Urban Mover cutting out ?

[Jonathan1]

Hi,

I still have the problem of the power "coming and going" when under load and battery fairly fully charged. I know that there was a view that pedelec sensor was suspect, but the cutting out is not the same as when pedelec sensor cuts power, which is more sudden. Can someone explain for me what protections are in the controller. Presumably overvoltage protection, which I would not suspect, since this happens under load, nor undervoltage suspected since LEDs are within normal range. But how about overcurrent protection, do these controllers have this? and are there any known causes for it to operate.
thanks,
Jonathan.

 

[flecc]

Hi Jonathan, not the pedelec sensor then.

Controller protections are normally low voltage as you've rightly assumed, plus maximum current limiting. I wouldn't have thought a healthy controller would be cutting current on your motor which isn't the most powerful around, but the low voltage may be triggering prematurely if the controller is set high. Has the problem worsened with the cold weather? If so, low voltage sensing is likely, but there are a variety of electronic part failures possible. Contacting the supplier of that new bike asap is advisable if there's any hint of a faulty part.

 

[flecc]

Further info to the above.

The Powacycle NiMh bikes have a battery and motor system very similar to yours, and they suffer intermittent cutting in and out as the battery comes to the end of available charge. This is apparently due to a rather crude form of low voltage sensing.

If your controller is sensing the cutoff voltage too early, aggravated by the cold weather dropping the battery voltage a bit anyway, that system may well give the in and out switching and drive snatching. It's not good for the electronics to carry on like that, best to switch off. I'd definitely say back to the supplier now for investigation of controller and battery, with the former most suspect.

 

[Jonathan1]

Thanks for the replies, Have talked to UM and they still think it's the pedal sensor. Apparently it is not hall effect, but an optical sensor which includes, 3sensors and a PCB. So will update you when it has been replaced.

Looked at and test rode the UM36 torque sensor version today. It uses the same pedal sensor, but additionally a "caged" spring or elastomer contained radially in the chainring. There is a movement sensor to detect torque, and movement is limited to about 10 degrees. It does smooth down the ride a bit, and give a feeling of more control at low speeds, but it's not a major change, in my opinion. I could have upgraded to this for £50 but will not. I prefer the "full on" approach as soon as pedals are turned. plus, theres more to go wrong with torque sensor.

Jonathan.

 

[flecc]

Thanks Jonathan, I'll look forward to that information. It's good to hear that they are responding positively to a need for service attention, this having been such a weakness with some importers in this field.

 

[dickbris]

Jonathan, I have just joined the forum this morning when I had the same problem riding to work with my UM44. As your problem was last December I am interested to know if you found a satisfactory solution. For my case everything was fine until this morning, the battery was fully charged and the cutting out did not seem to have any particular periodicity, but did seem to be more prevalent under load, although it could still be slightly felt under normal running.

Any information gratefully received.
Dick

 

[Ian]

Dick, it might be an idea email Jonathan as from his member profile he hasn't been active on this forum since April. This can be done from his member profile page.

 

[coops]

Jonathan mentioned in an update in January that a new sensor fixed his bike's problem, maybe that's useful? I'd check with UM though, Dick, if you can, for a diagnosis of your bike's problem, in case its different .

I had an unfair advantage over Ian: I recalled having seen Jonathan's update at the time .

Stuart.

 

[Haku]

I've had a UM36 since 1st May, one with the new lithium battery and paid extra for the pedal torque sensor which I'm pleased I got it as it helps with pedalling at slow speeds, ie stuck in a traffic queue that moves in bursts as cars pull out onto a main road.

I've used the bike practically every day since I got it and most trips I've drained the battery through distance/time on it, about 7 times now since I've had it the power has cut-out completely when pedalling uphill, not steep hills and plenty of battery power left, the way I got the pedal sensor to 're-start' was to either stop completely then go again, or twist the throttle and make that take control for a moment and then let go of it and the pedal sensor kicks back in.

As it's happened to rarely I haven't taken this to be a fault, however I'm very careful now to switch the battery off when I've just gotten off and am pushing it because the pedal sensor sometimes is a little sensitive and the bike starts pulling away for a moment, one time it pulled right out of my hands and crashed on the ground . So either I switch it off or pull slightly on one of the brakes so no power can get to the motor.

 

[dickbris]

Thanks for the advice Stuart (and others). I'm talking to UM today anway as I had two spokes go on my way home last night (a definite fault!). Pity this had to happen as I was really enjoying the bike. I do a 6+6 mile commute each day in (very hillly) Bristol and am getting 18+miles to the charge.

I'll post any updated information when I know what is going on.
Dick

 

[dickbris]

Just to update that status of cutting out on my Urban Mover UM44. The bike went back to the shop in early July when two spokes failed on the back wheel, but it had an intermittent cutting out at the time under load at the time. The cutting out is believed to be due to loose connections, certainly all the shop did was to re-make and tighten the various connections. If it happens again I'll try this myself first but in this instance the bike had to go back for the back wheel repair. They also gave the bike the 2 month, post delivery check/maintainenance and the bike is now a dream to ride.

In passing I should say that the bike shop (Kings in Taunton) have been an aobsolute star, including picking up the bike from Bristol and dropping it back when it was fixed. Urban Mover support has been dismal, including taking nearly 2 months to get some replacement spokes and a new rim together, and delivered to the bike shop. At least they've agreed to re-start the warranty from when I got the bike back....least they can do after 2 months down-time.

 

[Ian]

In passing I should say that the bike shop (Kings in Taunton) have been an aobsolute star, including picking up the bike from Bristol and dropping it back when it was fixed. Urban Mover support has been dismal, including taking nearly 2 months to get some replacement spokes and a new rim together, and delivered to the bike shop. At least they've agreed to re-start the warranty from when I got the bike back....least they can do after 2 months down-time.

While it probably couldn't be claimed for under warranty it may be useful to know that St Johns Street Cycles in neighbouring Bridgewater are one of the few cycle shops in the country to stock spokes in almost any length, needless to say they also stock a full range of rims and other parts.

 

[BBB]

Urban mover really need to sort their after sales i have been waiting a year no to find where to get replacement batteries for the urban glider LA Batteries .
We all know electric bikes will have problems and the suppliers build this in to their price for warranty which is why you chose not just the cheapest bike on the market because you expect back up . but they really have none.

 

[flecc]

And made worse by them continuing to sell the bikes for which there could be no replacement batteries.

So not just bad service but cynical marketing.

I continued to look for the SLA battery size for that case for some while but drew a complete blank, it seems to be discontinued.
.

 

[Jonathan1]

UM Cutting again

Hi,

Sorry I was not there to answer the post from Dickbris. Unfortunately, I have the cutting out problem again on my UM36. I'm wondering if Dickbris can tell me which connections are suspect. The sensor connections are just very small push connectors (which I could imagine being unreliable). It's the power connectors that can be tightened, but I can't imagine it is a problem with power connectors. Since it can be overriden with the throttle, it seems to me that it is most likely to be the pedal sensor, or the connector for the pedal sensor. Maybe it's a really small signal for the pedal sensor? It's worse on very cold days, but the battery still has plenty of charge.
thanks,
Jonathan.

 

[dickbris]

UM cutting again.....yes mine too!

Hi Jonathan,
I don't have any details on which connections were re-made/tightened when it went into the shop. At that stage I only knew that the problem was no longer there when I got it back and I(we) assumed that it was this that had fixed it. Since then I have had a degree of downtime due to broken back spokes (another saga and another thread) but with those apparently fixed I am now using the bike again and guess what...it is starting to cut out intermittently again.

My fault appears to be the same as yours in that the throttle control seems to work OK but the pedal assist does not. As you say this is most likely to be due to the pedal sensor or the connections to it. As I am fed up with returning the bike, it being fixed for a few weeks then playing up again I plan to look at it myself and try and fix the problem. Of course I should not have to do this but.........

I'll post again within the next couple of weeks with progress.

 

[Jimblob]

Have read this thread with interest and wondered if your bike was now sorted?

 

[Jonathan1]

Problem seems to be fixed

Hi, I see that you sell them amongst others.....
I did two things, I unplugged and replugged the tiny pedal sensor connector 10 times in the control box, to clean the contacts. I then noticed that one of the large sprung contacts was sized. Looking at the underside of the battery, I saw that the sprung contacts have pushed the contact plates right up into the battery, (I have photos, that I can mail if you are interested, too large file size to attach to forum). Not very impressive. Keith Chamberlain at urban mover says he has not seen it before. I don't like those batterycontacts anyway, plus they let water into the control box if the battery is not present. So I have taken wires out of the top of the battery and fitted a maplin connector to the rear face of the control box. Much more positive, and will also keep the control box dry. It does mean I have to unplug a connector to remove the battery. Keith is going to send me another battery base FOC. Bike runs fine now. So my cutting out could have been due to very poor battery contacts or a poor sensor connector. The only doubt in my mind is that the problem started in the cold weather, but the weather is warmer now. I hope that I have fixed it and that it doesn't come back when it gets cold again.
regards,
Jonathan.

 

[dickbris]

Very interesting Jonathan. I'm looking at my bike this weekend so will bear your findings in mind. I have to say because the cutting out only seems to happen on in pedal assist mode I would suspect the sensor connections and not the battery issue as being the cause. In any event I hope you have fixed yours....and I can fix mine!

The battery connection appears a bad design fault (I also have a list of things that Keith at UM "has not seen before"). Your mod sounds good if I hit the same issue.

 

[Jonathan1]

More mods.

Hi,
will be intersting to see if you fix it with the connector. I agree that this seems to be most likely cause. I tested the bike yesterday in extreme rain. and all is fine, though water was still getting into the control compartment via the drain hole underneath. I have done more mods to completely seal it consisting of:
*** Reducing the size of the drain hole with a flat piece of plastic fixed on underneath with silicon sealant.
*** Applying a collar under the drain hole to guard against rain coming up into the new (smaller) hole
*** Removing one of the brake wires and making the cutout connection for both brakes come into the control box in one wire. This reduces the number of wires entering the front of the control box to 3 which is what the grommet is intended for. (4 wires were "stuffed" through mine)
*** Silicon sealing arount the front and rear cable entries to the control box
*** Putting the control electronics in the control box, at the top of the box, (propped up on a large rubber cork and wedged from top with a small piece of foam). This has two benefits,
1) provides some shock absorbtion to the electronics.
2) avoids the box sitting in the bottom, when if water gets in, the box can sit in the damp.
I live in Bishopston, where are you? If you want to have a look at it you're welcome, or I can email you photos if you are interested. My email is Jonathan.Lord@uwclub.net.
regards,