BBSHD with 10s 36V battery?!

fpdragon

1 µW
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May 28, 2021
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I have ordered a BBSHD with all accessories (programming cable) and I want to run it with a high current 36V battery pack (2 times 5S).

I already tested and it seems to work fine in the first tests. However I noticed that the programming software is quite limited. The lowest Low Battery Protect Value is 37V which is higher than the nominal voltage of my battery.

I noticed that it is possible to programm the whole firmware.

Is there a way or a mod to lower the Low Battery Protect Voltage?
I would like to set it to about 32V or 33V.

I noticed that the "STC-ISP" programming tool has a field that is called:
Low Voltage reset - LVD detect level
and the values are very low at about 2.63V
Can I edit this value to overrule the setting in the szbaf config tool?
 
motor is designed for 48v/52v the LVC cant be tuned lower to my understanding



a bbshd isnt the kind of motor you would run at those kind of power levels anyway.
either get a higher voltage battery or a less powerful mid drive

you may have better luck with the opensource firmware https://github.com/danielnilsson9/bbshd-fw
 
May help you lower low voltage cutoff under 38V with original firmware, so 36V battery becomes usable on this motor.

But you would have to flash altered firmware + donate something that goes over threshold of motivation to send the file.
 
izy said:
a bbshd isnt the kind of motor you would run at those kind of power levels anyway.
either get a higher voltage battery or a less powerful mid drive

Nonsense. Pairing a 48V BBSHD with a 36V battery would make it a much better match for most people's natural pedaling cadence. Running it at the higher speed only really makes sense for people who don't pedal along, or those who are comfortable pedaling at very high RPM. When running at a slower RPM, it becomes even more important to have adequate torque, and BBSHD is better designed for that than low power units.
 
Chalo said:
izy said:
a bbshd isnt the kind of motor you would run at those kind of power levels anyway.
either get a higher voltage battery or a less powerful mid drive

Nonsense. Pairing a 48V BBSHD with a 36V battery would make it a much better match for most people's natural pedaling cadence. Running it at the higher speed only really makes sense for people who don't pedal along, or those who are comfortable pedaling at very high RPM. When running at a slower RPM, it becomes even more important to have adequate torque, and BBSHD is better designed for that than low power units.

i mean instead of doing high torque at low rpm
surely you go with adequate gearing as that makes no sense and is literally strain on components

also the BBS02 has more torque at lower rpms as proven here https://endless-sphere.com/forums/viewtopic.php?f=2&t=100461

even if you sim it on gradients for torque the bbs02 produces more torque at less amps and wh required only difference is about 7-9c

its only at higher rpms where it pulls out but thats also with both motors requiring 48v to get to those rpms.
at 36v the bbs02 pulls ahead

but like i said you can probably program it with the firmware i linked
 
Good to know that the BBS02 provides more torque per amp. Still it doesn't seem as well constructed to handle such torque as BBSHD. But that's another point in its favor, along with narrower pedal spacing, lower weight, and lower cost.

Every electric motor makes maximum torque at zero RPM, with torque decreasing as RPMs increase. The problem arises when you let the thing bog down into an inefficient RPM range and run hot. From what I can tell, many BBS02 and BBSHD users do exactly that.
 
BBS02B for those effectively using the gearing and shifting as if there wasn't a motor. I've seen quite a few overheated BBS02's from taking off from a stop by throttle instead of the proper gear.

The BBSHD can take more of a beating. I rode mine for 4 years in a flat city never shifting. 3rd or 4th on a 7 speed with a throttle start. I sold mine as I just didn't need to ride 33MPH.

Several shops we work with are convinced the BBS02 500W versions are the most resilient.
 
Chapeau said:
So, @fpdragon, have you tried to use your BBSHD with a 36V pack ?
Why? the LV cutout won't allow a max 42V battery to work.
 
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