Wisper 705 Torque: Frequent Cut-Outs Requiring Controller Power-Cycle

[peter-3288]

My wife has a late 2016 Wisper 705 Torque with the 575Wh battery.

Recently she's been experiencing frequent power cut-outs, with the following symptoms:

• The battery indicator on the controller disappears completely ... i.e., the outline of the battery and the battery bars disappear, but the rest of the display is active
• Power assistance ceases
• The battery indicator reappears after a few seconds, and the battery bars slowly populate
• However, there is still no power assistance
• Power-cycling the controller restores power assistance until the next cut-out

Any ideas as to the possible cause of this fault? Symptoms would suggest that it is controller-related?

Thanks,
Peter

 

[Nealh]

You need to speak with the good guys at Wisper, the handle bar display sounds like the obvious cause esp if moisture has got inside.

 

[peter-3288]

Thanks for the response. I'd also wondered about water ingress into the display, since there was a small amount of condensation evident on the inside of the face of the display.

I'll point a hairdryer at the display unit for a few minutes to drive out any moisture. If there's been no permanent electrical damage, that might do the trick.

 

[Nealh]

Screen condensation is a give away and moisture will have settle on the pcb in side, most likely causing a short or damage to a component. A damp/wet pcb can cause all sorts of issues, moisture on any copper within can cause a short by way of a green track between components or a rust track may be formed acting in the same way.
Moisture may be able to be removed but any track/s formed causing shorts will remain as will the issue, either replacement or opening the display is the only option.
If it can be removed try placing the display in an airing cupboard or very warm place, sometimes placed in a bag with rice or silica bags can draw moisture out.

 

[Deleted member 25121]

I'll point a hairdryer at the display unit for a few minutes to drive out any moisture.

Better to put it in the airing cupboard for a day or two, you risk damaging seals and plastic with a hairdryer and a blast of hot air on the outside wouldn't displace moisture deep inside.

 

[peter-3288]

I used the hairdryer carefully for several minutes, without letting the display unit get too warm. The net result is that we managed about 10 miles before the first power cut-out. We'd also kept the bike inside overnight in a warm, dry house. So, this supports the hypothesis that the display unit is at fault due to moisture ingress, but it's not definitive.

As a digression, this has been a real problem bike. During three years of ownership, it's been off the road for several weeks in total with numerous faults. It's required a replacement motor, display unit, battery, and rear rack assembly, and there is still a minor problem with the charger. And this is for a well maintained bike with a light duty cycle -- a 5 mile round trip daily city commute and weekly leisure rides of up to 25 miles, with a 60kg rider. In contrast, my wife's previous eBike (a Smarta) was a model of reliability.

 

[Amoto65]

Unusual for a Wisper, I have had mine for over 2 years and over 2000 miles and it has been very reliable.

 

[peter-3288]

Unusual for a Wisper, I have had mine for over 2 years and over 2000 miles and it has been very reliable.

Yes, I'm sure it is unusual. The bike certainly gives the impression of being a generally good quality product, so I guess we've just been very unlucky. The frequent issues have meant that it has not been a good ownership experience.

Anyway, the display unit is now detached from the bike and sitting in the airing cupboard.

 

[Amoto65]

Hopefully you can get it sorted, David from Wisper is usually hovering around the site so I am sure he will be able to help you.

 

[peter-3288]

I've concluded that the display unit is likely not to be at fault. It's been throughly dried out and works fine until the fault starts to present. Instead, the fact that it takes ~10 miles for the fault first to emerge after a recharge suggests that it's a battery issue. Switching the battery on and off will temporarily restore power assistance.

The battery is a replacement for the original, provided by Wisper under warranty. The replacement battery looked used when we received it, so we can't be sure of its history.

I don't want to throw good money after bad on this bike, especially with something as expensive as a new battery, so I guess the next step is to get the battery checked out. Will our eBike (ex-Wisper) dealer have access to suitably detailed diagnostics, or should I send it back to Wisper for testing?

 

[Deleted member 25121]

I've concluded that the display unit is likely not to be at fault. It's been throughly dried out and works fine until the fault starts to present. Instead, the fact that it takes ~10 miles for the fault first to emerge after a recharge suggests that it's a battery issue. Switching the battery on and off will temporarily restore power assistance.

The battery is a replacement for the original, provided by Wisper under warranty. The replacement battery looked used when we received it, so we can't be sure of its history.

I don't want to throw good money after bad on this bike, especially with something as expensive as a new battery, so I guess the next step is to get the battery checked out. Will our eBike (ex-Wisper) dealer have access to suitably detailed diagnostics, or should I send it back to Wisper for testing?

The problem could be caused by the motor, display, controller or battery and I suggest taking the complete bike to a properly equipped bike shop or Wisper for a diagnosis, this may be a simple as experimenting by swapping each of these parts out.

By "controller" I'm referring to the high power electronics that applies the high currents to the motor, it may actually be built into the motor on your bike.

 

[Nealh]

A controller can cause power failure if it gets very hot (thermal cut out) and then once sufficiently cool will work again until heat is an issue again.

 

[Deleted member 25121]

A controller can cause power failure if it gets very hot (thermal cut out) and then once sufficiently cool will work again until heat is an issue again.

Also when electronic components fail at higher temperatures.

 

[peter-3288]

Thanks for the responses, folks. To summarise: it could be anything.

Is there a workshop manual available for this bike model that would assist me with conducting some diagnostics of my own?

 

[Deleted member 25121]

Thanks for the responses, folks. To summarise: it could be anything.

Is there a workshop manual available for this bike model that would assist me with conducting some diagnostics of my own?

Possibly there is within the trade but even that's unlikely.

 

[peter-3288]

Just to report back on this: a new controller unit (the one adjacent to the battery at the rear, not the front display unit) appears to have corrected the cut-outs. Not conclusive, but OK so far.

(So, that's controller unit #3 and counting, and another week off the road for the bike.)

With the new controller the rear light is always on when the battery is switched on. Bug or feature? Bug, presumably ...

 

[Deleted member 25121]

Pleased to hear that it's working OK now, thanks for the feedback.

 

[Nealh]

As years advance the software can change so it is possible that the light is always on and might be a safety feature. The fact the bike appears to be working is good news, problem with controllers is that you can only test for a few main faults once they have been exhausted the minute parts are beyond testing or replacement. Like wise with the display when one fogs up you /we can only suppose that it is at fault and that becomes harder when the issue may be due to something else.

 

[peter-3288]

With the new controller the rear light is always on when the battery is switched on. Bug or feature? Bug, presumably ...

Turns out it was a defective controller. Now replaced by new controller number four. Fingers crossed.

 

[Amoto65]

Wow that is unusual, hope you are sorted now.