Confusing fault

davidk.

Finding my (electric) wheels
Apr 27, 2021
7
0
Hello, and thanks for letting me join this forum. I have since 2017 owned a Wisper 705, which has given excellent service, covering around 900 miles. Some weeks ago i noticed that the screen display showed a full charge after 18 miles? i took the battery out and checked and only 1 green and 1 red light showed. Also the + and - buttons on the controller were not working well i had to press really hard. I fitted a new controller and it worked fine but still showed full battery when only 1 green and 1 red light showed. Is the battery is failing? Using number 4 assist it struggles to move the bike if i use number assist 1 it goes well. Even from 2 years old it would fail and i had to back pedal fast to get the motor running. I'm confused any idea appreciated, thank you.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
There's probably a setting in the LCD for 24v or 36v and forwhatever reason, it's now set to 24v. have you been fiddling with it?

If that's not the reason, there were a batch of faulty LCDs on that model of Wisper at about that time. It might be worth giving Wisper a call to see what they have to say.
 
Last edited:

Danidl

Esteemed Pedelecer
Sep 29, 2016
8,608
12,253
73
Ireland
Hello, and thanks for letting me join this forum. I have since 2017 owned a Wisper 705, which has given excellent service, covering around 900 miles. Some weeks ago i noticed that the screen display showed a full charge after 18 miles? i took the battery out and checked and only 1 green and 1 red light showed. Also the + and - buttons on the controller were not working well i had to press really hard. I fitted a new controller and it worked fine but still showed full battery when only 1 green and 1 red light showed. Is the battery is failing? Using number 4 assist it struggles to move the bike if i use number assist 1 it goes well. Even from 2 years old it would fail and i had to back pedal fast to get the motor running. I'm confused any idea appreciated, thank you.
I suspect the battery. As the battery wears, lumps of material in each cell become detached from the main block, and the device charges quicker, but with very limited capacity. When the terminal voltage reaches the plateau, the charger stops. The battery indicator is probably giving a more accurate measurement of the stored energy
 

davidk.

Finding my (electric) wheels
Apr 27, 2021
7
0
I suspect the battery. As the battery wears, lumps of material in each cell become detached from the main block, and the device charges quicker, but with very limited capacity. When the terminal voltage reaches the plateau, the charger stops. The battery indicator is probably giving a more accurate measurement of the stored energy
Hello, many thanks for your reply and i think you could be onto to something regarding the cells in the battery. I've noticed that it will charge in about 25 mins from being almost flat. Perhaps this is causing the display to be inaccurate too. I will order another battery but it's a week wait for one! Thanks again.
 

davidk.

Finding my (electric) wheels
Apr 27, 2021
7
0
There's probably a setting in the LCD for 24v or 36v and forwhatever reason, it's now set to 24v. have you been fiddling with it?

If that's not the reason, there were a batch of faulty LCDs on that model of Wisper at about that time. It might be worth giving Wisper a call to see what they have to say.
Hi, thanks for your thoughts on this, i cannot find a voltage indicator on my 705 and out of desperation i have pushed lots of buttons, the hand book is not too good on what is displayed. I will go for another battery i think. Thanks.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
Hi, thanks for your thoughts on this, i cannot find a voltage indicator on my 705 and out of desperation i have pushed lots of buttons, the hand book is not too good on what is displayed. I will go for another battery i think. Thanks.
So you might have two batteries and still no working bike.
 

davidk.

Finding my (electric) wheels
Apr 27, 2021
7
0
Did you talk to Wisper about their bad batch of LCDs?
Hi, i haven't spoken to them, and the new display seems to function ok, but i still cannot get an answer as to why the display shows a full battery when the on board battery indicatorsshow empty!
 

davidk.

Finding my (electric) wheels
Apr 27, 2021
7
0
I'm no genius and very bad at logic, but could it be that you have a faulty LCD?
Hi, i could well be a faulty LCD, the shop has offered to send another, so i'll probably go down that route. Thank you.
 

davidk.

Finding my (electric) wheels
Apr 27, 2021
7
0
If you had contacted Wisper, you could probably have got it for nothing.
Hi , as the original was four years old, and one of the buttons was playing up, i opted for a new one anyway, but i still cannot get a definitive reason for the fault. Do you know Wispers HQ, the one in Kent is helpful but not able to solve the problem. The one in Germany is out of contact, emails will not connect. Thanks.
 

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