Power cutting out

Nellie

Pedelecer
Jun 15, 2020
46
13
Good morning all
i have converted my tandem using the parts from an EBCO UCL30. The display lights up and I can cycle through the options . There are three levels of assist plus a button for walking assist. It’s a simple PAS system and walk assist works when you press button turns 3 or 4 revolutions and then cuts out. Same on all three pas settings it engages turns 3 or 4 times then cuts out. I have just had battery recelled by German firm up to 21 ah capacity so I don’t think it’s a battery problem . I don’t think it’s pedal assist sensor because it does the same on walk assist . It has a brake cutoff sensor and I could disconnect it to trouble shoot but being new to this I thought best to ask first before diving in. After pressing all the buttons randomly and pulling brake a few time it will operate again and then just cut out once more. any help would be greatly appreciated thx neil
 

cyclebuddy

Esteemed Pedelecer
Nov 2, 2016
1,557
737
Beds & Norfolk
...I have just had battery recelled by German firm up to 21 ah capacity so I don’t think it’s a battery problem .
It might be if you're using the same TranzX battery BMS/controller from your rack-mounted UCL30 battery. There is a common power-related problem discussed on German forums where after a TranzX battery re-cell the bike misbehaves... although this usually refers to 03/07 batteries (don't know which model yours might be - it might be totally different). Basically it involves shorting some BMS/controller comms memory chip to reset it.

Your issue may have nothing to do with this, but see from post 10 onwards here:

 

Nellie

Pedelecer
Jun 15, 2020
46
13
Hi cyclebuddy well my battery is the BL07 but I’m not getting any of the problems on that thread all the functions work and display the lights come on automatically when I cover the light sensor and when I switch on the backlight for display. The battery power on display has all 5 bars showing. The range indicator changes as I cycle through the 3 power assist levels. I have tried disconnecting the brake sensor and it doesn’t work at all when I do that. When I plug it back in it works again but only for about 3 revolutions. Thankyou for helping though
 

cyclebuddy

Esteemed Pedelecer
Nov 2, 2016
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737
Beds & Norfolk
The comms chip problem manifests itself in different ways - you'd need to scour both German and US forums to see (where TranzX e-bike systems are far more common).

Assuming you've double checked all your connectors/wiring etc (disconnecting the brake sensor usually makes the bike work!) there may be an issue with the CANbus/Logix software - if your UCL30 was >2017. Each component needs pairing, and there's even a field in the software that logs the DESIGN capacity of the battery which will now be well below the ACTUAL increased capacity (which it also reads/stores). Often, reloading the Logix software for your model sorts those issues out (I'm reliably informed).

Good luck sorting it. Others will likely be by with other ideas soon.

EDIT: Are you using the same UCL30 26" wheels on your Tandem, or did you transfer the hub drive to different diameter wheels? You could only change that parameter in the Logix software too.
 
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Nellie

Pedelecer
Jun 15, 2020
46
13
Thx cyclebuddy. The motor and cabling controller etc are 2012/2013 so before can bus era.
 

Nellie

Pedelecer
Jun 15, 2020
46
13
Ok after trying to ride bike a few more times I noticed that the speed counter was very erratic going up to 30 mph very quickly in like 3 wheel revolutions even on walk assist it was going up to 19 mph. Does this mean it is cutting out because it is over 15 mph. Is it the lcd display that controls this or the controller battery interface. I can get a new display for about £65. Have to buy from Holland for controller. Help please
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
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Basildon
You need to find out what's shutting down. Start with the battery. Put a voltmeter on the battery to controller connection and observe what happens to the voltage during the shutdown. If the voltage drops, it's a battery problem. If it doesn't, it's the controller.

Where does it get the speed signal from?
 

Nellie

Pedelecer
Jun 15, 2020
46
13
Battery is a brand new recell will check though. as for speed signal I don’t know the answer to that. I have a brake sensor and pedal assist sensor. The only other wires apart from lights are the motor cable with three phase wires and 6 hall wires inside and the display cable with about 10 wires inside
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
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Basildon
Battery is a brand new recell will check though. as for speed signal I don’t know the answer to that. I have a brake sensor and pedal assist sensor. The only other wires apart from lights are the motor cable with three phase wires and 6 hall wires inside and the display cable with about 10 wires inside
Never make assumptions. you find out what's wrong by testing.

In that case, the white wire in the motor cable is the speed sensor. Most likely cause of tour problem is that you didn't push in the motor connector far enough. It has to go all the way to the marked line.
 

Nellie

Pedelecer
Jun 15, 2020
46
13
I can’t see how I can test the battery to controller connection as once the battery is plugged in I can’t get to it. I have unplugged and reattached motor cable at both ends the motor connector is a massive XLR that screws together. The connectors in controller are JST connectors that plug into pcb checked all the pins and wires all seem to be straight and undamaged.tried to ride and walk but still the same speed reading same as before. I only received the battery back from Germany yesterday it was recelled with Samsung 35E cells I have the test sheet so while I can’t rule it out it seems unlikely. I can just see a red led in the controller flashing steadily about once a second whatever that means.
 

Nellie

Pedelecer
Jun 15, 2020
46
13
“You need to find out what's shutting down. Start with the battery. Put a voltmeter on the battery to controller connection and observe”

ok ive Managed to check the connections and battery voltage doesn’t drop so does this mean it’s the controller thx neil
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,986
Basildon
OK, it's unlikely to be a battery problem. When you looked at the battery connections. How many wires go to it. Are there just the two main ones or are there others?.
 

Nellie

Pedelecer
Jun 15, 2020
46
13
Hi vfr400 thx for taking time to reply. There are 6 prongs points of contact extreme left being negative and right positive
 

Nellie

Pedelecer
Jun 15, 2020
46
13
I’m not sure I understand the battery has 6 different slots in a straight line that mate up to 6 teeth / tines / prongs that are fixed to two piggy backed pcb,s inside the housing that is battery connector/ controller the only wires are the display and motor cable that connect to this. Hope this explains thx neil
 

Benjahmin

Esteemed Pedelecer
Nov 10, 2014
2,485
1,699
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West Wales
I think what vfr is getting at is that of the 6 prongs not all may have cables on. Some use just the outer two as +ve and -ve, as yours does. But some use the other 4 prongs as comms links between battery and controller. He's trying to ascertain if your bike is one of these.
 

Nellie

Pedelecer
Jun 15, 2020
46
13
Hi Benjamin all of the prongs are connected to a small pcb which in turn is connected via an integrated socket and plug to a larger pcb with sockets for cabling to lights motor and display. Ther are traces on small pcb that connect all 6 prongs to circuitry and the connector for the other pcb . In short it looks like all of the prongs have some function but I have no idea what.