Tech Info: DC Motor Controller Shootout (144V+)
23rd September 2009
Note: 2011 update added at the end
We've had first-hand experience with almost all of the DC motor controllers currently on the market. Buying a controller for your EV is a big investment and the marketplace can be a bit daunting for new players because every product has its good and bad points. We hope this report will help you identify the most appropriate product for your vehicle.
Comments are summarised from owners of products and are not necessarily our own (though we generally agree). Manufacturers, you're welcome to contact us if you believe any statements are erroneous, and we'd love to hear if you believe you have addressed any prior shortcomings. And we're always interested to hear from any new manufacturers.
Controllers not available in Australia are listed in US dollars. Generally add about 50% when converting to Australian dollar cost to allow for exchange rate, shipping, customs costs and GST.
- Website: http://www.curtisinst.com/
- Power rating: 144V 500A
- Price: Around AU$2500
- The good: Quality, robust construction and proven reliablity
- The bad: 1.5kHz whine at low throttle (#1 complaint we hear), no configurability, not compatible with very large motors (11"+), expensive for what you get
Comments: The Curtis 1231C has been on the market, relatively unchanged, for a couple of decades now. It has by far the most well established reputation for reliability, though is looking a little underfeatured compared to the latest crop of controllers, and the audible "whine" at low throttle settings is a common complaint. (You can hear it in this video for example.)
Kelly Controller KDHB series
- Website: http://www.kellycontroller.com/
- Power: Up to 144V 800A or 156V 650A
- Price: Up to US$1500
- The good: Modern design with great feature set, wide range of models available
- The bad: Qualitatively underpowered (rated currents seem about 50% higher than reality - #1 complaint we hear), casing has small thermal mass, throttle/power wiring is a little awkward
- Website: http://www.logisystemscontrollers.com/
- Power: Up to 156V 1000A
- Price: Up to US$1800
- The good: Good range of models available, fairly high power ratings
- The bad: Clunky start (impossible to start smoothly - #1 complaint we hear, use of logarithmic throttle ameliorates this issue), ineffective heatsink, relatively small feature set and configurability
Comments: Also sold by NetGain as their "WarpCore" controllers (red casings).
- Website: http://www.cafeelectric.com/
- Power: From 156V 1000A to 350V 2000A
- Price: ~AU$2900 - $5000
- The good: High power ratings, good feature set, excellent reputation for quality & reliability.
- The bad: Installation is a little more complex, not waterproof, no low-end models available
Comments: Covers the high end of the market. Arguably overkill for commuter vehicles. Water cooled, so good for sustained high power but needs external water pump, radiator, piping, etc.
Synkromotive (Coming soon)
- Website: http://www.synkromotive.com/
- Power: 156V 700A
- Price: US$1600
- The good: Excellent feature set, fan forced ducted cooling should offer high continuous power
- The bad: Not actually available yet so no reputation, unconfirmed performance.
Comments: Due for release in late 2009, we have ordered one for testing as soon as they become available. On paper they look very promising but we'll reserve judgement until we get a chance to test one first-hand.
Conclusion (As of Sept 09):
For a while now it has been difficult to unequivocally recommend any 144V+ DC motor controllers on the market, as there seems to be no perfect solution available. If you can afford a CafeElectric Zilla, you won't be disappointed, but they are admittedly at the high end of the market. We also have high hopes for the Synkromotive controller based on its datasheet and our communications with the designer/manufacturer, but recommend people wait to hear independent reports on performance before ordering.
Since this report was originally compiled, a couple of new options have hit the market (including ZEVA's own controller).
- Website: http://www.zeva.com.au
- Power rating: 144V 600A
- Price: AU$1450
- The good: Good value for the power, quality construction, Australian made
- The bad: Modest power rating & featureset, relatively low thermal inertia of case
Comments: ZEVA's own motor controller, designed as a low-cost option to Curtis/Kelly/Logisystems for small vehicles (around 1 tonne) where a Zilla/Soliton is overkill. So far the controller has been well received and with minimal faults.
EVnetics Soliton 1 & Jr
- Website: http://www.evnetics.com
- Power: 300V 1000A (S1) or 300V 600A (SJr)
- Price: AU$3200 (S1) or AU$2300 (SJr)
- The good: Robust and weatherproof housing, convection and water cooling supported, good feature set, high sustained power, internal contactor with precharger
- The bad: Physically large & heavy, relatively pricey
Comments: EVnetics' Soliton controllers may be the most professionally constructed DC motor controller on the market. They offer excellent performance, smooth power delivery, and programmability over ethernet. Highly recommended, if they're within your budget.