Electric Bike Stopped Working........ Help!!!!

[JuicyBike]

Sorry, should have been more clear. Check the cables to the throttle aren't broken and then reconnect it, disconnecting everything else but the motor and battery.
Perhaps taking a break would be sensible. There's always tomorrow and perhaps someone else might give an inspired input in the meantime...

 

[chris301up]

Right.That's It...! I have now totally given up.... Going to take the whole damn bike to the local tip... !

 

[neptune]

Please do not dump the bike . First of all, prove the battery . To test this in a meaningful way , you need to test it under load. I am assuming your battery is nominally 36 volts. So obtain 3 twelve volt car headlamp bulbs and connect them in SERIES. If you do not know what this means, please ask . Connect this series string across the battery. The bulbs should all light brightly. At the same time connect the voltmeter across the battery, and note if the voltage drops when the bulbs are connected, and by how much. When you have proven the battery, let us know. Together we can crack this without a doubt. If you MUST dump it, dump it in my garage!
You have proven the LED voltage display works by connecting it across the charger. I suspect that you have a high resistance connection either in the main battery leads or in the intercell connections,or a duff cell . I have been misled like that before , you would still get an almost normal reading on a voltmeter, but the resistance would prevent any meaningful current draw. That is why auto-electricians use a rest lamp instead of a volt meter. Car flasher bulbs in series would do , and they are cheaper, but will only pull about 1.75 amps as opposed to headlamp bulbs which will draw about 4 amps.

 

[JuicyBike]

Neptune's right Chris, you shouldn't give up. I just wish this was one of our bikes so I could better help.

 

[Dreamer]

Hi, New member just joined to try help you out bud. Dont do forums to many trolls these days anyways hello all and here goes.

My bike (905se) had same fault - turn the key and the lights flickered and then all went dead. Battery was measuring 40 odd volts too when disconnected and charging fine.

After checking everything out i found it was the BMS (board in the battery) my bike is one from the first batch in the country so fairly old and I didnt want to invest in a new battery.

So... to check if yours is the same try the following

Connect it all up to normal order
Inside the control box at the pedals find the wires from the battery(big white connector?).
Stick a digi multimeter in there (key to off position at this point)
Turn the key and see the voltage if it is way less that 40 volts prob be the BMS like mine(i got 40 then jumped to 200mV as the lights dimmed)

To get round this issue open the battery and cut the black wire close to the BMS board(make sure its the one that goes to the kettle plug not the charge on) and connect it direct to the battery.
This shorts out the BMS board and gives power direct.

This isnt ideal for all be warned that overloading the cells can happen now as the battery management will not cut in to protect them but its an old battery I have got and saving up for new bike so will keep me going in the mean time.

Hope this helps if you have any probs with above chuck a reply up. I will keep an eye open for a response. Good luck.

 

[banbury frank]

Hi the other thing you could try is to try running the motor with the drive wheel off the ground The charger plugged in this will show it is the battery as the charger has enough power to run the motor with no load on it

Frank

 

[Dreamer]

Hi Frank was going to call you next week about the COMMUTER PLUS bike will pm you tomoz if that ok dont want to hijack a thread.

Must be fate

 

[chris301up]

Thanks for all your advice! I am going to have one final go with it today .... But I'm not going to hold my breath.... I am going to strip the battery down and take a look at the board.

I will say I have tried connecting the charger direct to various components and nothing happens, except for the displayer unit which illuminates if connected direct to the charger, but NOT if connected to the charger via the controller unit. (That's the charger connected to the main power feed into the controller unit).... This is why I mentioned in an earlier post that I suspect the battery, or the charger itself....?

I have been trying to find someone local to me who may have a charger of the same type to see if the battery will charge? I have a shop some distance away who supply other electric bikes and I was thinking of calling in, but the last time I went there they were not very helpful at all......

IT DOESN'T REALLY HELP NOT KNOWING THE MANUFACTURER OF THE BIKE.... IF I COULD ONLY FIND A WAY OF SORTING THIS OUT......?

 

[banbury frank]

Hi Chris

I would like to help you sound very frustrated where are you in the Uk



Frank

 

[chris301up]

Hi Frank. Frustrated is not all I am..? Anyway, I live in Rowley Regis which is about 4 miles from Birmingham city centre.

 

[banbury frank]

Hi Chris you not far from Banbury You are welcome to my workshop for some diagnostics Free

I am hear over the holidays

Please free to call 01295275998

Frank

 

[chris301up]

Thanks for the offer Frank. Will bear it in mind.

Just to let you all know I have just connected 3 (tried, tested and working) 12 volt bulbs in series, connected them across the battery power output, and they don't illuminate.

Tried the same across the battery charger, and except for a few expected sparks when connecting, again nothing....!

I have now removed the displayer unit (which is marked as 36 volts) from the bike and connected that across the charger, and all LED's illuminate, so in my opinion shows that it is a least discharging some voltage, possibly the full 36 volts?

I have connected the displayer unit across the battery output, and still nothing, so this is starting to look like where the fault possibly lies?

Don't know why the 3 bulbs wired in series won't illuminate though..?

 

[paulhipwood]

Have just sent a PM
Paul from Halesowen

 

[Dreamer]

When you say you connected across the battery, do you mean inside across the actual cells?

Did you read my post chris? post 45? tis exact same fault as I had with a fix.

 

[neptune]

The most likely reason why your charger will not illuminate the bulbs, is because it is not capable of supplying the necessary 4 amps. there should be a label on the charger stating the amps output, probably 2 amps. The sparks show that current is flowing through the bulbs, but not enough to light them. The fault is definitely in the battery cables, the cells, intercell wiring or BMS.

 

[chris301up]

I actually connected the displayer unit across the power wires from the battery.

Yes did read Dreamers post - but have left that has a last resort for later today.

I have just borrowed my son-in-law's multimeter again and run some basic tests. The battery charger produces between 39.5 & 41 volts but NO AMPERAGE whatsoever. This would account for the inability to light the bulbs wired in series. I would have thought this would have discharged some amperage, even a small amount?

It appears the battery is now fully discharged so cannot get any reading from this at all. It certainly now appears that the fault is either the battery or charger?

 

[oigoi]

Sounds to me like the bms has disconnected the battery due to the low voltage cut out in the BMS disconnecting it to protect it.
You could pull the battery pack apart and see what voltages you can measure? the cells could be fine but the BMS might have gone wrong and disconnected the battery

THe other possibility is that no current is flowing from the charger might mean that there is a fault with the bms or the battery and not necessarily the charger. Would perhaps be helpful if you could borrow another charger from someone and try it on your battery. Either that or try connecting your 3 12 volt bulbs in series to the charger with the multimeter and see if the charger puts a current through the bulbs

 

[Dreamer]

Tis A fix for mine bud if yours meters out the same as mine then prob be the same fault is all i am saying.

Current can only be checked when there is a load drawing some juice of the supply?

Think of it as water flow through a pipe if the pipe is blocked no water can flow?
Sure i will be corrected if I am wrong above.

Id hook the load ( lights ) direct across the battery positive and negative terminals that takes everything else out the circuit and will check your cells direct(direct onto the battery cells inside not terminals on casing). Then do the same after the battery board. Meter the voltage as you are doing the above and disconnect the battery from the bike. This is to check the battery and battery board only. Trying to narrow down the fault. If that works it is good sign i suppose as it takes the expensive bit out the circuit.

Nice to see your not giving up took me a while to get mine going again. hope this helps.

 

[neptune]

WARNING. You must not try to measure the output of a charger by connecting a multimeter directly across the charger with the meter on Amps. By doing this you are effectively short circuiting the charger as your meter will have zero resistance . If you have already done so you will have damaged the charger, or at least blown a fuse .The correct way is to put the meter in series with a load, for example your string of lamps.

 

[chris301up]

I DIDN'T REALISE THIS. We did measure the voltage and amperage across the output connections,so I bet it's knackered now? We live - and possibly learn - then?