Yescom Kit 36V Controller internals revealed

[BrandonB]

Here are pictures of it, for those who are interested. 12 FET controller, caps were 63V. FETs marked as STI 80NF70. Many wires removed, including some unused, three throttle inputs (?), output voltage indicator, extra brake cut that was on the throttle. Last picture is of my own doing, I pinned out the serial port just in case I could program it in the future. Controller is marked 36V 500W but by the looks of it, it could be capable of a lot more. Any thoughts?

 

[dnmun]

STMicroelectronics, STP80NF70: BVds is 68V and the max continuous current at 100c is 70A. .0082ohms Rds.

 

[BrandonB]

Going by that figure and the fact that it has twelve FETs, how much current would you estimate it could safely handle continuously? Surely more than 15 amps?

 

[wesnewell]

All 3 of the yescomusa kits I bought came with a 30A controller. I modded one for ~45A almost 2 years ago and it's still working fine afaik. Max fet amperage was already answered above, 70A. But I wouldn't try and go more than 45A without doing some trace mods and adding more copper to them.

 

[geeeyejo1]

All 3 of the yescomusa kits I bought came with a 30A controller. I modded one for ~45A almost 2 years ago and it's still working fine afaik. Max fet amperage was already answered above, 70A. But I wouldn't try and go more than 45A without doing some trace mods and adding more copper to them.

I assume then that this is the same controller provided with my 48v 1000w Yescom kit - question: Am I correct in assuming then if I powered my kit with let's say 12s 2p LIPO at 20C that it would provide up to 1500 watts to the Hub (ie fully charged LIPO at the higher discharge rate providing the maximum wattage @ 30A)?

 

[BrandonB]

The controller probably has a preset amp limit, from the looks of it mine will definitely do more than the 500 watts it is marked, but if it's programmed to do 500 watts, that's what it will do, or at least that's what I am under the impression of. Get a Lyen controller if you want a good programmable controller that can be used for much more power. I plan on getting a serial connector to try to interface the bike today, but who knows if the keywin software will work with it or brick it. I will let you know.

 

[dnmun]

jeremy has a thread on how to spoof the current sensing shunt in the controller. you can add a resistor in a strategic place and it gives you more current without losing short circuit kinda stuff. from what i could understand of it. looked really neat if you cannot program it.

 

[wesnewell]

My yescom 500w kits came with 12 fet 30A 500w controllers, so at 50V they would provide up to 1500W. After i changed it to 45A, I got close to 2500W from a dead stop to wot. The watt rating of controllers, like motors are supposed to be rated, is the continuous operation rating. 500W 24 hours a day and nothing to do with their max output. That is determined by battery voltage times the max amp output of the controller, VA=W. The 1000W kits come with 15 fet controllers. Not sure about other models.

 

[wineboyrider]

Which three wires are for the throttle?

 

[puregsr]

my yescomusa 48V 1000w kit comes with a 26A controller, not 30A for some reason. I'm loving my kit, more top speed would be nice.

 

[DAND214]

More amps wont do much if anything.
Voltage will give more speed and acceleration too.

Dan

 

[EVTodd]

I'm thinking about picking up one of these Yescom kits since they are so cheap. Does anyone know if there is any difference between their hubs that have the silver rings around them (on the side, I assume it's just decorative) and the solid black ones? The ones with the rings are less expensive for some reason, are they older models?

Also, are the 36v and 48v versions the same hub just with different controllers?

 

[wesnewell]

The ones with the rings are the older models like I have. I bought 3 of these kits, two 48V 500W and one 48V 1000W. The motors were not the same. The 1000W mot was a lot more powerful and faster run on the same controller and battery pack. I have no idea about their newer 36V models, but I wouldn't expect the same motor compared to a 48V 1000W motor. So if it's not rated for 1000W it's probably not.

 

[EVTodd]

Any thoughts?

Such controllers was used by the Greeks when attacked Troy, now we have them at the museums.
Generally speaking most cheap hubs and their controllers are now museum exhibits.

Only in the planet Mid-drive there is latest developed electronics technology.

Wow, that's helpful. Oh well, at least you're answering an over 2 year old question.

I kinda doubt cheap hubs are dead. From some of the mid drive threads I've seen I would say a lot of people will probably switch back to them after having problems with their mid drive. There seems to be some reliability issues with Bafang mid drives and most of the other systems like Bosch drives are only available on very expensive bikes. I personally think some of the mid drives are making a great arguement for hub motors. And yes, I've tried both.

 

[wesnewell]

In conclusion Hub motors for bicycles is a dead end, in other applications of EV vehicles other than bicycles, Hub motors will continue to be a good choice.

Nothing could be farther from the truth IMO. A DD hub motor doesn't need constant engineering because it's based on the same principle that has been used for a couple hundred years now. And with the brushless intro around 1962, there's really nothing more to worry about. OTOH, a mid drive has many obstacles to overcome in terms of reliability. Not only do you have to worry about mounting the motor, you have to worry about the entire drive train too. One failure within it and you're dead. The only places I see where a mid drive *might* be advantageous is in really steep hilly terrains and most times a DD hub motor with slower windings will work there. But as far as reliability goes, nothing is more reliable than a DD hub motor. It still works if you completely remove the bikes drive train.

 

[neptronix]

Those are probably some total junk FETs.. coupled with an 80% efficient motor.. blah. You can do much better for a hundred dollars more.