BBSHD 52V - Full/partial power cut-outs with stable battery at 54V

Some general troubleshooting thoughts:

If it's something that suddenly started happening (when previously to that sudden point it was always behaving consistently correctly), that typically indicates either a vibration/shock-induced connection problem somewhere, or water intrusion that caused a connection problem. The former is normally at a connector or circuit board. The latter would be wherever water could intrude, and can be inside connector shells or anyplace at all, even up inside wiring. However, the latter *also* is not usually sudden-onset like the former.


If it's something that has been gradually getting worse, a water-induced connection problem is possible, heat-induced connection problem, or thermal paste that was applied too heavily between FETs and heatsinks, or heatsinks and outside world, etc., may now be drying out and leaving an airgap, so that when enough heat is generated on one side of the gap, it builds up isntead of haivng enough conductivity to pass thru and stuff overheats during heavy loading.`


If there is no voltage drop (or rather, no different than when it worked fine) during the problematic times, it is not likely to be a battery issue, or an issue with connectors between battery and controller. If there *is* significantly increased voltage drop, it could cause the controller (if yours has this built into it) to rollback available power when voltage drops too far.

If the problem is actual shutoffs of the system, including the display, etc., then the issue is at the battery itself, where the BMS shuts off it's output to protect against overload. If the problem doesnt' shut off display/etc., then it's not the battery doing the shutoff, but rather the controller.


Regarding changing ssettings to avoid the cutout, that's not a good idea. It's cutting out to protect the system from damage. If you bypass that, then instead of coming back after a simple cutout, it could completley fail (whcih could include anything from just blown fuse to blown controller to blown BMS to actual fire if it is a serious battery issue).


You would want to find the specific cause of the problem before bypassing safety cutouts to ensure it isn't going to destroy things first (and if you find the cause...you can probably just fix it. ).

i have a 13s5p/48v, that i run at 1000 to 1350watts continuously

had a fully charged battery, touched the throttle and lost all power

turned bike back on, had full voltage, touched throttle and lost all power

opened up the battery, had a 40amp fuse inside, it wasnt blown but the plastic fuse holder was melted and warped

I'd double check the Shark's cradle connections as it seems to be a known issue.



As seen in this informative thread...
https://electricbike.com/forum/foru...dcase-battery-documentation?p=35701#post35701

Might be passing enough to power the display and voltage indicator. But not enough to provide full working power.


Regards,
T.C.