BBSHD showing watts dropping under acceleration

[djneils98]

Had a BBS02 installed on my bike for a few weeks now but today got the chance to test out a BBSHD so swapped over.
It all works well except that when under full throttle the watts meter on the display (500c) drops from showing about 1200w to virtually nothing. The motor is still putting out power and the bike goes very fast still.
Also I would have expected the max watts to show about 1500w nor 1200w - it's a 52v battery and the BBSHD firmware is limited to 28 amps (that's how the 52v ones come)
Could the problem be the battery not being able to provide enough amps? it is this one I got from Eclipse and it says it is capable of 29amps continuous and 39 burst.

 

[Fordulike]

Depends on how it's programmed. There's certain settings in the firmware that can certainly affect performance.

Without scrutinizing the controller parameters, it would be difficult to say exactly why it's performing like that.

 

[djneils98]

Depends on how it's programmed. There's certain settings in the firmware that can certainly affect performance.

Without scrutinizing the controller parameters, it would be difficult to say exactly why it's performing like that.

 

[guerney]

Shouldn't the "End voltage" on the throttle handle be higher than 10? I have a BBS01b 36v and my "End voltage" is 35.

 

[Fordulike]

'Keep Current' at 10% on the PAS page, will be killing the power once the bike is going.

Not great for hill climbing, but if the terrain is totally flat, then good for battery economy.

 

[guerney]

I keep my "Keep current" at 80%, because I don't like hard work. It was originally at 20%. Riding my bike feels like flying.

 

[djneils98]

I keep my "Keep current" at 80%, because I don't like hard work. It was originally at 20%. Riding my bike feels like flying.

do you think that could be what is making the watts drop at full throttle then?

 

[guerney]

do you think that could be what is making the watts drop at full throttle then?

Unless one of the real experts on this forum says so, I'd push "End voltage" higher than 10. Mine is at 35, and my battery is 36V.

 

[djneils98]

View attachment 44267


Unless one of the real experts on this forum says so, I'd push "End volatage" higher than 10.

thanks - I will try this and set the keep current to higher too and see if it makes a difference to the issue - it's torrential rain currently so will probably be tomorrow now to test. Thanks

this guide also suggests the values you guys have identified should be changed https://electricbike-blog.com/2015/06/26/a-hackers-guide-to-programming-the-bbs02/

 

[guerney]

do you think that could be what is making the watts drop at full throttle then?

Here's a load of useful info about what the settings do:

Bafang Programming - Learn how to improve your Bafang mid-drive ebike - Edrivenet

Learn how to improve your Bafang mid-drive ebike. Reprogramming your Bafang mid-drive system can improve the usability and performance of your ebike a lot.

edrivenet.com

 

[guerney]

I wouldn't set "Keep current" at anything near 80%, if I were young and fit, but I'm old. The lowest I can cope with is 60%, but too high stresses everything - try 20% and work up if you have to, is probably the safest way to go with "Keep current" on such a powerful kit as a HD (probably).

 

[Fordulike]

do you think that could be what is making the watts drop at full throttle then?

Are you actually using a throttle, coz I would have thought with the start and end values being the same, the throttle wouldn't work?

 

[wheeliepete]

I read this blog, and many others, when I first got my HD in 2016. Helped me understand the effect of changing settings, and the dangers. Applies to 02 and HD.

A Hacker’s Guide To Programming The BBS02 & BBSHD

One way that the BBS02 middrive unit shines over other competition like the Bosch is the ability to program the controller yourself. Although the process of programming the controller will void any…

electricbike-blog.com

 

[djneils98]

Are you actually using a throttle, coz I would have thought with the start and end values being the same, the throttle wouldn't work?

yeah the throttle works for sure. it's set to the PA level (on my bbs02 it was set to 9 all the time)
on PAS level 9 when I use the throttle the bike goes fast but the watts level on the display suddenly goes from showing about 1200w to like 50w or something.

 

[guerney]

I read this blog, and many others, when I first got my HD in 2016. Helped me understand the effect of changing settings, and the dangers. Applies to 02 and HD.

A Hacker’s Guide To Programming The BBS02 & BBSHD

One way that the BBS02 middrive unit shines over other competition like the Bosch is the ability to program the controller yourself. Although the process of programming the controller will void any…

electricbike-blog.com

@djneils98 It does say:

End Voltage(x100mV): 35\35\42\35\35 – You can set the max range to 42 which is the max input the controller accepts from throttle input 4.2v. If you set lower than this value your throttle response is not as linear or smooth as it could be. Matt suggests you set start voltage to 11 and end voltage to 4.2 for a wider range of throttle response and smoother control of motor output.

 

[djneils98]

I have tested again and the problem remains - I noticed that the freshly charged 52v battery drops from 58v to 50.4v under full throttle - could this be the issue?

 

[guerney]

I have tested again and the problem remains - I noticed that the freshly charged 52v battery drops from 58v to 50.4v under full throttle - could this be the issue?

If your throttle is working, the voltage drop is just voltage sag. It's happening because you are using throttle (also occurs with PAS)- the same happens on my bike, if using throttle or PAS.

 

[djneils98]

If your throttle is working, the voltage drop is just voltage sag. It's happening because you are using throttle (also occurs with PAS)- the same happens on my bike, if using throttle.

thanks. - just tried another display (C965) and something strange happens - it powers on then after a few seconds shows error 30h. the 500c doesn't show that error and both worked fine on the bbs02. Tried a new cable from the bbshd to the display and same issue. very confused now as to what is wrong - could the BBSHD controller be faulty?

 

[guerney]

Have you damaged the wiring harness?

Desperate: Error 30H - Replaced all but the motor!

Hi Everyone, I'm at wit's end, having read every piece of information regarding Error 30H on the net and being unsure whether to sell my parts or to sink more money into getting my BBS02 back up to speed. A few months ago, my display began giving me the ‘Error 30H’ message and then ceased...

www.endless-sphere.com

 

[djneils98]

Have you damaged the wiring harness?

Desperate: Error 30H - Replaced all but the motor!

Hi Everyone, I'm at wit's end, having read every piece of information regarding Error 30H on the net and being unsure whether to sell my parts or to sink more money into getting my BBS02 back up to speed. A few months ago, my display began giving me the ‘Error 30H’ message and then ceased...

www.endless-sphere.com

not at all - motor is brand new and very carefully installed