Sabvoton Controller Modification

Found this webpage today, with a mod at the bottom of the page to hot rod the controller. 72150

Translated page:
https://translate.google.com/transl....pl/sabvoton-programowanie-pc-i-konfiguracja/

Original page:
https://ebike.nexun.pl/sabvoton-programowanie-pc-i-konfiguracja/

QS says SVMC72150 is 150A, 350A phase, suitable for QS 273v3 @4000+W

So is the "before" version they're working with here a software-crippled one?

All that mod



does is bypass the current sensors for part of the wiring, so the controller has no idea how much current is actualy flowing.

That means it can't protect itself from exploding when current exceeds what it can handle.

I really wonder what benefit this does in actual numbers

So two of the phases has wires going outside the Amp-sensor. If the phase wire is the same thickness and length as the original "not phase wire being bypassed" then would it be true the power would be +50%.

Does this mean peaks are 50% or more off in the measurments or higher?
Does this mean chances of breakdown increases more than the positive power increase from the modification?

A question I have is what the maximum settings may be in a modification like this as a breakdown mid running with this controller wouldn't be such a safe situation anyone would like to "experience".

Some newer controllers can have their settings changed via bluetooth connection and the qs app. This app has a little higher safety-value so if you'd like the highest possible settings in the ordinary way without modifing - its better via usb and program it though the computer program. - I have only made changes via the bluetooth.

I think:
The ways of usage is. To increase power with mod 10% to 110A battery and 220A phase.
old settings:
100A battery 200A phase
new settings with mod to offset ratio new values are:
71A battery and 142A phase

(new bat wanted A / ratio = bat A, 220/1,55=142, (new phase wanted A / ratio = phase A, 110/1,55=71))

Basically this mod is like the "soldering the shunt" modifications of common shunt-current-sensing controllers; it makes the controller unable to measure what's really happening, so it can't protect itself (or other system components) from overcurrent.

Everything could work perfectly, but only if the controller is well-designed and all the components involved are capable of much more than the controller specification limits.

Since it's very common for these controller manufacturers to use the cheapest parts they can get away with, as close as they could possibly be to the spec limit of the controller itself, then any mod that goes over those specs risks component failure. How bad the failure is depends on what component it is and how it fails, and the circumstances it fails under.


The benefits you can get depend on the motor you are using, and the rest of the system and the situation; if you're basically potentially doubling the phase current (since half of it is passing outside the controller's ability to monitor), then if that pushes the motor far past saturation, then you may get more heat out of it than extra power, depending on motor design and the conditions it's under at the time.

If the motor's not near saturation, you get more extra power than heat, and could be worth doing, as long as the controller itself actually has parts that can handle it.

Has anyone played with he pots that are mounted on the inductive current sensors? I feel it would serve the same purpose as a shunt mod but "digitally" done. I've got my svmc 72150 controller apart now and really want to twist the dials!
Ive made a post about it here. https://endless-sphere.com/forums/viewtopic.php?f=2&t=113428&p=1677416#p1677416

Vw2bugyou said:

Has anyone played with he pots that are mounted on the inductive current sensors? I feel it would serve the same purpose as a shunt mod but "digitally" done. I've got my svmc 72150 controller apart now and really want to twist the dials!
Ive made a post about it here. https://endless-sphere.com/forums/viewtopic.php?f=2&t=113428&p=1677416#p1677416sabvoton-current-pot.jpg

Click to expand...

Looks promising! Did you try it yet? I do not feel the need yet to modify mine, as 8+ kW is enough for my modified ‘normal’ ebike. Surely with 130 battery amps and 350 phase amps I am already pushing the limit of my shunt modded BMS that was originally rated at 60 amps max… . But always good to know how to squeeze some more amps out of the sabvoton!

Also interesting to hear if the case temp (higher?) and the controller temp (lower?) reported by the MQCON software change as a result of improving/fixing the thermal interface by adding more heat paste. Did you see where the temp sensor is located? Hopefully at/near the mosfets?

If temps significantly improve, that would be a good reason to open up any high powered sabvoton to add some thermal paste…

Iambuilderman said:

Vw2bugyou said:

Has anyone played with he pots that are mounted on the inductive current sensors? I feel it would serve the same purpose as a shunt mod but "digitally" done. I've got my svmc 72150 controller apart now and really want to twist the dials!
Ive made a post about it here. https://endless-sphere.com/forums/viewtopic.php?f=2&t=113428&p=1677416#p1677416sabvoton-current-pot.jpg

Click to expand...

Looks promising! Did you try it yet? I do not feel the need yet to modify mine, as 8+ kW is enough for my modified ‘normal’ ebike. Surely with 130 battery amps and 350 phase amps I am already pushing the limit of my shunt modded BMS that was originally rated at 60 amps max… . But always good to know how to squeeze some more amps out of the sabvoton!.

Click to expand...

I didn't end up trying it. I did a version of a actual shunt mod instead. Simply put I added 2x 10ga wires to jump around each of the current sensors and left everything else alone. It worked amazing! Bike has a noticeably amount of more power. It could already wheelie pretty easily but now it's at a point that you really have to be careful!