Bafang de-tuning
 

Hi, Can anyone please help clear up these ?s for me, in regards to de-tuning a Bafang 02 750W that sits on a 52v battery.
Tuning down to 500W: Is it safe to do so with this battery? Also what are the advantages or otherwise in so far as power, overall battery\mileage range etc., if all were things were equal in pedalling input, gradients etc.?

Thanks!

Reducing the current setting will reduce power consumed which will increase range and your motor will run cooler. I have a 36v BBS01 with current set to 18a so my peak power is 648w. Setting your bbs02 current to 14a would produce a peak current of 728w. Combined with the wider stator of your motor, when compared with my system yours will be able to climb steeper gradients or travel up hills faster or easier with the same level of pedal effort, and as a bonus you will be under the 750w power limit in most states.

But I don’t have a bbs02 and someone with considerably more experience like Karl Gesslein recommends 18a which would be 936w peak, enough to comfortably climb most hills.

de-restricting Bafang 750v
 

Thanks for your very informative reply Dewey. Will search for and check out Karl's info tonight!

Regards, Oscdav.

Why do you want to detune? Knowing your goals may help us.

Remember: Power = Voltage x amps.

you can do a battery swap to 48v with no problem. Because of the LCV (lower cuttoff voltage) you can't go with a 36v battery as the controller will cut out something below 48 volts.

I'm over simplifying, but
Volts = speed
Amps = torque.

Lower voltage means the motor will be running at a lower speed. As you are running through a drive train, this isn't that critical (like it would be with a hub motor).

Lower Amps means less torque (twisting power). So the bike will accelerate slower and climb slower.

As Dewey101 said, Karl has great documentation.

Personally, I use 36v and low current on a hub motor because I want a light bike (small battery) that encourages me to pedal (and doesn't just over power me).

If you really want hard numbers, go to the simulator, pick a random number, and play with the battery, current voltage numbers to see the change in speed, power, acceleration, range, time to overheat, etc.

If you are just changing the current, the bike will pull less hard (accelerate slower)

Detuning
 

Thanks Chas,

Very well explained. I find the 750w a little over powered for my needs. Having your Voltage x Amps explanation confirms that an allowable 52v battery, along with detuning will give me less torque, but more range. Thats what I'm after!

Cheers,

Oscdav.

Since it is a mid drive, and you probably have gears on your bike,you can always downshift to make up for less torque from the motor if you limit the max current. .

I suspect your problem with the 750W BBS02 is the overly strong pedal assist. Have you changed it to increase the available settings. Mine came default with 3 levels, and level 1 would pedal me up to around 16-18 mph. I changed to to the max, which I believe is 9 levels. That dropped assist level 1 down to around 12 mph at 48V. Probably a little higher with 52V. The BBS02 has registers to adjust the assist levels if you wish to do so. I cannot comment on that process, not being much interested in changing anything in my BBS02, but I believe you can weaken the assist quite a bit for a particular level.

One of the better ways, I think, to increase range is to use PAS 0, no assist, and ride it like a bike. Use throttle as needed. My BBS02 came programmed to allow throttle in level 0, and I understand some do not. That's set with the programming cable.