NCM battery problem

It's dirty contacts on the battery button, I always open it up and clean it with electronics contact cleaner.
Hmm? Could be a broken contact ´in´ the battery? You might want to talk to the seller about
a return. How many kliks?
Thanks for the reply, it is a bit strange as it was working but has developed a fault whilst not being used,which is why the dirty switch contacts made sense.
I removed the top of the battery and sprayed switch cleaner over the switch area and checked the fuse,which was ok.
The problem is ebike battery companies just want to rebuild the battery with new cells and do not want to get involved with the control unit.
I purchased the bike direct from Leon cycles with a one year warranty on the battery,which has now expired,, but it is easier to contact the Pope than them.
I removed the top of the battery and sprayed switch cleaner over the switch area
Not good enough. You need to get cleaner inbetween where the button sandwiches right over the contacts.

All you are doing is getting a blanket of snow on the roof without cleaning the house.

This was a very common problem with early flip phones and button devices like blackberries. Oil from our hands and face eventually seeps under the button pads. I haven't had to fix any since the advent of smart phones.
Hi, thanks for the reply, I did spray in all spaces around the switch including above the contacts between switch and case, but I will give it another go.
Interesting metaphore by the way.
Here's a typical button you can find on many electronics, from a radio to an air conditioner.

Ideal would be to open up the button housing. But I can't since that will destroy the button. I get enough cleaner into its housing by the gaps of the button, and then massage the button by pressing down and rotating it.

Getting cleaner anywhere else outside of the housing, such as the circuit board, is useless and you're just making a mess.

And be sure to use a REAL electronics contact cleaner. Most household cleaners such as WD40, are NOT.

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Hi, I am using an electrical contact cleaner, the switch is not an enclosed unit as you have shown, I can get the spray behind the button onto the circuit board it operates on. I fear that it is a component failure on the pcb.
The button on the board is a simple momentary on short.

If you feel confident, short where you think the button does the contacting.

Hard paper clip is preferred over wire, as the wire may dance around and touch other unintended areas.
Sorry to here the franchise you bought from is unresponsive. the store in seattle near me has been
very helpful. They are currently offering a new 13ah for $300, & 16ah for $400. Still, I think you should
be entitled to a replacement free or at least a signifigant discount if the failure is in the circuit board
or cell connections.
So if I understand correctly:
1) Battery was working before, you had ended a ride and fully charged the battery but it then it stopped working
2) Battery does not power the bike
3) Pressing the on/off button on the battery does nothing. Did you try long pressing for 15-20sec?
4) No LED's on the battery at all
5) You've opened the battery and checked both fuses. There's a 15a-20a discharge fuse at the top and a 5a charge fuse at the bottom (usually).
Does the USB port work?

My feeling is it's the discharge fuse but you say you've checked it. I think it's time to get a multimeter (are you comfy with that sort of thing).
Check the power on the discharge port at the top. Anything?
If you can carefully probe the charge port (BE CAREFUL, use a 2.1mm barrel connector from an old wall wart to make a plug to use to test with) what is the voltage there?
Opening the top of the battery can you trace wires back from the discharge connector to the fuse then to the BMS. Check for voltage everyone along that path you can and let us know what you find.
Post some pics of the BMS and wiring at the top of the battery