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__Tango
03 December 2013, 1721
Quick question, what is the absolute max battery voltage for a Curtis 1238-7501 or 1238-7601? The docs say nominal voltage 72-96V, but what's the absolute max?

podolefsky
03 December 2013, 1837
130V

frodus
03 December 2013, 1952
Just careful if it's that high and regen gets disabled.... You won't have the regen you're expecting. They say 36s of lifepo4 is the highest they'd go.

__Tango
03 December 2013, 2250
K. Just doing some pie-in-the-sky dreaming. :)

glassblower
04 December 2013, 1337
You thinking about changing out that Sevcon with a Curtis on the hub motor?

__Tango
04 December 2013, 1422
The curtis is only an AC induction controller, so i'm possibly thinking about doing another build with an AC system (or swapping out the hub motor on my current bike). I don't have time to do this mind you, but it's always nice to dream. :)

Athlon
04 December 2013, 1645
If you need higher voltge there is the 1239E-85xx with nominal voltage 72–144 , absolute maximum voltage of 170V.


BTW all the 1239 curtis controller are also optoisolated ( logic is optoisolated form traction voltages)




1239E-65xx 1239E-76xx 1239E-85xx
Nominal high power battery voltage (V) 60–84 72–108 72–144
B+ maximum voltage (V) 105 120 170
Maximum current (A rms) 550 650 500
S2–60 minute current (A rms) 155 200 135
Continuous current for design life (A rms) 175 200 170

__Tango
04 December 2013, 1851
(Athlon, use "CODE" formatting for tables...)





1239E-65xx 1239E-76xx 1239E-85xx
Nominal high power battery voltage (V) 6084 72108 72144
B+ maximum voltage (V) 105 120 170
Maximum current (A rms) 550 650 500
S260 minute current (A rms) 155 200 135
Continuous current for design life (A rms) 175 200 170


A couple of months ago (before the 1239 was available), I asked the HPEVS folks about using "the new curtis 144V controller" with an AC-20 motor. They said since it wasn't optimized for such high voltages, it may not be as much of an improvement as you'd think. I'm not sure if this is still the case however.

podolefsky
04 December 2013, 2017
HPEVS has graphs for the AC-20 at 108 and 144V. Both peak out at about 73.5 HP. I thought maybe because the 1239 is 500A, vs 650A for the 1238. So you might expect them to be about the same.

But then you compare what happens with the AC-50. At 108V they get 76HP. AT 144V they get 87HP. Seems like the AC-50 uses the higher voltage better than the AC-20.

There's some funny stuff going on with voltage sag in the different graphs, but I think the main story is what HPEVS told Tango. At 144V, the AC-20 hits 73.5HP at 8000RPM, which is max RPM the controller will do. It runs out of RPM before it can take advantage of the full 144V.

The 144V graph (http://hpevs.com/Site/images/torque-curves/ac-20/144%20volt/Imperial%20pdf%20graphs/AC20%20144%20volt%20500%20amp/Peak%20graphs/ac-20%20144%20volts%20500%20amps%20imperial%20peak.pd f) show's what I mean.

__Tango
04 December 2013, 2246
Also, Athlon, where did you get that table of information?

__Tango
04 December 2013, 2357
Another thing, there is an AC23, which the site says:


The AC 23 motor is same size as its sister motor the AC-20, but has been developed to produce more torque. On the same voltage and amperage as above (96 volt/650 amps), this motor produces 128 ft./lbs. of torque and 56 horsepower out to 3300 RPM.

The graph for the AC23@144V/500A looks more like an AC20@108V/650A.

If i'm reading this right, running the AC23@144V/500A seems to get similar performance to the AC20@108V/650A. So possibly similar performance with less heat? That'd be good since the AC20s tend to run hot.

Here are the graphs:

AC23@144V/500A:
http://electriceptor.files.wordpress.com/2013/12/ac23-144v.png

AC20@108V/650A:
http://electriceptor.files.wordpress.com/2013/12/ac20-108v.png

Here's the AC20@144V/500A for reference:
http://electriceptor.files.wordpress.com/2013/12/ac20-144.png

podolefsky
05 December 2013, 0703
Interesting...so not an RPM limit. The 20 really has nothing more to give.

I don't think you'll get less heating. Luke explained this somewhere I can't find now. If you have the same motor with same amount of copper, even wound differently, higher voltage doesn't change I^2*R losses. For same power, you have lower I but higher R, so they cancel out.

Athlon
05 December 2013, 1755
Also, Athlon, where did you get that table of information?


Curtis 1239 manual

ARC EV Racing
08 December 2013, 1032
Give us a couple of months and we might be able to offer some data on how a pair of 1239 / AC23 perform

Sent from my AZ210A using Tapatalk

picaroon
08 December 2013, 1537
Give us a couple of months and we might be able to offer some data on how a pair of 1239 / AC23 perform


I've been checking your twitter posts to see how your latest race bike is coming along....... great to see those motors and controllers mounted together yesterday.
Your headstock is a work of art!!!

ARC EV Racing
09 December 2013, 0259
I've been checking your twitter posts to see how your latest race bike is coming along....... great to see those motors and controllers mounted together yesterday.
Your headstock is a work of art!!!

Thanks Pic, that headstock has been a labour of love for Brendan.
The 1239 controllers are nice, even easier to work with now that the logic is isolated from the power circuit.

Sent from my AZ210A using Tapatalk