Controller upgrade from Sabvoton 72150 recommendations.

[Cr1sp]

I have a Stealth Bomber clone that I built about 5 months ago which I'm generally happy with but there's two things that I'm not happy with; it doesn't wheelie under it's own power, I have to preload forks and lift the bike to get it to wheelie and I want slightly higher top speed without changing motor windings.

I'm using a Sabvoton 72150-M controller
QS 273 V3 5T motor
Battery Link: https://www.enduroebike.com/index.php?route=product/product&path=137_123&product_id=377
but the quick specs are: 20s14p Panasonic ncr18650GA rated for 150A continuous and 200A burst for 5 seconds.

I can get the bike to lift the front wheel about half an inch sometimes under its own power so that tells me that it's very close to being able to fully wheelie under its own power however my Sabvoton is locked and doesn't let me go higher than 150A on DC current same goes with flux weakening, it only allows me to enter 50A which only gets me extra 2MPH top speed from 40MPH to 42MPH, I would ideally want 50MPH but I would be happy with 47MPH or slightly under. I'm considering upgrading to Sabvoton 72200 as then I could set the boost current to 200A while keeping DC current at 150A which I believe the bike could then wheelie on it's own and I would get few more amps on flux weakening which would get higher top speed. I would ideally want to upgrade to an unlocked Sabvoton controller but all unlocked ones are non display versions and it appears all display ones are locked. I was considering Cycle Analyst with unlocked controller but being from UK, CA is not widely available, bit pricey and overkill for my use, all I need a display for is speedometer, power output and assist levels which UKC1 does just fine and UKC1 being cheap and widely available, if I crash my bike on a trail and break the display, it's not a problem getting another one and replacing it in matter of days.

I'm wondering if there's better alternatives to Sabvoton 72200 that are roughly same price £330 ($400 USD) with display compatibility? Thanks

 

[amberwolf]

I would ideally want to upgrade to an unlocked Sabvoton controller but all unlocked ones are non display versions and it appears all display ones are locked. I was considering Cycle Analyst with unlocked controller but being from UK, CA is not widely available, bit pricey and overkill for my use, all I need a display for is speedometer, power output and assist levels

You might already know this, but the CA doesn't actually talk to the controller, so if you need the output/assist changes to happen in the controller settings themselves, it can't do that for you.

It *can* still vary the assist level, and modulate the power the controller draws from the battery by modulating the throttle output to the controller based on watts monitored at the battery-side shunt, if that is sufficient for you. (t can also do a fair number of other things that the controller itself can't, but the controller can also do things the CA can't).

But as you note, it's harder to get (and probably significantly more expensive than the UKC1).

I don't know enough about them to help pick one, but there are people that have had good luck with the Fardriver controllers, such as in this thread:
https://endless-sphere.com/forums/viewtopic.php?f=30&t=112177
I *think* they use BT to an app for android rather than a dedicated display unit, but don't quote me on that.

Probably not the direction you'd like to go, but if you are willing to do some DIY, you can "build" (or perhaps modify) a controller based on one of the higher-power VESC projects here on ES (or elsewhere).

 

[amberwolf]

On the battery, how much voltage sag (drop in voltage from whatever it was without load) does it have when trying to wheelie, or under other high loads (like at full speed)?

Voltage sag robs the system of watts, and sometimes this can be the cause of problems at higher loading being unable to accomplish something a system can *almost* do.

 

[E-HP]

I'm using a Sabvoton 72150-M controller
QS 273 V3 5T motor
20s14p Panasonic ncr18650GA rated for 150A continuous and 200A burst for 5 seconds.

I can get the bike to lift the front wheel about half an inch sometimes under its own power so that tells me that it's very close to being able to fully wheelie under its own power however my Sabvoton is locked and doesn't let me go higher than 150A on DC current same goes with flux weakening
Thanks

I don’t think this is a power issue. It’s a power delivery issue. You should be able to get the bike to throw you on your back with even half that power is delivered off the line.
I see posts on this issue fairly frequently on the Sabvoton controllers, once or twice in the last couple of weeks, but haven’t followed them to conclusion, but it seems like adjusting settings might help. Phase current needs to be sufficiently high as well. You’d be disappointed if you got a bigger Sabvoton but still have the issue, so might be worth spending some time on tweaking.
You likely need higher voltage for the speed though if flux weakening is already turned up.

What are your settings on the throttle setup page (acceleration time, deceleration time)? That and the motor direction on the motor page?

 

[Cr1sp]

On the battery, how much voltage sag (drop in voltage from whatever it was without load) does it have when trying to wheelie, or under other high loads (like at full speed)?

Voltage sag robs the system of watts, and sometimes this can be the cause of problems at higher loading being unable to accomplish something a system can *almost* do.

With almost fully charged battery (83v), doing a full throttle pull from a stand still, the voltage drops to 74v-73v with a peak power output of 9200w (according to UKC1 so take this with a pinch of salt, the watt measurement might not be accurate). I remember working out the voltage sag of this battery pack using cell sheet before I bought it and remember getting something around 10v sag with 150A draw so 83v to 74v-73v does seem correct for these cells.

I'm using a Sabvoton 72150-M controller
QS 273 V3 5T motor
20s14p Panasonic ncr18650GA rated for 150A continuous and 200A burst for 5 seconds.

I can get the bike to lift the front wheel about half an inch sometimes under its own power so that tells me that it's very close to being able to fully wheelie under its own power however my Sabvoton is locked and doesn't let me go higher than 150A on DC current same goes with flux weakening
Thanks

I don’t think this is a power issue. It’s a power delivery issue. You should be able to get the bike to throw you on your back with even half that power is delivered off the line.
I see posts on this issue fairly frequently on the Sabvoton controllers, once or twice in the last couple of weeks, but haven’t followed them to conclusion, but it seems like adjusting settings might help. Phase current needs to be sufficiently high as well. You’d be disappointed if you got a bigger Sabvoton but still have the issue, so might be worth spending some time on tweaking.
You likely need higher voltage for the speed though if flux weakening is already turned up.

What are your settings on the throttle setup page (acceleration time, deceleration time)? That and the motor direction on the motor page?

Luckly because Sabvotons are not common in UK, used 72150's sell for the same price as brand new 72200 on AliExpress so if I did upgrade to 72200, I could sell my 72150 and make all of my money back effectively upgrading for free so I wouldn't be upset if that doesn't fix my issue however the Sabvoton does not fit in the stock stealth bomber clone controller box so I had to make a custom one, the 72200 is slightly longer so I would have to make a new controller box so I would have to spend a day making a new one. To me it doesn't make sense to potentially get my motor re-winded or upgrade to higher voltage just for extra 8mph however 72150 has a limit of 50A flux weaking while 72200 has 100A, the extra 50A will probably not get me to 50MPH but it will certainly get me closer.

This is my first bike that's above 2000w so I have nothing to compare it against so I'm not sure if there's an actual power problem or if my bike is fairy well balanced, keep in mind that the bike probably weighs about 220-200lb plus me which is another 170lb so it's a lot of weight, I'm also using motorcycle rims with heavy off road tyres, double crown fork and Honda Grom front headlight so there's a lot of weight up in front. I took screenshots of the relevant app settings, before anyone points it out, my max throttle voltage is set at 5v because when I fully twist the throttle, the app says it's at exactly 5v so that's not the issue. I did have it at 4.80 at one point and made the bike slower.

 

[Eastwood]

That’s your problem, your rated phase amps are way too low. Well, way too low for performance and power wheelies.

On my stealth bomber build I keep the rated phase amps 350 when I have the dc amps at 150. You’ll definitely loop out at those settings if you’re not careful.

For higher TopSpeed, have you tried the flux weakening? If not try 50 amps it’ll give you a few more miles per hour.

Also, something to consider you really don’t need a QS 273 when only running at 150 A. The QS205 can handle those power settings as long as you’re not ragging it out. Plus, it’s about 20 pounds lighter. Just something to consider for the future.

 

[Eastwood]

Also, reading about your voltage sag it seems that something might be off. It seems like you’re getting too much sag for those cells. Did you build the battery? This could also has something to do with acceleration/wheelies

 

[Cr1sp]

That’s your problem, your rated phase amps are way too low. Well, way too low for performance and power wheelies.

On my stealth bomber build I keep the rated phase amps 350 when I have the dc amps at 150. You’ll definitely loop out at those settings if you’re not careful.

For higher TopSpeed, have you tried the flux weakening? If not try 50 amps it’ll give you a few more miles per hour.

Also, something to consider you really don’t need a QS 273 when only running at 150 A. The QS205 can handle those power settings as long as you’re not ragging it out. Plus, it’s about 20 pounds lighter. Just something to consider for the future.

The controller doesn't let me enter a higher value than 150 probably because it's locked so I guess there's nothing that I can do about it except upgrade. 72200 will probably limit the phase current to 200 so it's not going to do me any good. There is a thread on here of people trying to unlock their Sabvotons with software but from a quick read, it seems only small percentage of people had success so I'm not holding my breath but worth a try.

I do use flux weaking at 50A which is the max that I can set it to and it only increased my top speed by 2MPH so I probably need 100A-120A of flux weaking to get me where I would like to be at. 72200's max flux weaking current is 100A.

I went with QS 273 as it handles temperature better than 205 and it was the only motor that I could find already laced in the size and width of the rim I wanted at the time. I know it's overkill for 8kW.

Also, reading about your voltage sag it seems that something might be off. It seems like you’re getting too much sag for those cells. Did you build the battery? This could also has something to do with acceleration/wheelies

No I bought it from here: https://www.enduroebike.com/index.php?route=product/product&path=137_123&product_id=377

I suspect the sag is higher because it's currently 6C (42F) for me which increases the sag. I finished building this bike October last year so I haven't had the opportunity to ride in warm weather yet to see what the voltage sag is like then.

 

[Eastwood]

The controller doesn't let me enter a higher value than 150 probably because it's locked so I guess there's nothing that I can do about it except upgrade. 72200 will probably limit the phase current to 200 so it's not going to do me any good. There is a thread on here of people trying to unlock their Sabvotons with software but from a quick read, it seems only small percentage of people had success so I'm not holding my breath but worth a try.

I do use flux weaking at 50A which is the max that I can set it to and it only increased my top speed by 2MPH so I probably need 100A-120A of flux weaking to get me where I would like to be at. 72200's max flux weaking current is 100A.

I have the 72200 unlocked version. The manufacturer recommended max DC amps is 250 and the recommended max phase amps for the unlocked is 550, but obviously you can run higher, but run the risk of blowing the controller. I’m not sure the exact limits for the standard 200 amp version but it’s not that much lower. I think the max phase is 400 for the standard version but I could be wrong. Just note that the 200 amp unlocked version is a much different controller compared to 72150. More of a moto controller. It has throttle regen reverse featuring some other stuff and also doesn’t run a display so keep that in mind.
Sabvoton SVMC72200 Powerful Unlock Version https://a.aliexpress.com/_mKmlJiq

Also, for the flux, the manufacturer told me to not go over 60 A for the flux weakening so I’ve never tried more, but you can enter whatever value you want with the unlock version at your own risk

 

[Cr1sp]

The controller doesn't let me enter a higher value than 150 probably because it's locked so I guess there's nothing that I can do about it except upgrade. 72200 will probably limit the phase current to 200 so it's not going to do me any good. There is a thread on here of people trying to unlock their Sabvotons with software but from a quick read, it seems only small percentage of people had success so I'm not holding my breath but worth a try.

I do use flux weaking at 50A which is the max that I can set it to and it only increased my top speed by 2MPH so I probably need 100A-120A of flux weaking to get me where I would like to be at. 72200's max flux weaking current is 100A.

I have the 72200 unlocked version. The manufacturer recommended max DC amps is 250 and the recommended max phase amps for the unlocked is 550, but obviously you can run higher, but run the risk of blowing the controller. I’m not sure the exact limits for the standard 200 amp version but it’s not that much lower. I think the max phase is 400 for the standard version but I could be wrong. Just note that the 200 amp unlocked version is a much different controller compared to 72150. More of a moto controller. It has throttle regen reverse featuring some other stuff and also doesn’t run a display so keep that in mind.
Sabvoton SVMC72200 Powerful Unlock Version https://a.aliexpress.com/_mKmlJiq

Also, for the flux, the manufacturer told me to not go over 60 A for the flux weakening so I’ve never tried more, but you can enter whatever value you want with the unlock version at your own risk

Thanks for the info. I think I'll try upgrading to 72200-M at some point, they are the locked version with display functionality. My battery is rated for 200A burst for 5 seconds anyway so I wouldn't even be able to fully take advantage of the unlocked one without upgrading my battery which I'm not planning to do for a year or two. The front wheel lifts about an inch at the moment so maybe extra 50A will be enough to do the trick.

It's interesting that they told not to do more than 60A flux weaking cause the locked 72220 can do up to 100A, if more than 60A can damage the controller, surely they would've limited it to 50A on the locked one like it's on 72150, I guess I'll have to do some research on that, I know you can damage the Sabvoton if you spin your motor in the air with flux weaking without any load maybe that's what they meant but it got lost in translation? I'll be careful until I can find more info on it.

 

[Eastwood]

Thanks for the info. I think I'll try upgrading to 72200-M at some point, they are the locked version with display functionality. My battery is rated for 200A burst for 5 seconds anyway so I wouldn't even be able to fully take advantage of the unlocked one without upgrading my battery which I'm not planning to do for a year or two. The front wheel lifts about an inch at the moment so maybe extra 50A will be enough to do the trick.

It's interesting that they told not to do more than 60A flux weaking cause the locked 72220 can do up to 100A, if more than 60A can damage the controller, surely they would've limited it to 50A on the locked one like it's on 72150, I guess I'll have to do some research on that, I know you can damage the Sabvoton if you spin your motor in the air with flux weaking without any load maybe that's what they meant but it got lost in translation? I'll be careful until I can find more info on it.

Yeah, I was thinking the same with the flux but haven’t really messed around with it. I’ll probably try 100 A soon to see what it does, I would imagine couple more mph. My top speed is actually pretty slow since it’s a 6T winding. Maybe around 40 mph at 72v.

So what’s your max “rated” phase amps with the 72150? But yeah, if you “can” raise it up to 350 rated phase you’ll be able to power wheelie much easier 8)
My bike does the same thing when the rated phase amps are down to 150a, the front wheel barely comes off the ground.

 

[Cr1sp]

An update on this incase anyone else finds this thread in the future with the same issue. I upgraded to the SVMC72200-M from 72150-M, both locked as MQCON does not sell unlocked M controllers. I was disappointed to find out that the 72200 is locked to 150A rated phase current just like the 72150 however the 72200 has extra 100A for Max and Protective phase current, it went from 350A max and 450A protective to 450A max and 550A protective luckly this was enough for the bike to start wheelieing on it's own without me changing my seating position or pre-loading the forks to get the bike to wheelie.

I didn't increase the DC current from 150A to 200A because my battery is rated for 150A cont. and 200A burst for 5 seconds so the extra power is coming from the phase amps and not DC current, I'm not even sure what performance gains I would get if I increased the DC current from 150A to 200A but at the moment I'm happy with the 72200.

 

[amberwolf]

so the extra power is coming from the phase amps and not DC current

Technically it's extra torque, not power, but as long as it does what you want!

 

[Eastwood]

I'm not even sure what performance gains I would get if I increased the DC current from 150A to 200A but at the moment I'm happy with the 72200.

It would give you harder acceleration. I can tell a huge difference in acceleration, just from bumping up the DC amps around 20a increments. I’ve never taken my DC amps past 180 because of battery limitations and that’s already pushing it with tons of voltage sag.
Example: when I run 100 DC amps compared to 150 DC amps it’s like night and day difference. I can only imagine running 200 DC amps with my unlocked Sabvoton.

Then, technically, you can run the unlocked version at 250dc amps and 550phase safely without blowing the controller. Plan to try this eventually once I get around to building a battery for this bike. All my time and resources has been consumed on my Rmz conversion.

 

[dominik h]

Just checked the rated amps on my SVMC72150. No matter if I set 180A or 30A acceleration is the same. Phase amps is equal to tourque during acceleration and dc amps changes the max power in the midband.