Bafang 250w kit died up a hill. Battery was fine. Any ideas?

Lee

Pedelecer
Jan 3, 2016
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The bike was running beautifully until I slipped and stacked it on the pavement. Restarted the battery and went along ok until we got to a hill and she said "no more". I have very limited tech knowledge but does this sounds like the transformer's at fault? If a kit blows and the battery seems healthy, what's the first thing to give up the ghost?
Many thanks!
 

Nealh

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Aug 7, 2014
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I have decked my bbs01 3 times without issues but it might be possible that if power was on at the time then something like a cap or fet may have been shocked or damaged and then blown in the controller when power was required, if that is the case then new controllers are available. Do some simple checks first like break lever cut offs if fitted, wiring for breaks or damage also all connectors. Other wise it probably means dismantling the motor to look in side.
Light bulb has just gone on check the 30a battery fuse, on the dolphin/ 09 cases it is by the charge socket under a rubber grommet.
Charge the battery and check the voltage output.
 
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Alan Quay

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Dec 4, 2012
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What makes you think the battery is ok? I say this because it could be a duff cell/broken weld.

...but it could also be many other things.

Does it run after you charge the battery?

Check all the connectors, particularly the ones that go from the battery to the controller, and the ones that go to the motor (aka tha phase wires). Its imporant these are all wimell connected.

Hope that helps.
 

Lee

Pedelecer
Jan 3, 2016
46
20
I have decked my bbs01 3 times without issues....
Hi, and thanks!

Mine's an older model I think - the battery is oblongal (i know its not a word) and I can't find any openings for a fuse on it. I'm thinking/hoping it's the controller, as there just isn't any power going anywhere now.
 

Lee

Pedelecer
Jan 3, 2016
46
20
]
What makes you think the battery is ok? I say this because it could be a duff cell/broken weld....
Thanks Alan. The battery appears to be charging ok and the test LEDs show a full charge, just that no juice is getting to the machine. The wires seem pretty well connected but I'll have to have another check. Think I'll take a punt on a new controller as they're pretty cheap, and i've got an old Powabyke Mk2 that might be able to use it as well.
 

Nealh

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Aug 7, 2014
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Hi, and thanks!

Mine's an older model I think - the battery is oblongal (i know its not a word) and I can't find any openings for a fuse on it. I'm thinking/hoping it's the controller, as there just isn't any power going anywhere now.
If no ext fuse then their should be one inside for the protection of other components., you do need to check this first. As you should know when its blown no power will get through so motor will appear dead. Also have a quick read of 'Electric Avenue's thread bike cutting out.
 
Last edited:

Lee

Pedelecer
Jan 3, 2016
46
20
If no ext fuse then their should be one inside for the protection of other components., you do need to check this first. As you should know when its blown no power will get through so motor will appear dead. Also have a quick read of 'Electric Avenue's thread bike cutting out.
Oh ok. I'll unscrew the case and see what's inside! Thanks again matey.
 
C

Cyclezee

Guest
Hi Lee,

I don't see mention of what type of Bafang kit you have, is it BBS crank drive or hub motor?

Have you checked the wiring for damage after you mishap, if it is hub motor check the wires where they exit the motor.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Hi Lee,

I don't see mention of what type of Bafang kit you have, is it BBS crank drive or hub motor?

Have you checked the wiring for damage after you mishap, if it is hub motor check the wires where they exit the motor.
To be honest I didn't give it a 2nd thought and a hub didn't enter my mind, I assumed a bbs but yes a hub is more plausible.
 

Lee

Pedelecer
Jan 3, 2016
46
20
Hi Lee,

I don't see mention of what type of Bafang kit you have, is it BBS crank drive or hub motor?

Have you checked the wiring for damage after you mishap, if it is hub motor check the wires where they exit the motor.
Is hub the font wheel kit? That's what I've got. Sorry - still learning!

The main prob seems to be power getting past the controller as nothing lights up at all. Just ordered some bits off ebay to open the battery and a multimeter so will take a look on friday.
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
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If it's a front wheel kit, then it's a hub motor.

It would help us to help you if you post some pictures.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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When you get your multi meter first check is to switch on the battery and see if 41 - 42v registers on the output terminals, if not then it will be a fuse or wire issue. If you open the casing take pics as you go in case, it helps esp if a wire comes loose.
 
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jonathan75

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Apr 24, 2013
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When you get your multi meter first check is to switch on the battery and see if 41 - 42v registers on the output terminals, if not then it will be a fuse or wire issue. If you open the casing take pics as you go in case, it helps esp if a wire comes loose.
I'd go with what Nealh is saying. The first things to check are the most easily caused /simplest /most obvious as a)they're the most likely and b) they're the easiest to confirm &fix. My bet is the wiring. I'll go further & guess a pin has slipped out of one of the connectors.
 

Lee

Pedelecer
Jan 3, 2016
46
20
When you get your multi meter first check is to switch on the battery and see if 41 - 42v registers on the output terminals, if not then it will be a fuse or wire issue. If you open the casing take pics as you go in case, it helps esp if a wire comes loose.
Sounds like a plan. I've got suspicion it's got something to do with the connectors between the battery and the rack, as there is a significant patch of green corrosion on one of the inlets I've tried cleaning. Will find out this weekend hopefully.
 

Lee

Pedelecer
Jan 3, 2016
46
20
When you get your multi meter first check is to switch on the battery and see if 41 - 42v registers on the output terminals, if not then it will be a fuse or wire issue. If you open the casing take pics as you go in case, it helps esp if a wire comes loose.
I got my multimeter and it's giving me 30 - 38 as a reading. I did a quick how-to-use a multimeter read but think I did it right. Sounds like the battery is ok I think?
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
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I got my multimeter and it's giving me 30 - 38 as a reading. I did a quick how-to-use a multimeter read but think I did it right. Sounds like the battery is ok I think?
You need to test it again, with a fully charged battery. If it's good it will read around 41.5 volts. Anything else indicates problem.
 

Lee

Pedelecer
Jan 3, 2016
46
20
You need to test it again, with a fully charged battery. If it's good it will read around 41.5 volts. Anything else indicates problem.
Ah ok. I just assumed 36V battery = 36V reading. I'll have another crack. It's a well worn battery doing 15 miles a day for 4 - 5 years constantly, but still got me 12 miles a day on one charge until it stopped running suddenly. Would its age affect its output do you know? Would the voltage I'm getting out not be enough to do anything to the rest of the bike?
thanks again!