Wisper 905SE cutting out randomly

[Glen10]

Hi,

I have a Wisper 905SE. It's about 4 years old. I've not massively used it much over the last year as it developed a problem of cutting out randomly. I didn't really need it so didn't bother doing anything about it. We've recently moved and now I could really do with using it. I went for a cycle this morning and it works for about 100m, then everything electric cuts out. The screen is blank and when I try to hit the power button nothing works. After about 5mins of cycling (or stopping by the road scratting my head), I then hit the power button and it works again. Sometimes it lasts 10meters, sometimes it lasts about 400meters. Any ideas? It doesn't seem to be related to bumps in the road or anything like that. It also does it whether I'm using just the throttle, or just peddling! It does it if I'm going downhill, or uphill. Any ideas would be hugely helpful?

 

[cyclebuddy]

It's about 4 years old...
I've not massively used it much over the last year...
everything electric cuts out. The screen is blank...

It sounds to me as if your battery is dead/dying and hitting the low-voltage cut-out. Age and dis-use can often do that. It would be worth fully charging it and measuring the voltage with a multi-meter to see if there's still any worth-while life left in it - taking a ride as far as you can, and then measuring the voltage again to see if it's collapsed.

 

[Glen10]

It sounds to me as if your battery is dead/dying and hitting the low-voltage cut-out. Age and dis-use can often do that. It would be worth fully charging it and measuring the voltage with a multi-meter to see if there's still any worth-while life left in it - taking a ride as far as you can, and then measuring the voltage again to see if it's collapsed.

Hi, that's really helpful. I fully charged it before my cycle this morning but it cut out 100m into the cycle. I'll get a multi-meter and see if that can shed some light. I was worried it would be the battery, they can cost almost as much as the bike itself!

 

[vfr400]

Hi, that's really helpful. I fully charged it before my cycle this morning but it cut out 100m into the cycle. I'll get a multi-meter and see if that can shed some light. I was worried it would be the battery, they can cost almost as much as the bike itself!

You need to measure the battery's voltage as soon as you take it off the charger. that will give a big clue as to where your problem might be. measure it again after you bike starts cutting out.

When the display goes off at the same time as the cut-out occurs, it means that the voltage from the battery has been interrupted. It could be a connection issue.

 

[Glen10]

You need to measure the battery's voltage as soon as you take it off the charger. that will give a big clue as to where your problem might be. measure it again after you bike starts cutting out.

When the display goes off at the same time as the cut-out occurs, it means that the voltage from the battery has been interrupted. It could be a connection issue.

Hi, Thank you for that. My battery has a little button you can press to see how much charge is in it. It shows as full at the moment. But if the battery has an issue then that might not be working right either.

 

[sjpt]

Hi, Thank you for that. My battery has a little button you can press to see how much charge is in it. It shows as full at the moment. But if the battery has an issue then that might not be working right either.

When a battery is almost dead it still usually charges to near the full original charge voltage; it's just as soon as current is drawn the voltage sags alarmingly. Most battery charge displays (on the battery or on a separate LCD display) show the voltage. Even with a fairly healthy battery the display can drop a couple of bars out of 5 when going up a hill; you probably can't see that from the lights on the battery itself. Most displays show full until quite a bit below the full charge/no current voltage.

 

[vfr400]

Hi, Thank you for that. My battery has a little button you can press to see how much charge is in it. It shows as full at the moment. But if the battery has an issue then that might not be working right either.

Don't waste time and effort. Just do the measurements.

 

[Tiggy]

H

Hi,

I have a Wisper 905SE. It's about 4 years old. I've not massively used it much over the last year as it developed a problem of cutting out randomly. I didn't really need it so didn't bother doing anything about it. We've recently moved and now I could really do with using it. I went for a cycle this morning and it works for about 100m, then everything electric cuts out. The screen is blank and when I try to hit the power button nothing works. After about 5mins of cycling (or stopping by the road scratting my head), I then hit the power button and it works again. Sometimes it lasts 10meters, sometimes it lasts about 400meters. Any ideas? It doesn't seem to be related to bumps in the road or anything like that. It also does it whether I'm using just the throttle, or just peddling! It does it if I'm going downhill, or uphill. Any ideas would be hugely helpful?

I had this problem. It was because the battery kept slipping back out of the connectors. Not visibly so though. I could fix it temorarily by giving the battery a push back in. I had a look inside the bit that the key goes into and found the plastic bits that hold the key had broken and the key latch thingy that holds the battery in was wobbly. I have ordered a new part. Still waiting but will report back.

 

[Tiggy]

New part fitted. Didn't help the issue.

I figured it must be the battery/bike socket/plug isn't quite meeting. I put some copper wire into the battery socket holes held in place with duct tape to help bridge the gap and it works fine now.