alfantastic
10 kW
I'm seeing vendors selling Bafang BBSHD 52v 1000w 28a replacement controllers. Are these just a misrepresentation of the regular BBSHD 48v 1000w 30a controllers, or actually a new controller from Bafang?
sfbiketours said:Hey all!
So I have a few "old" BBSHDs that run at a full 30A. No surprise but these oldies-but-goodies are a riot and are scary fast hill slayers at full power. However, I just got a shipment of the "new" BBSHD from my local supplier here in San Francisco, California eBike. While stamped 48V 1000W they are fitted with the 28A controller. While annoyed, to me, a theoretical 7% loss at full power is not the end of the world for my use case (bike tours in SF) and I could live with it.
BUT... Curiously, as far as I can tell from testing these don't really work with my 48V batteries (17ah 13s from EM3EV, great batteries) and 500c (aka Mighty Mini) displays. That is, they show erratic behavior when used for a sustained period of time and the display isn't even close to reading accurately (it does OK on the "old" 30A HDs), showing no juice at around a 48v charge. Again, not the end of the world as I typically rely on voltage anyway.
BUT... After relatively short test rides of 3-6 miles exclusively using pedal assist (at MAXed out settings, so full 28A and 100% power in PAS) my power seems to start tapering off dramatically. Meaning at full blast, I can get the bikes up to about 33mph w/ a 42t lekkie and high gear (14t) in the first few mins but I was hobbling back at about 13mph at full power with about 48V left (maybe drawing 300w max) after a pretty hilly 6 mi ride. This is generally consistent with my other tests on different bikes with the 28A / 48V setup. Curiously, I threw the same battery on another bike with 30A controller (all setting same except max amps and exact same componentry) minutes after and without additional charging and bike was back in scary fast beast mode. Oh, and battery was showing about a 60% charge on the 500c display.
Now, I can only deduct a few possibilities: 1) I am wondering if the display reads no juice that if this somehow caps the power output to protect the controller. This seems like a stretch from experience, as none of us trust the juice reading from Bafang displays, but can't rule it out with this phantom 28A setup. 2) That somehow the 28A controller because it's a native 52V setup (As I learned in this thread-thanks!) somehow doesn't like a 48V, the likes of which shows performance loss over sustained output. Also odd. Any ideas?
It seems now that there are only a few options:
1) Ideally, obtain the firmware from the "old" BBSHDs and then flash the "new" HDs to bring them to proper working 30A setup --- any tips would be amazing.
2) Somehow tweak the display. Maybe there is a setting in programming or display settings I'm not aware of?
3) Lobby my dealer to take them back or send me new "old" 30A controllers (not ideal, no win situation as it requires time-intensive rebuilding of a handful of bikes).
Thanks for your thoughts and for reading!
noonedoesnt said:I have this problem too! I am running a 48v 17ah battery on a new june 2020 BBSHD which has the 52v 28a firmware. My exact problem is that when riding, initially, the power is solid 1300W or so, but at only 48v, it already drops to 400-500W output at MAX assist level! I don't know what to do...
amberwolf said:This doesn't really apply to brushless motors the same way it does to light bulbs and simple resistive devices, because the controller is a kind of DC-DC that converts the battery voltage / current to what is necessary to make the motor work, *and* the motor is also inductive, not simply resistive. The power itself will remain approximately constant, minus converter efficiencies.
There is some *speed* loss at a lower voltage, for the same setup otherwise, but it isn't the issue described (and is easily compensated for by changing sprockets on one end or the other).
The voltage differences in these cases are insufficient to see the kind of difference in power output that a simple resistive function would cause.
The probable issue reported with power dropping from 1300w down to less than half that is probably overheating in the drive casing, most likely from riding in the wrong gear, or not shifting down for startups or hills, etc., forcing the motor to have to work too hard at too slow a motor RPM. Then the system lowers the available power to try to let the motor cool off.
The other probable issue, if it's not the above, is the battery itself isn't good enough to sustain the higher power level, and is sagging so much in voltage when it drops down to it's average voltage (vs when it's near full), that the controller may begin operating in a lower power mode to prevent battery damage.
]This doesn't really apply to brushless motors the same way it does to light bulbs and simple resistive devices said:The controller itself is resistive, and contributes to this phenomenon. The other causes you suggested are not possible according to the specific details/component combinations supplied by the original posters.
] the motor is also inductive said:I I'm not sure I understand the significance of this. The magnets on the rotor themselves create resistance to the flow of current, leading to the exact phenomenon I'm speaking of. The fact that the motor is inductive is irrelevant. The magnets on the rotor resist that induction, resisting current flow. This goes to the basic fundamentals of how an electric motor works. As well, although there is a difference between different materials, all materials are resistive.
Can you please provide a link to the different BBSHD firmwares? I'm assuming the new 52v controller is the same controller as before with just new firmware, there's no other difference ??Maugerville said:My firmware was locked to 28A. I flashed the firmware and now run it @30A and have better all round performance. Another bonus it that when using a 48v battery the % gauge on the display seems to be calibrated now.
jtrappett said:A friend of mine bought a new BBSHD with what I assume was the new 52v firmware...it was sold as a 52v motor. When I tried adjusting some of the settings with the programming cable and software it read the existing settings but didn't flash any changes. In fact it then came back with a error code and we couldn't connect to it again, and it wouldn't work.
Not exactly sure if programming had any effects on all of the parameters but I was able to adjust the current settings on PAS levels and make the 0 and 1 PAS level as a zero assist mode with 52V 28A controller and Speeed app. Using throttle only since cadence sensor had some sort of intermittent failure.Can you please provide a link to the different BBSHD firmwares? I'm assuming the new 52v controller is the same controller as before with just new firmware, there's no other difference ??
A friend of mine bought a new BBSHD with what I assume was the new 52v firmware...it was sold as a 52v motor. When I tried adjusting some of the settings with the programming cable and software it read the existing settings but didn't flash any changes. In fact it then came back with a error code and we couldn't connect to it again, and it wouldn't work.
Cheers.