battery failure after 100km ride

[giacomo]

hi,

This morning I was bicycling to work, like very day I do since I got my bafang bbshd on my mtb,
but this morning after just 3 km from start driving from home, while I was on flat road, speed assist 5. speed circa 40 km/t and gear 34 in front and 11 in the back

suddenly the bike stop work! Fist thing that I have do was disconnect the plug that go from the battery to the motor and try to press the button on the battery (the battery is an HL 14Ah 30A continuos discarge) the led indicator staied on just half second and blinked red..

what can be? the battery was full charged just before start the ride, can be the bms fried?

thanks for your help!

 

[LockH]

Hi Norway. (Canada here) Hope others more "techie-minded" will help... but just curious about your "HL 14Ah 30A continous" battery please? Is it a "freshie"? ie any idea how new it is/how many cycles it has been through... And, "full"/deep discharges any/many times? Which lithium chemistry? (Any links to a suppliers website...) Voltage rating?

Cheers
L

 

[giacomo]

Hi Norway. (Canada here) Hope others more "techie-minded" will help... but just curious about your "HL 14Ah 30A continous" battery please? Is it a "freshie"? ie any idea how new it is/how many cycles it has been through... And, "full"/deep discharges any/many times? Which lithium chemistry? (Any links to a suppliers website...) Voltage rating?

Cheers
L

hi that is the kit that i have https://www.aliexpress.com/item/48V-1000W-BBS03-BBSHD-Bafang-8Fun-mid-drive-electric-motor-kit-with-48V-14Ah-Li-ion/32670265014.html?spm=2114.13010608.0.0.JgGDbS

same battery same motor

all new, just got to ride 100 km... today i am goig to open the battery and check..

 

[amberwolf]

Probably one or more of the cells in a group are either not connected or not as good as the other cells, so the whole group has a lot lower capacity than others.

There could even be several groups like this.

When using it for shallower discharges it might not even be a problem, but when using it a lot more, running those groups down close to empty, then recharging it means those groups "fill up" faster than the rest, stopping the BMS from charging the rest of the pack any further. The BMS then has to drain those down, then continue charging the other groups. It can take days or longer, on the charger continously, for this to work.


Sometimes even that wont' work becuase the problematic groups are damaged and simply don't have enough capacity to get you any farther.

Usually all this stuff happens later in a pack's life...but many are not built very well, or of good cells, so even "brand new" packs show these problems.

I recommend looking at the various battery troubleshooting threads in this subforum and ebike technical, and see how to open up and test the cells, and replace the bad ones, or repair the connections if that's the only problem.

Or if your pack has a warranty, I would contact the seller and take advantage of that.

 

[giacomo]

Probably one or more of the cells in a group are either not connected or not as good as the other cells, so the whole group has a lot lower capacity than others.

There could even be several groups like this.

When using it for shallower discharges it might not even be a problem, but when using it a lot more, running those groups down close to empty, then recharging it means those groups "fill up" faster than the rest, stopping the BMS from charging the rest of the pack any further. The BMS then has to drain those down, then continue charging the other groups. It can take days or longer, on the charger continously, for this to work.


Sometimes even that wont' work becuase the problematic groups are damaged and simply don't have enough capacity to get you any farther.

Usually all this stuff happens later in a pack's life...but many are not built very well, or of good cells, so even "brand new" packs show these problems.

I recommend looking at the various battery troubleshooting threads in this subforum and ebike technical, and see how to open up and test the cells, and replace the bad ones, or repair the connections if that's the only problem.

Or if your pack has a warranty, I would contact the seller and take advantage of that.

Hi

Thanks for your replay, Like i sad before I was bicycling to work when the problem arrived, so I had to go back home and take the car. Back home after 8 hour I tried to put on the bike and this time all was normal, it was working again perfectly fine!

So for understand what was actually happened i decided to open the battery.. i discovered that inside it was really wet, full of water, probably because of the rain of the last days.. also the bms was practically all wet... su I let the battery open all the night for let it dry.. but at this point how can i be sure that no demage as accorred to the bms? Shold I do something? Now i am just goig to put silicon for make thia battery weatherproof..