Help Troubleshooting Dead BBS02

chrisbiggz

1 µW
Joined
Sep 6, 2017
Messages
4
Hi all. First time posting, looking to get myself headed in the right direction. I have a dead BBS02.

Background:
Mid drive BBS02, with a 52v, 13.5 Ah battery pack. 6 months running well. Then I put on the charger, and usually the green light comes on in less than 1 hour but after several hours the red "charging" light was still on. I took it off the charger and couldnt power up the display. Right before this issue came up, the pack that I carry my gear (including the charger) fell off on my ride. I noticed after that there was a tiny rattle inside the charger.

Troubleshooting:
Battery charger output is 58.84v, battery pack is 57.74v. When I plug in the battery, it arcs on the positive side. Then voltage reads 0.0v with it plugged in. Unplugged, it reads voltage again 57 - 58v. Tried to run the motor off the battery charger and the exact same thing described above happens.

I tried bypassing the display by jumping the pins - unsuccessful.

Opened up the controller, found moisture inside due to the gasket not seated fully. Dried it out.

Testing phase wires:
Motor side, ohm across the coils are all 0.3

Controller side, ohm between phase wires and battery supply pos/neg:
Blue = 0.2
Yellow = 4k
Green = 0.2

Controller side ohm between phase wires:
Blue > Green = 0.2
Blue > yellow = 4k
Green > yellow = 4k

Conclusion:
I dont have enough experience / knowledge to say what happened. Seems to be something wrong with the controller side yellow phase. I would really like to know what more experienced minds think happened and whether I should test anything else. Based on what I see I should buy a new battery charger and controller and hope that fixes the issue.

-Chris
 
Hi Chris and welcome to the forum.

First off, chargers tend to be a little delicate and the standard recommendation is not to carry it on the bike unless absolutely necessary, and then give it a lot of protection against being bounced around.

Where are you checking the voltage at, before and after plugging the battery in? It is normal to get a spark when first plugging the battery in, as the capacitor loads up, but normally this causes no problems. If you plug the battery in regularly and get that spark on a daily basis the contact on your plug may have become damaged, and all that is wrong may be the need for a new plug. This spark is discussed in many threads, with different ways to eliminate it. Personally, I just use a DC rated breaker as an on/off switch. The spark still occurs within the breaker but you don't notice it and the breaker contacts are made to withstand it.
 
Rassy,

Thanks for the reply. When Im checking voltage with the battery plugged in im trying to hit the pins where the wires go into the connector. Unplugged im checking voltage on the contact side of the plug.

Good call on getting a dc breaker, I will do that once I get this problem sorted out. I also bought a new plug to try out.

What do you think about the ohm readings im getting on the yellow phase wire on the controller side?
 
Sorry, I don't know what your resistance measurements are indicating, if anything.

I suspected that was the way you were testing voltage, and that indicates that your connection is bad or possibly just very weak. You might try scraping all the contact points on the plugs with a knife or something and testing the system again. Usually the display will power up even if there is an issue with the phase or halls wires so I wouldn't worry about any thing else until you are sure you have a good connection between the battery and the controller.
 
So I put a brand new plug and tried with no success. Nothing. No display etc. So I unplugged it and then plugged it back in. After plugging it back the second time the positive arced and fried my plug pretty good.

on another note how would I get a voltage reading if theres no opening on the battery connector?IMG_20180420_162625558.jpg
 
That is not the kind of damage that is caused by the in rush to fill a capacitor. You must have a dead short someplace. Did your original connector show that kind of damage? Are you positive the polarity is correct on your new connector? That's not a very nice question to ask, but we've all messed up polarity at some point. Maybe there's a short within the sheathing that the positive and negative wires run in which could explain why the sparking showed up on the second time you plugged the connector together. You have a tough problem to solve, maybe someone else will chime in with some ideas.

I have a BBS02 opened up right now (not faulty, working on a modification) so I did some resistance tests. On the motor side I showed 0 between each pair of phase wires. On the controller side I showed 20 between each pair of phase wires. Between the positive lead and each phase wire showed under 20 and between the negative lead and each phase wire showed 10. Not sure how this relates to your tests, but in my case there was no differences depending on which phase wires were being checked and since this is a working controller I would think this indicates there is something wrong with your controller.

Since I know virtually nothing about electronics my normal procedure would be to start substituting parts. The danger of course is that a new part can be damaged if the fault is elsewhere. Your idea of installing a new controller is probably what I would do next.

Good luck on getting it fixed up. :D
 
Thanks again Rassy. Polarity is good and theres no obvious damage on the power wires. I imagine that would cause it to arc like that so I will take a closer look to rule out a short between them, at least before dishing out cash for new components.

The resistance readings are helpful as well. Im not sure what the resistance readings are saying on the controller side but they look bad compared to yours on a good controller. Will update when I get time to work on it further...
 
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