BBS02B started bucking, surging, with power lags!

Denny G.

New Member
About 15 months ago, I installed a Bafang BBS02B on a Bacchetta Corsa recumbent bicycle (see photos). All went very well, great installation, smooth ride, et al, 'till about a week ago when going up a slight grade I noticed a momentary power loss/hesitation. While in power assist with pedals, I could feel bucking, surging, and power lags in my feet. I said, "Oh Oh!" As my ride continued, I could feel these sensations even more. The power output no longer matches what it did with settings at 0 - 6. Eventually, about 15 miles from my return destination, the mid-drive conked out completely, and I was left having to power up hills and over dales using only my legs. I am 82 and the others I was riding with were getting paperwork together in case I died or something. The first thing I thought of was an electrical failure somewhere in the mid-drive assembly. Then whilst reading here and other places, controller failure sounded like a possibility. At any rate, I would surely appreciate any advice I can get from you good folks out there. Thank you so much in advance. PS, I did check power from the battery. No problem there.
 

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Denny G.

New Member
Thomas, you hit on it! Shortly after my original post, I rode my e-bike 'till it totally lost power. I, therefore, tested the battery. No power whatsoever. The problem was p__s poor design of the solder joints inside the battery bracket (Bafang Ultra Slim 48V 11.6 Ah with Panasonic Cells). I had resoldered previously, but road vibrations rendered that fix also a failure. I repaired again; except, this time I have mechanical connections (to avoid melting the plastic plug) to the four inside prongs of the electrical plug, followed with dielectric silicone RTV potting to ensure nothing can move inside the bracket. I have documented the repair here with photos, should anyone else experience my battery bracket failure. Thanks so much for your reply, which is the only reply I've gotten.

By the way, I purchased the Play-Doh from the Dollar Store ($1.00, used to dam the silicon RTV); the electronic grade Silicon RTV for potting was purchased from Amazon (~$10.00). The electrical connectors were from the Home Depot. The padding (excess rubber carpet padding) goes under the the bracket. After a test ride: Quiet and as smooth as silk!
 

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