 2009)

The thermistor was a $20 option through my dealer at the time that I bought my motor. I'm waiting for my motor to arrive still since my dealer doesn't stock the K9 HV, I'm expecting it 2-3 weeks from now.


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## mulderfox (Aug 4, 2014)

*Re: Warp9 or K10?*



MN Driver said:


> One thing I noticed when I was at EVCCON 2012 was that everyone who used a Warp motor who showed their Soliton settings or talked about them was that they were limiting their voltage in the 150-170 volt range. 170 volts is the max that Netgain recommends you run their motors, there are a few Youtube videos of 1000 amp runs on dynos where the commutator is arcing so running a higher voltage, I don't think should be paired with 1000 amps. I'm not certain of the limits for the Warp.
> 
> The Kostov K10 is different it uses interpoles so you don't need the brush advance to prevent arcing and the commutator won't get as hot. You are moving the critical hot area from the commutator, which is fragile under abuse, to the windings of the motor which can be better monitored with a thermistor(I wouldn't buy a Kostov without one, I bought my K9 HV with it installed, they bury it in the stator for you which is hard to do as an afterthought, it's a dirt cheap option that I think nobody should go without). The Kostov K10 is 144v nominal, not max. For example the K9 HV is 220v nominal in its high voltage winding setup but you can push 270v through it under overload(higher than nominal amperage), just pay attention to motorspeed so you don't blow past the 7000RPM maximum rated speed on the 9" Kostov.
> 
> ...


you answer is like a beam of sunlight after the rain for me. Thanks


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