I bought a bafang 350w crank drive and a 36v 15ah rack battery. All worked fine then we went away for a week and on return when I turn on the bike the screen flashed on briefly then died. Assumed it was a flat battery so charged it for a few hours but the same problem. The battery charger has a green light so it thinks the battery is fine. I put my multimeter on the battery output and it is showing 53v which is strange. Any ideas on what might be wrong.
Battery problem
- Thread starter jules_wake
- Start date
Ok I disconnected the plugs to the screen and reconnected and it seems to be working again. I would still like to know what happened and particularly whether the 53v is a problem?
It surely must be a 48v battery to get a 53v reading, maybe its labelled incorrectly. Ses if the lcd plays up again and dies if so its because the voltage is too high, I didn't think they liked to be over volted unlike the hubs.
Yes I bought the battery from China it was cheap but had no labels or even documents so no way of telling if it is really what I ordered.. What would be the issue of using an over volted battery
Speed and torque on hubs have seen an increase by up to 30% and seem to handle it well without over heating, but not seen much written about CD's. Being a smaller more compact housing you may well want to keep an eye on any heat issues as you don't want to fry it. Defo sounds like you have a 48v battery what ah it is any ones guess, could be 11.6 ah but that's a guess. Trex rode the 36v GSM at 48v but gave no real feed back except to say it was quick.
You could calculate the ah rating by timing the charge from flat then multiplying by the charger ah rate.
You could calculate the ah rating by timing the charge from flat then multiplying by the charger ah rate.
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I've put in a compliant on alibaba where I bought the battery so I hope they can tell me what they have sent.
For sure i am not going to accept something which is possibly going to break the motor
For sure i am not going to accept something which is possibly going to break the motor
Is it a BBS01 or a BBS02 350W motor? The first is a 36V motor/controller and the second is a 48V motor.controller.
There are stories of over-volting the BBS01 to 48V on endless sphere IIRC
There are stories of over-volting the BBS01 to 48V on endless sphere IIRC
It's a BBS01 36v so it appears I am unwittingly overclocking. I guess the controller is still limiting the speed so I am just getting more watts than normal. I did notice on the screen it sometimes shows more than 350w so perhaps that explains why. I guess the question is should I ask for a replacement. I got hit by an 80 euro customs duty on this one so not keen on being hit for another one! I've put in a dispute on alibaba so will see what comes of it.
http://www.elifebike.com/peng/iview.asp?KeyID=dtpic-2014-8S-T0SC.955NT
Maybe you could get away with just swapping out the controller for a 48V one, first you have to find out the voltage of the controller you have. Try getting a 36V battery from the seller for sure (plus shipping and reimbursement of duties etc.) but swapping the controller if that doesn't work out will be a cheaper option probably.
Maybe you could get away with just swapping out the controller for a 48V one, first you have to find out the voltage of the controller you have. Try getting a 36V battery from the seller for sure (plus shipping and reimbursement of duties etc.) but swapping the controller if that doesn't work out will be a cheaper option probably.
Unfortunately I bought the battery and motor from different sources so I'm don't think the controller option is viable. . Will see if I can get a replacement which is a pain because it took them weeks to ship in the first place.
Just to compound the issue the charger they sent actually has a label which shows it is a 42v how would that work for calculating the AH
Wrong charger, that charger is for a 36V battery. Add that to your complaint about the seller.
I beg to disagree, the OP said the light was green which means the charger had detected 42V so for it the battery was fully charged it doesn't mean that there are 53V in the battery. You can only detect that when checking the battery. It may continue to provide 2Amps to the battery after the green light goes on and the BMS will then stop accepting the charge when it reaches 53V. If I understand how these things work...
I can get that effect by powering the bike on for a bit, then remove the battery and then pressing the power on button. The LCD briefly flashes on probably with the residual power left in the LCD electronics. I think your original problem could be a bad connection possibly between the battery and the controller. It happens to me sometimes when my battery terminals need a clean.
