Sabvoton not outputting full power even when set to

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cg_ebiker   100 mW

100 mW
Posts: 42
Joined: Mar 28 2020 11:58am

Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 01 2021 3:34pm

Ok, got a strange issue here.

I've gained a few months experience with Sabvoton controllers whilst building my current ebike (8kw enduro style) and taking it out down the road on test rides. Long story short, my first SVMC72150 died because of my stupidity with the phase wiring but I now have a new SVMC72150 which I would expect to work exactly the same way. On my first controller, I set the DC current to 85A and the phase to 160 which gave just under 5kw with my 52v battery. I confirmed this with the reading from my bluetooth BMS. There was one occasion where I tried a different throttle and the power seemed limited, with exactly the same settings I was only getting just over 3kw of power draw - weird! I checked the voltage output of the throttle and the settings on the sabvoton and there were no issues. As soon as I switched back to my normal throttle, bam - full power again.

I'm having a similar issue with reduced power with my new controller now. I have attached screenshots of my settings incase there is some glaring error which I can't find btw. I set the DC current to 85A, but the BMS only measures 60 and it feels nowhere near as quick as it did before. The thing is that if I increase or decrease the DC current, the bike gets quicker and slower and BMS reads more and less, but it' still drawing way under what it should be. I have tried shorting the throttle wire to 5v which should simulate full throttle but still same issue.

The best way I can describe it is it starts off normally for the first second (increasing phase current also makes a difference, but only for first second of accelerating) then just seems to gradually get up to speed whereas before, it felt like it had some poke to it. As I said, changing the setting does have an effect, but not proportional. Any ideas or experiences like this?

Cheers
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Jonno   100 W

100 W
Posts: 236
Joined: Sep 30 2016 6:41am
Location: UK

Re: Sabvoton not outputting full power even when set to

Post by Jonno » Jun 02 2021 1:01am

Do a new hall test

Jonno
Modified EEB frame, 888 forks, 280mm DNM pit bike shock, QS273 40h V3 3.5t, Nucular Electronics 24F controller 350a, 92V @ 36ah 26650 cells, 300a BMS with bypass,
Hope V4 + Galfer 223mm discs + Variable regen braking. PWM fan cooling.
.......and some other QS205 & QS273 bikes :confused:

cg_ebiker   100 mW

100 mW
Posts: 42
Joined: Mar 28 2020 11:58am

Re: Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 02 2021 3:52am

I redid it and got 192. Before however, I had around 170 or so and have even got 5 when running the test before so not sure what's going on there!

Would it work to manually put in whatever my previous value was if I can find it?

Jonno   100 W

100 W
Posts: 236
Joined: Sep 30 2016 6:41am
Location: UK

Re: Sabvoton not outputting full power even when set to

Post by Jonno » Jun 02 2021 4:27am

Try lowering the current limiting voltage and lack voltage by 5v as well

Jonno
Modified EEB frame, 888 forks, 280mm DNM pit bike shock, QS273 40h V3 3.5t, Nucular Electronics 24F controller 350a, 92V @ 36ah 26650 cells, 300a BMS with bypass,
Hope V4 + Galfer 223mm discs + Variable regen braking. PWM fan cooling.
.......and some other QS205 & QS273 bikes :confused:

cg_ebiker   100 mW

100 mW
Posts: 42
Joined: Mar 28 2020 11:58am

Re: Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 02 2021 3:05pm

I set them both to 0v, tried both throttles and still no luck. I'm really scratching my head as I can't think what it could be.

Only things I can think of are:
1. Bad hall test reading - if I can find my previous value, would it cause any dammage putting this in to try it out?
2. Faulty sabvoton - Surely it would either work fine or not work at all?
3. 2 faulty throttles - Unlikely as I tried shorting to 5v and same result.

Unfortunately I don't have any other sabvotons or motors to test :(
Help!!

cg_ebiker   100 mW

100 mW
Posts: 42
Joined: Mar 28 2020 11:58am

Re: Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 03 2021 2:10pm

I tried the previous value of 167, and no luck. The motor still spun but still only 60A of current.

I also downloaded an older version of the software that has more options for current limiting as I heard someone else solved a simialr issue through that but that didn't help unfortunately.

I feel like it's a really simple issue that I can't see as I'm 99% sure I've had this controller draw the correct amount of power before. There must be someone who can spot my mistake!

I've included the latest screenshots from the software.
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Mlubbock   1 µW

1 µW
Posts: 4
Joined: Aug 09 2019 12:55am

Re: Sabvoton not outputting full power even when set to

Post by Mlubbock » Jun 04 2021 1:12am

Hi CG,
It seems the root cause lies with your different throttles(?)
If so, firstly, would it be worth or possible for you to measure the resistance between the wiper and pot low and at pot high and make the comparison to see if the resistances are similar?
Secondly, given your settings for the first throttle is 1.3v 2.3v & 4.3v is it possible for you to measure the voltage (all in-situ) and alter your settings to suit?
Not sure why there is a mid-voltage setting - possibly for non-linearities?
Myles

cg_ebiker   100 mW

100 mW
Posts: 42
Joined: Mar 28 2020 11:58am

Re: Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 04 2021 2:49am

Hi Myles,

The cheap throttles I have use hall sensors not potentiometers so I can only measure the output voltage, not the resistance. I'll try measuring the output with my meter and see if there's anything weird there, but I have a new throttle on the way today to see if that fixes it. It seems the most logical solution but the app clearly shows 4.55v input with the throttle at max, but as I said I've had a similar issue before that didn't make any sense and turned out to be the throttle!

I'll get back once the throttle arrives

Mlubbock   1 µW

1 µW
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Joined: Aug 09 2019 12:55am

Re: Sabvoton not outputting full power even when set to

Post by Mlubbock » Jun 04 2021 10:07am

Cg,
Correct me if I’m wrong but I think the Sabvoton is looking for a throttle voltage signal from a potentiometer not a series of blips from a hall sensor???

At max resistance you’ll have close to zero volts and at min resistance you’ll have close to 5 volts? That seems to be confirmed by your parameter settings.

Hall sensors are used in the motor speed sensor and the PAS sensor but I’m pretty sure the throttle should be a simple pot? Is this possibly your issue?

Myles

cg_ebiker   100 mW

100 mW
Posts: 42
Joined: Mar 28 2020 11:58am

Re: Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 04 2021 10:37am

There are two types of hall sensors, analogue and digital. The digital ones are in the motor to provide blips but the analogue ones provide a variable output for the throttle. I believe potentiometers are used in higher end throttles but as I said, I've had hall sensor throttles working before. My new throttle has arrived so I will try that out shortly

cg_ebiker   100 mW

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Joined: Mar 28 2020 11:58am

Re: Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 04 2021 2:09pm

I tried out the new throttle today, and no difference immediately so I can rule that one out. On the ride however, decided to muck around with the controller temp limits by setting them well over 100. I don't know if this was luck or what, but suddenly I had a lot more power. There's still something wrong as when dc amps are set to 110A, BMS only reads 97 and at 150A set, only 133 so there is a 22% difference. I know the issue isn't the BMS reading as before I was pulling 85A with 85A set.

This is beginning to feel like a software bug as changing the current to 150A before increasing the temp limit had no effect, but after was giving me 133A? Also I decrease the phase current then increase it again, but it doesn't feel like there's a difference.

Of course it could be a faulty product, but weird how the issue suddenly developed? I've only had it for a few months and barely used it

Latest settings pics attached incase anyone can spot issues
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Mlubbock   1 µW

1 µW
Posts: 4
Joined: Aug 09 2019 12:55am

Re: Sabvoton not outputting full power even when set to

Post by Mlubbock » Jun 05 2021 1:21am

Cg,
I think there’s some potential to tune the motor temperature and current limits. I think,
Unwork should be top temp - perhaps 100C (Stops)
Rework gives you the hysteresis- perhaps 70C (restarts)
Limit current perhaps 60C (reduces current)
???
You could try disabling the motor temp sensor feature - with some degree of risk.
Perhaps also check the temp sensor wiring is sound.
Myles

cg_ebiker   100 mW

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Re: Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 06 2021 6:55am

Well I don't actually have the motor sensor wired up and the setting is disabled so that shouldn't cause an issue. I might as well try it for good measure though :)

Mlubbock   1 µW

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Joined: Aug 09 2019 12:55am

Re: Sabvoton not outputting full power even when set to

Post by Mlubbock » Jun 07 2021 3:53am

Now you come to mention it. My brand new SVMC72100 doesn’t have the white temperature wire in the motor multi plug. According to the MQCON wiring diagram it should (that’s potentially a problem for me).
Perhaps the temperature control is now only monitored within the controller (?)

Audisport09   10 W

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Re: Sabvoton not outputting full power even when set to

Post by Audisport09 » Jun 08 2021 5:55am

I have also played around with different throttles and noticed some throttles give more starting punch. Some are easier to control than others. Which ones are you using? Maybe it's the way the controller is reading the ramp up of the throttles. Have you tried Lowering the max and min throttle voltages to make them more aggressive to draw more amps? Have you tried to increase the ''Limit dc current'' to max battery amps? How do you know that you are requesting 85a of power? Maybe try to max out the controller settings and see how much it draws full throttle up hill until bms cut. Better yet, increase your voltage if you can.

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E-HP   100 MW

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Re: Sabvoton not outputting full power even when set to

Post by E-HP » Jun 08 2021 9:56am

cg_ebiker wrote:
Jun 04 2021 2:09pm
Latest settings pics attached incase anyone can spot issues
I'd start over with the throttle settings. Have you tried setting the throttle middle voltage to halfway between the min and max (2.825v based on you min and max values)? Also, the max phase current is more than three times the dc current limits, so seems too high. If you lower it to ~300A, then the throttle middle phase current of 150A will be half of that value.

cg_ebiker   100 mW

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Re: Sabvoton not outputting full power even when set to

Post by cg_ebiker » Jun 09 2021 12:54pm

I'll try these suggestions at the weekend but I've already maxed out the current settings and was only drawing 133A not the full 150. As I have no way of measuring the phase amps I can't verify that but didn't feel like it was giving everything. I also contacted the seller and they've sent me a different version of the software incase its a compatibility issue.

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