BBSHD program above 30A?

[Alpinist]

I have my controller set on some fairly conservative levels with the help of the Electric Fat bike thread: but now that I have a bunch of miles I want more (shocking I know).

Is there a hack yet for increasing the controller to 35 or possibly 40 A? Is this a bad idea?

I have a Samsung (luna built) triangle battery 25r 20Ah

Anyone have suggestions without doing something that will likely trash my motor? I will probably wait till warranty runs out, so just curious right now.

Thanks!

m

[Eric Luna]

NO there is not any mod for this.

We have got some unpotted controllers we are trying to modify to do just this....but its no easy task. IF you want one to tinker with let us know.

your only option if you are not some electronics genius is to run an external controller....but of course then you have to deal with the hassle of running an external controller.

Eventually bafang will increase the watt limits of the bbshd...but not for atleast a year. At that point we could provide you an upgraded controller so you could get the 35amps or 40 amps we all wish we could have.

The other thing to consider is if you could figure out a way to run more volts to the BBSH you would get the performance you are looking for at the same amp level ;)

[Alpinist]

Thanks for the info Eric. I am going to wait for now, too many project irons in the fire at the moment. Sounds like a promising future though.

[Bruno (YouTube)]

Yes, the programming software, actually the internal controller firmware limits the maximum to 30A. Like Eric mentioned it is very likely that Bafang will increase the wattage (amperage) next year like they did with previous models BBS01 and BBS02.

We all know that the HD is extremely overbuilt this makes the unit very reliable and capable of handling future upgrades (more power).

Just like you, I just got too used to all that power and this is so addictive.. I want more... =]

Eric may have his modified controller available very soon... that would be the easiest option as you can keep the same Bafang display and harness.

I am not waiting for Bafang to increase the power... I will make my move soon... hahaha...

Bruno - www.youtube.com/bruno2bari

[Alpinist]

Thanks for the insights Bruno! More powerrrrrrrrrrrrrr!

(love the videos, been a fan for many months)

[Bruno (YouTube)]

Yeeeahhh.. thanks for that.. there's much more fun coming there hahaha..

The other option Eric mentioned earlier is to get an external controller, some controllers need a display some don't... the Cyclone motor doesn't...

Maybe try to connect the Cyclone controller and pump 40A and see how it goes... there are countless models of controllers (sensored and sensorless) Bafang is sensored (means that the motor has hall sensors to know the motor position).

Playing with electronics is super fun... once you start you never want to stop =]

POWEEEEEER ahahahaha..

[Trailblazer]

Good clean power fun. Love the enthusiasm! And you're right, once you get going, it's tough to not want MORE POWER!

[Crystal Method]

Bruno your my hero!! Your videos are soooo coool. I hope someone can figure out a way to suck some real power through a bbshd or bbs02.

[Eric Luna]

We are going to try to run 50amp through a bbshd through an external controller.

We are going to see if the Bafang BBSHD will take the heat. :)

We will post the results here. Anyone want to guess how many amps we can run at 52v until the BBSHD fries?

[Trailblazer]

57.329A
Thanks for doing the experimenting, Eric!

[Dogboy1200]

Karl proved 65 amps is too much. My guess is 45 amps with no loss in reliability. I'm in for a hot rod controller set up when you get it figured out! Thanks Eric!

[Alan B]

Unfortunately we don't really know much from Karl's experiment. The controller he was using, an 18 FET Xie Chang type as I recall, doesn't measure motor (phase) current, it only measures battery current. He set it to 65 amps of battery current, but at a standstill with no back EMF the controller could multiply that to a much larger value, and the controller is only estimating the motor current using software that may not have the right physical parameters to get an accurate estimate. It is the motor current that is proportional to torque we need to limit and control smoothly to prevent drivetrain damage. So the right approach is to use a controller that measures and controls motor current such as a sinewave controller. Smooth control is important, another virtue of sinewave controllers. Karl's experiment may have put 150 or 200 amps in the motor and clearly the drivetrain and nylon gear are not suited for this.

In terms of the magnitude of current, at high speeds we know the motor current equals the battery current so we know that 30 amps doesn't heat the BBSHD too much. Heating goes up with the square of current so that begs the question, could it handle double the heat? This would correspond to 1.414 times the motor current. Doubling the motor current (to 60A) would produce four times the heat which is unlikely to be safe for continuous application. Of course the time average figures into this also, as well as ambient temperature, cooling airflow, and insulation value of the mud covering the motor.

[JPLabs]

Alan B,

I didn't realize phase current could be so much higher than battery current, relatively uncontrolled, with that type of controller. You make a good case for Sine controllers.

The stock Bafang controller is a Sine controller, isn't it? If so, are there control parameters to adjust how aggressively phase current is applied? Or, do the Bafang configuration variables only act on battery current control?

[Alan B]

I believe the existing controller is a trapezoidal controller, not sine wave. The Bafang controller could do a better job estimating motor current since they know the actual motor parameters involved, compared to the generic ones that are paired with whatever motor. So they can do a fairly accurate estimate. They could even have a motor current sensor in there if they wanted to. I doubt they would go to that cost, it is easier to measure battery current and use the equations to calculate motor current if you know the parameters.

Folks usually set the motor current to 2.5 times the battery current on Xie Chang controllers. But as discussed earlier the actual current may be even higher. But you do have at least some control, it could be set much lower on the programming parameters. Really, as the power levels are raised the motor current to battery current ratio should be reduced. Set it to the same value or perhaps 50% more. Even if the estimate is not right it will reduce the peak value.

I don't recall if there is a setting for rates, I think there is. It is not in very understandable units as I recall. There are long threads on these parameters on ES. In any case the 30 amp limit is not adjustable. I'm pretty happy with it myself, I think putting more than 1500W through the chain and cogs is asking for reliability problems. Higher power is probably best done with other approaches.

[JPLabs]

I see. So the Bafang is fairly capable, then. Good.

It's nice to learn more about controller operation and differences. I know a little about what kind of motor control methods exist, in general, but not about which capabilities are implemented on these Chinese ebike controllers.

Thank you.

[Albeegood]

I made up my mind to stop thinking on finding an external controller to put on mine and just wait for bafang to make one that will replace the original controller or (lol) for Eric to find it in his heart to sell me a Ludacris controller. Besides I don't wanna sacrificing my display and pas. "WE ALL WANT MORE POWER!!!! Right Bruno?

[etriker]

Any word from Luna on the improved more powerful BBSHD controller project?

[max_volt]

https://lunacycle.com/secret/

[etriker]

WHAAHOO! Thanks Max_Volt !! It asks for who & where authorized & a case# ? "Otherwise the order will be cancelled" Pls advise?

[JPLabs]

I believe the procedure is to email support with your order number from purchase of a Ludicrous bike or kit from Luna, and explain why you need a replacement.

I know they are not for sale to the public. They hide that link to prevent confusion and requests.

If you bought your BBSHD from Luna, and asked nicely, you might have a shot, not sure?

[etriker]

Thanks JP, will contact them next week. I'm always nice ;~)