I have a Halfords Assist ebike that's not working... I can switch on and the lights come on, but as soon as I turn the pedals they switch off. Should I suspect the controller?
The serial number on the controller is b-wzkd2413ka-jm105-f4
I can't find the same one for sale online, but I do find various others that have similar ratings and the same connectors...
I'm new to this - any advice most welcome!
Your first port of call is to test the battery under load with a meter , check what occurs with the battery voltage. A knackered battery in most cases will always show voltage and charge but any undue current draw may cause the voltage to sag/collapse it is this that will define the battery as knackered if proven.
Next try to see if the bike works without switching lights on , it is possible there is wire short or another issue , which may simply be a knackered battery.
You haven't told us very much about the battery bar the age isn't known.
Tell us some figures for the voltage you are seeing !
If a 24v battery do you see 29.05v - 29.4v when fully charged ?
if a 36v battery do you see at 41.5v - 42v when fully charged ?
With an older or unknown bike one has to first rule out a battery issue before making or taking wild guesses at what may be wrong.
Typically if the system swithces on and stays on then one can at the least know that power supply is good and getting thru, the lights draw vey little power less then 1a typically, so not enough current draw to cause failure.
PAS will induce higher current draw via the controller , this will ask the battery to supply said current draw . It is at this point if the battery is knackered that the voltage will collapse under the current draw asked of it so one needs to test with a meter and watch the voltage to see what occurs.
One can test the bike temporary to rule out any system failure by connecting the ebike/eapc battery charger direct to the controller wiring , if the bike works temporay without issue then the battery is at fault.
As said just because a battery has volatage it is by no means an indicator that said battery is any good.
Unusual to occur but sometimes the voltage out put regulator in the controller can fail and this will cause the symptoms described but it is rare. I have only seen it once occur with my bikes in the last ten years and known fully charged batteries in good condition would not work until the controller with the fault was replaced.
One can't jump to any conclusion until the battery state has been ruled out as the cause.