Sabvoton SVMC072150 controller review, variable regen *PICS*

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Sabvoton SVMC072150 controller review, variable regen *PICS*

Post by zombiess » Aug 07 2014 1:17am

Full disclosure, I will be selling these units because I like them. I will start a separate thread in the appropriate for sale section, so please keep that discussion in that thread.

A few months ago I picked up a SVMC072150 from Sabvoton to review and have had it on my bike for about 2 months while I've been testing it. Since I no longer modify the Xie Chang controllers and often have people asking me what controller they should use with a Cromotor, I set out to find a good compromise between performance and cost because I had a goal of selling a cycle analyst compatible controller kit for the Cromotor for <$500 including wiring, fuse, power wiring and the throttles/buttons.

I wasn't to sure about the different specs until I emailed the company and spoke with them by email a bit, 6kW is a good rating, but I was quite excited when I found out that was a continuous rating and the burst rating was 12kW. Once I received the controller with blue tooth wireless I hooked it up to a 75V 18S3P LiPo pack.

The controller has some built in protection and uses 24 IRFB4110 MOSFETs which means one shouldn't run a fully charged pack of higher than about 85V. It's a sine wave based controller with phase current control. It will do 12KW bursts for 3 mins or until something reaches the over temperature setting. The maximum battery current is 150A and I was able to reach that during acceleration with my Cromotor in a 25" tire setup. It is rated for 6KW continuous at 72V so around 85A battery. It has built in protections for battery current and phase current. Each one has a maximum setting and a normal working setting. The maximum setting is what it will burst to and the normal setting is what the currents will go to if it's above them for 3 mins.

It has several really nice features that higher end controllers do.

Protection - Over temperature, over voltage, under voltage, phase current, battery current.

Regen - It has 2 types of regen, slide regen and normal button regen activated by sending a +5v signal to the regen wire. Both as set in phse amps and can provide a strong regen force, enough to cause the rear 19x"3.0 Shinko SR244 tire to be on the verge of skidding while it's engaged at any speed over 20mph.

Setup - The hall sensor setup had an automatic learning feature which made getting the hall phase combination a very easy process, took about 1 min to learn after I figured out the correct sequence in the software I needed to get it to learn the combination. It came with instructions, but they need to be clarified a bit.

Field weakening. I believe it's settable from 0-100A. I need to do some more testing on how much it effects my top speed but I think I saw 53mph with it set to 50A, but I can't remember for sure so I'll have to go test again after I recharge the battery. Nice thing with field weakening is that it only decreases the efficiency when it's in use, which is usually only when you make those short high speed sprints, not at normal cruising speed.

Phase current control based throttle - This makes riding very nice. It has a variable up/down time limit settable in milliseconds to help buffer out any throttle jolts that happen while riding. The throttle voltage end points are adjustable so it will match any pot type throttle or hall based throttle and provide full range. The throttle mid point and also the phase current mid points are adjustable so that you can customize the throttle curve.

Real world use - I set it up to allow 150A battery, 350A phase and turned on slide recharge mode to 75A. This is a pretty typical setup I use to thermally load a controller while I proceed to ride around like an idiot doing 0-top speed back to 0 mph using regen as many times as I can until the controller gets too hot. The controller never got hot, but my motor and wiring weren't too happy so I only got about 5 mins of testing and was concerned about the motor and phase wires. Highest temp I saw was under 40c and it started off at 25c on a 25c day. I need to test this some more, but it's not really too surprising since the Cromotor doesn't pull high amps for very long on level ground and the internal heat sinking is large with the MOSFETs mounted flat on a large 0.25" base plate which is then mounted to the aluminum case.

Bluetooth - cool when it works, but the android application seemed to crash a lot and had many connection issues. Was good for quick monitoring of the controller temperature while abusing it, but unstable. I'm skipping this feature for right now until the application is more stable.

So after I tried out the controller for a few weeks I decided that I wanted to sell them, but I wanted some additional features. I saw that the software had a display for motor temperature, but I didn't see any settings for it. There are settings for over temperature of the controller, but no motor temp.

I contacted Sabvoton again and asked them if they were interested in adding features to their controller and having someone in the US selling them. They offered to add the features I thought people would really like to see in a high power controller. Because I'm planning to offer these with the motors I sell, I asked them to add support for a 10k NTC temperature sensor. The other feature I thought people would really like is a second throttle input that does variable regen. They agreed to add these features and I have been testing them for the last 1.5 weeks since I received a batch of their controllers. The variable regen works very well from 0 to almost locking up the rear tire if you set it high enough. It's only enabled when you activate the brake switch. This allows you to use a low level slip charge for normal riding which I've found greatly improves my regen, but when you press the brake button you can coast like normal, or vary the amount of stopping force that regen is providing :)

The hardware works great, but they need to update the software to allow more flexibility in the variable regen and motor temperature protection settings. I just emailed them tonight and let them know the variable regen works as expected and suggested some improvements to the programming software. The software has not been updated to handle these new features since they only developed them last month at my personal request which was very awesome of them to do.

Pros - cool features, affordable, high power, phase current control, protection, variable regen, virtually silent (my freewheel is much louder than the motor)
Cons - largish, about the same as a 24 FET Xie Chang / Lyen, I'll post up some pics for comparison, buggy android software, programming software is a little clunky, but works well.

Review is a bit biased due to my personal interest in these, but I'm trying to be realistic and represent it accurately which is why I mentioned the issues I saw (and will work with them to improve).

Here are some pictures to get a good idea of it's physical size. It's very similar to a Xie Chang 24 FET, but it's much heavier and the quality of construction is vastly superior.
Sab-vs-XC-24-01.jpg
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Sab-vs-XC-24-04.jpg
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Sab-vs-XC-24-05.jpg
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This is the inside of a 24 FET Xie Chang controller
Sab-vs-XC-24-06.jpg
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This is the inside of the Sabvoton
Sab-vs-XC-24-07.jpg
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MOSFETs are mounted flat to a large heat spreader plate
Sab-vs-XC-24-08.jpg
Sab-vs-XC-24-08.jpg (67.83 KiB) Viewed 11867 times
Last edited by zombiess on Aug 11 2014 1:50am, edited 3 times in total.

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by kenkad » Aug 07 2014 7:02am

Since you have a close relationship with Sabvoton and you mention two types of regen, maybe you can clarify how they do their regen. In particular, do they actually modulate the lower bridge to control the voltage going back to the battery or do they have some type of boost circuit for the regen. Thanks for asking this question.
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Re: Sabvoton SVMC072150 controller review, variable regen

Post by Futterama » Aug 07 2014 7:12am

Great review, looking forward to see some pictures 8)

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by ambroseliao » Aug 07 2014 7:40am

How much did it cost including shipping?
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Re: Sabvoton SVMC072150 controller review, variable regen

Post by spinningmagnets » Aug 07 2014 8:23am

I will be curious to see your results on harvested regen to the battery.

Regen will continue to be debated, but the using regen as the most commonly used brake is a wonderful feature, IMHO. Using regen keeps the disc brakes cool, so that when you actually need them, they will be working at full capacity.

That being said, I feel the harvested battery watts is clearly a secondary benefit. But...no matter how small, free watts to add to the bikes range is still free watts. The worst case regen set-up is a light bike with a light rider, on skinny tires, using low-current batteries. The driven tire will easily lock up in that situation (weight shifts forward on downhill braking, rear hub on skinny tire).

Cromotor bikes are not light, they use high-current batteries, and they have fat tires with a large contact patch for good traction during deceleration. This has got to be the optimum set-up for harvesting regen (even if that is not its primary use in this user profile).

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by Bluefang » Aug 07 2014 9:15am

Can you compare the start up torque to a kelly controller at all? I have a pair of kelly controllers on my motorbike that are around that same power level but absolutely suck at start up torque due to a non programmable current safety limit. I have set everything to max and it cuts out if i pull the throttle too much.

Can the sabvoton controllers provide enough burst current to lift the front wheel to really push you back without cutting out etc? Is the burst current capability comparable to a Xie Chang?
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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 07 2014 11:30am

Bluefang wrote:Can you compare the start up torque to a kelly controller at all? I have a pair of kelly controllers on my motorbike that are around that same power level but absolutely suck at start up torque due to a non programmable current safety limit. I have set everything to max and it cuts out if i pull the throttle too much.

Can the sabvoton controllers provide enough burst current to lift the front wheel to really push you back without cutting out etc? Is the burst current capability comparable to a Xie Chang?
Startup current is good. It feels exactly the same to me as a large Xie Chang 24 or 36 FET controller pulling the same battery amps. On a normal wheel base bike it will flip you right over if you grab a bunch of throttle.

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 07 2014 11:32am

ambroseliao wrote:How much did it cost including shipping?
I think with shipping and wire transfer fees it was about $425

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by ambroseliao » Aug 07 2014 11:44am

Thanks Z. How would you compare it to the Adaptto system?
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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 07 2014 1:17pm

ambroseliao wrote:Thanks Z. How would you compare it to the Adaptto system?
I haven't tried it. Physically this controller is larger and should have a higher continuous wattage rating based on construction, but burst current wise both seem to be the same 12kW which means performance will be about the same for acceleration/wheelies etc, what most people want. Ebikes tend to be an easy load to drive because the motors are usually high inductance and only take high current bursts for a few seconds before they settle down to low current levels. You get more features with the Adappto, but that's reflected in the pricing. I have a customer who uses Cromotors as mid drives in a +3000lb vehicle so it's hard on controllers. They even managed to get one road legal by sustaining >20mph for over 1 mile. For commercial use I need a high quality controller than what the Xie Chang was providing and 8-12kw bursts make for a really fun bike.

I evaluated on contruction, pricing and feature set, ended up choosing this controller. I would really like to get this company or Adappto to use a power stage setup I've designed so I can start selling high power controllers. I have the gate drive/power stage figured out, but don't have my own controller brain and don't desire to design my own at this point.

I've chosen to use Lebowski's brain for my own personal controller development as I have direct access to him and he implements suggestions, he's also working on new control techniques and I support that as a lot of work I'm testing out is not mainstream... yet. I'd like to see his controller brain go into a commercial product in the near future, it's getting pretty good and more user friendly. I am continuing the development work on my own controllers based off his chip to handle high current (500A range).

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 07 2014 1:31pm

spinningmagnets wrote:I will be curious to see your results on harvested regen to the battery.

Regen will continue to be debated, but the using regen as the most commonly used brake is a wonderful feature, IMHO.

I use regen as a brake more than I care about recovered energy which is why I wanted variable regen. I have found that I consistently get much higher regen percentage using slip/slide charge mode, even if it's at a low setting. With it being variable you can coast or brake, best of both worlds. I'm going to trigger it to engage the 2nd throttle off of the ebrake switch in my Hydraulic Tektro brakes so all I need to do is lightly grab the front/rear brake lever and then twist a left hand throttle to vary how much I slow down. If I need hard braking, that's what the mechanical brakes do.

Car manufacturers utilize regen while coasting because most people don't use pulse/glide in a car. I don't use it on a bicycle either. Tried both ways, button regen and slide regen. Using a button I only recovered about 3% vs 10-12% on the same commute using slip charge. This test was done a wile ago when I was still commuting by bike, but I still find those numbers to hold about the same when I go even for a low speed ride with my wife.

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by heathyoung » Aug 07 2014 6:45pm

Are they available in higher voltages (eg. 150-200V?)
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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 07 2014 9:24pm

heathyoung wrote:Are they available in higher voltages (eg. 150-200V?)
Nope.

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by Merlin » Aug 08 2014 7:37am

theres no need for 150-200v i think (because the flux weakin / FOC will give you more Topspeed as you can handle.)

but theres a 96v Version you can buy in a few weeks.
So you can go up to 120v (Safe) or 125v (30s Lipo) on your own risk....but really..... No one needs 30s with FOC.
(But a "Little" Problem will be the Size of the new Generation....64 * 165 * 185mm)
They like to go with the sizes of Sevcon and Golden Motors. WE eBikers are just a small batch and atm not worth to change the design ;)
Maybe Zombie can order a small batch for Ebikers (rated 6KW continue with half of the size :P)

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by ARod1993 » Aug 08 2014 8:24am

zombiess wrote:
heathyoung wrote:Are they available in higher voltages (eg. 150-200V?)
Nope.
That said, how feasible would it be for an end user to provide FET/Cap Replacement Therapy for one of these things to get it to run with 24s-30s LiPo?

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by MitchJi » Aug 08 2014 10:12am

Hi,

Will they run the small Colossus?

Sensorless (Astro or small Colossus)?
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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 08 2014 11:36am

This is controller is engineered pretty well. Replacing components and hacking it apart seems like a waste of time to me. It is easier to design a controller based on lebowskis chip.

Not sure why one needs 100v on a high powered Ebike. It's rare to go over 50mph in real life for more than a min. If constant high speed is required then one is building a MC and will be using a larger motor and controller than this. I am able to exceed 50mph on a 75v 18s lipo pack with a 25" tire.

Controller requires hall sensors. As far as I know there is no such motor as a small Colossus yet. There are large Colossus motors coming in about 60 days.

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by amberwolf » Aug 08 2014 1:24pm

The reason for higher voltage that I'd use it for is to reduce currents (and wire sizes / resistive heating, possibly inductive effects) to get the same wattage out of a system, same speed, just geared or wound differently. Also less load on the batteries, can use lower C-rate (probably cheaper) cells (though it requires more of them in series, of course).

Also having a controller that's got components rated for the higher voltage means less likely to have random failures from spikes/RF noise than otherwise, though those shouldn't happen if it is well-designed in the first place. ;)

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 08 2014 3:36pm

Amberwolf, some of those are good reasons, but they don't really apply to what this controller is designed for, medium power hub motors.

The slow wind hub motors tend to be low power. I've found that 8 gauge wiring has worked fine at the power levels I run because the load is not continuous. At > 100A continuous 4 gauge or higher is required. With higher voltage comes the dangers associated with it. I sometimes run 125V packs when testing, but one has to treat it with caution.

The slow wind motors are saturated at low amps. Remember that I'm pairing this controller for use with a Cromotor since I am always asked by customers what controller I recommend.

Batteries are subject to the same stresses because it's based on power. 1000v @ 1a or 1v@1000a is the same amount of power. Both are petty extreme cases for a motor drive and both are difficult to design for. The solution is to pick a point in between to get 1000w. What one chooses to go with is usually dictated by application limitations.

For Ebikes and light motorcycles working in the 50 to 150v range makes the most sense. Over 50v one has to past close attention to what they are doing. If I had a 350v pack in use I probably wouldn't be typing this right now because I have made mistakes and come into contact with pack voltage as have most people on this site and in not just talking kff. At 350v a kff could easily turn into a finger exploding.

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 10 2014 12:28am

I forgot to mention that during my testing, I left the controller hooked up to a battery for 1 month without using it. The battery voltage stayed the same 67.8v so there is no aprecciable current draw if it's left connected.

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by John in CR » Aug 10 2014 4:03am

zombiess wrote:I forgot to mention that during my testing, I left the controller hooked up to a battery for 1 month without using it. The battery voltage stayed the same 67.8v so there is no aprecciable current draw if it's left connected.
That's good...none of that what I consider silly and problematic drain down resistor stuff. How many packs have been killed due to that tiny resistor?

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by Futterama » Aug 10 2014 8:07am

amberwolf wrote:Also less load on the batteries, can use lower C-rate (probably cheaper) cells (though it requires more of them in series, of course).
zombiess wrote:Batteries are subject to the same stresses because it's based on power. 1000v @ 1a or 1v@1000a is the same amount of power.
zombiess, when voltage goes up (more battery cells) current goes down for the same amount of power, and it is the current that stresses batteries, so the batteries are not subjected to the same stresses as you wrote.

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by heathyoung » Aug 10 2014 7:00pm

Its not for an ebike :)

At 80Kph @ 150V considerable field weakening will be necessary to push past 100Kph I would think.

120V may be usable - not sure.
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Re: Sabvoton SVMC072150 controller review, variable regen

Post by sn0wchyld » Aug 10 2014 7:58pm

Futterama wrote:
amberwolf wrote:Also less load on the batteries, can use lower C-rate (probably cheaper) cells (though it requires more of them in series, of course).
zombiess wrote:Batteries are subject to the same stresses because it's based on power. 1000v @ 1a or 1v@1000a is the same amount of power.
zombiess, when voltage goes up (more battery cells) current goes down for the same amount of power, and it is the current that stresses batteries, so the batteries are not subjected to the same stresses as you wrote.
His point is that for a given size battery (wh), 1kw draw is 1kw, and stresses the pack the same be it a 100v pack or 10v pack. Aw is talking about adding cells to the pack though.

That said, i too would like to know if it can be hacked/made for 30-32s capable, as im building a mid drive, so i want to spin the motor fast, for efficirncy both of motor and controler, particually at low speeds. I dont so much want high top speeds, but efficient, high power from 5-60ishkm without worrying bout controller or motor. A 4115 or equivilant version wold have me(and a few others i imagine) lining up. Ive been chasing the russians to see if they can produce a hv version of theirs too, but getting a respone from them is kinda hit and miss........

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Re: Sabvoton SVMC072150 controller review, variable regen

Post by zombiess » Aug 11 2014 12:50am

sn0wchyld wrote:
That said, i too would like to know if it can be hacked/made for 30-32s capable, as im building a mid drive, so i want to spin the motor fast, for efficirncy both of motor and controler, particually at low speeds.
I don't understand your logic with this. How does high voltage = good efficiency? Efficiency is based on the overall system not just a single component. I know it's more efficient to transmit power at high voltage over long distances due to resistance, but that's not a problem in EV setups.
I dont so much want high top speeds, but efficient, high power from 5-60ishkm without worrying bout controller or motor. A 4115 or equivilant version wold have me(and a few others i imagine) lining up. Ive been chasing the russians to see if they can produce a hv version of theirs too, but getting a respone from them is kinda hit and miss........
If you don't want high top speeds, but you want high voltage, what are you doing? Every reduction gear stage robs you of several percent efficiency. For a mid drive it's most efficient with just 1 stage, chain to drive gear. If you don't need high speed, then you don't need high voltage, you need a motor that has the correct KV. For that matter if you did want high speed you could do it with low voltage, it would just require more amps.

Don't forget that motors with more turns per tooth saturate at a lower amperage point than a motor with fewer turns. Once the motor is saturated efficiency goes way down. It's a balancing act of choosing the right components for a job. If I used a normal 9.3KV Cromotor in a 1:1 mid drive setup to go 40mph, I would need about 75V @ 60A to hold that speed. If the motor saturates at 200a then I can't ever get more than 15kw out of it. If I switched to my special 18KV Cromotor I could obtain 40mph with 38V @ 120A. If I used a 2:1 reduction then I could use 75V @ 60A to go 40mph again. Because this motor has half the turns, it would saturate at 2x the normal motor meaning I could run 75V@400A and obtain 30kw before saturation.

This controller is not easily hackable for higher voltage from what I've seen, but that doesn't mean it's not possible. It's much much more complex than a Xie Chang controller is and there is a large difference in how it rides and the features it has. Best part is it's only about $100 additional and more reliable since it was designed to run up to 12kW for a few minutes.
Last edited by zombiess on Aug 11 2014 1:34am, edited 2 times in total.

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