Pls help me with burnt Battery Management System for YESA 36V 10Ah

[ozjon]

Hi Guys, great forum!!! Has inspired me already to sucessfully build one ebike $45 Kmart aluminium huffy with 500w GM and YESA 36v 10ah LiPO battery (see picture). Prompt delivery from GM and YESA - easy to install, great power/speed and stamina 50km. So I have been putting together a second bike for my wife but unfortunately with less success (would'nt you know it!). After only a couple of km have burnt the YESA bms as pictured. I stopped quickly when I smelled burning so the battery still holds a charge and no apparent damage to the cells. Can any of you smart guys advise me about what is most likely wrong? Is it most likely to be the second battery, second motor or second controller? I am nervous about trying my first expensive battery on the second bike in case I cook that one too. Maybe it would be safer to try the burnt battery on the first bike as means of isolating the problem. Another alternative is to order a replacment bms from YESA and try again? All advice welcomed. Regards, John, Melbourne, Australia.

[Spacelander 1946]

Where you in regen mode when the BMS unit fried?.....My BMS unit got extremly hot exactly in the same place on the BMS board, I never use regen braking now I now it will blow!....Also Yesa have now improved there BMS unit, have you got the new or old version? Best to contact Sam @ Yesa for a replacement unit....Cheers

[Leslie]

More pics please?

Be nice to see around the solder joints of that burnt transistor or anything under that board.  Some times the solders are just a lot too close and high humidity can cause these things to arc and fuse.  Good idea not using it until you can get it fixed.

You will need to get it repaired.  A TV tech can fix that easy or send it back where it came from.

[biohazardman]

Hi Guys, great forum!!! Has inspired me already to sucessfully build one ebike $45 Kmart aluminium huffy with 500w GM and YESA 36v 10ah LiPO battery (see picture). Prompt delivery from GM and YESA - easy to install, great power/speed and stamina 50km. So I have been putting together a second bike for my wife but unfortunately with less success (would'nt you know it!). After only a couple of km have burnt the YESA bms as pictured. I stopped quickly when I smelled burning so the battery still holds a charge and no apparent damage to the cells. Can any of you smart guys advise me about what is most likely wrong? Is it most likely to be the second battery, second motor or second controller? I am nervous about trying my first expensive battery on the second bike in case I cook that one too. Maybe it would be safer to try the burnt battery on the first bike as means of isolating the problem. Another alternative is to order a replacment bms from YESA and try again? All advice welcomed. Regards, John, Melbourne, Australia.

Your Yesa batts don't want to be charged at very high amps.  The regen probly likes to do that and the BMS is caught in-between not a good thing.  You can replace the obviously damaged components and try it. The battery is not cheap though so you may want to have the assurance of having it right the first time by sending it back or purchasing a new one. Ask Yesa about the regen problem so it does not happen again.