# AC50 and medium sized cars

5588 Views 11 Replies 6 Participants Last post by  JRP3
The AC50 seems to have the highest profile of the AC Motors but I read varying anecdotal reports of its capability around hills. Chinese BLDC motors are looking very promising as an alternative.

On my commute I have a hill climb that has to happen. My car is a BMW 318ti. I am doing all my calculations at the GVMR 1555kg just in case.
The hill is a 4.6 degree angle (8 percent incline). I have calculated this to require 30-35Kw, and as it is 2km I will need to hold this for 90 seconds. If I do 1:1 through a transmission to the 4.44 diff then 3000 RPM will do 80km/h - sounds perfect. (Side question: I haven't decided whether to modify the auto transmission or put in a two speed transmission yet, but understand the former may add significant losses - any idea how bad?).

Either way, is this motor up to it? The chart says it can do over 40Kw at 3000 and at that point still has its 150 maximum torque.
http://hpevs.com/Site/images/jpeg/power-charts/pdf/ac50_102v_650a_metric.pdf

However people quote 50kw as its peak performance. So is this graph all peak readings? If so, how long is it reasonable to expect a motor to operate at peak for? And what if one added a water cooling plate to this motor (and to the controller), what impact would that have?

Richard
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Hi,

I've put your datas in my calculator, and made a simulation with :
- 32Sx3P Calb-SE100AHA (25kWh usable 91kW max)

The results on flat ground :
- 137 km/h max
- 87 km
- 283 Wh/km

With 8% grade :
- 80 km/h max
- 42 km
- 576 Wh/km

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Hi Kennybody, thanks for your comment. In fact, this is just a single simulator based on motion équation.

But it gives you the time to reach the speed. Here 6 mn with 8° grade.

If the AC50 can stay 6 mn at full power it's ok, otherwise you have to reduce power.

It'll take longer, at a reduced speed, but safer.

The important thing is you can run an 8° grade, with a 1555kg car equiped with an AC50, and with care, as with an ICE car.
Hello Richard, I've just upload the speadsheet with HPEVS AC motors.