BBSO2 low top speed

[rammike]

It is always helpful to have a much data as possible to determine what is going on. What is the voltage and current are you seeing at 35km/h? Depending on a number of factors like loading and controller settings that could be the maximum achievable but I doubt it. Unless your load is 200kg and you are going uphill 500 watts (around 10A) should get you close to 35km/h.

 

[Akrotiri]

I have BBS02b middrive motor with 48V battery and my top speed is relatively low I can barely hit 35km/h(21.7mph) while pedalling. My front chainring is 48t and rear is 11-36 and my bike is 29er. What could be the problem? Something wrong with the programming?

Maybe the programming because their controllers are lower quality and far less sophisticated compared to Bosch, Brose and Shimano.

It’s more likely the fact that Bafang tends to over rate their motors wattage by a hefty margin resulting in lower top advertised speeds.

It’s definetly not the battery that’s causing your lower expected top speeds or the drivetrain since you have a 48t front chainring.

 

[Gionnirocket]

Maybe the programming because their controllers are lower quality and far less sophisticated compared to Bosch, Brose and Shimano.

It’s more likely the fact that Bafang tends to over rate their motors wattage by a hefty margin resulting in lower top advertised speeds.

It’s definetly not the battery that’s causing your lower expected top speeds or the drivetrain since you have a 48t front chainring.

Troll is as Troll does.

 

[slitespd]

Gionnirocket, is the 25A a function of the controller regulating it or is it based upon the Amp rating of a battery? I am in the process of gathering things for a 1st e-bike build and don’t want to let the smoke out of any of the components.

 

[Gionnirocket]

25a is the controller Max Amp allowed by default. It is its top limit.
I have mine set to 20a as that was more than enough for my needs.
The battery should be rated to provide that continuously at a minimum.

 

[harryS]

Slitespd. you control the battery amps by whatever you set in the controller. However, you cannot ask for more amps than what the battery is rated to deliver. If you do, you'll get the maximum the battery can dp, like 23A out of a 20A battery, but it ages the battery quickly,

My first BBS02B is set for 25A, and it has been measured to use 25A. However, I never ride faster than 18 mph, so I never worry about smoking it, However, I have hooked it up to overly small batteries. with no amp rating, but I knew they were only good for 12-14 amps. Killed the battery in a week.

 

[Gionnirocket]

Slitespd. you control the battery amps by whatever you set in the controller. However, you cannot ask for more amps than what the battery is rated to deliver. If you do, you'll get the maximum the battery can dp, like 23A out of a 20A battery, but it ages the battery quickly,

My first BBS02B is set for 25A, and it has been measured to use 25A. However, I never ride faster than 18 mph, so I never worry about smoking it, However, I have hooked it up to overly small batteries. with no amp rating, but I knew they were only good for 12-14 amps. Killed the battery in a week.

You can't go by speed as you can easily pull maximum going up hill, especially if you aren't using your gears effectively. I often travel above 20mph pulling less than 8a but climbing can easily reach double that.