Wisper battery

[Kabadi]

I bought my 905 a few months ago. It has the 14Ah battery

I'm after some advice/experience from other Wisper riders. I'm not sure that my battery is performing as it should. I certainly don't get anything like the performance given on the Wisper website. (i.e 50+ miles)

From a full charge, I get to about 4 miles before the green light starts to go out when the motor is working. By six miles, the amber light is also going out when motor is working. By 10-12 ish miles I can tell that the battery is going flat as the assistance is declining noticeably. However when I stop, amber and green come back on!

I ride a fairly flat route on a tarmac cycle path, with off road activated but never using the throttle. I have made sure that my tyres are properly inflated. I am a bit heavier than the road test rider on Wisper's road test (17 stone) but feel this can't be the sole reason.

Is this consistent with other users? I have contacted Wisper who will happily carry out a capacity test on my battery but that means paying to post my battery and communting without it for a week. I don't want to do that just to find out my battery is 'normal'.

Thanks for any advice

 

[eddieo]

Have you conditioned the battery from new? have you ridden the battery to flat yet? and what kind of mileage was that? While waiting for some expert help....It is normal for the battery to recover, and for the green and yellow light to come back on after it has been put under strain.

it sounds like you may have a problem but I am not sure....

 

[Kabadi]

The bike I bought was a display model in the shop I bought it from so I didn't have the battery from brand new.

My daily commute is 12 miles by which time it seems fairly flat. I havn't then riden it the next day without charging in case it is completely flat before I get home. Maybe I should just take the risk to get a definate millage to completely flat. How will I tell if it is completely flat? Will it completely cut out?

 

[eddieo]

The bike I bought was a display model in the shop I bought it from so I didn't have the battery from brand new.

My daily commute is 12 miles by which time it seems fairly flat. I havn't then riden it the next day without charging in case it is completely flat before I get home. Maybe I should just take the risk to get a definate millage to completely flat. How will I tell if it is completely flat? Will it completely cut out?

Not sure........seeing as we are still waiting for an expert. "fairly flat" is not flat. So time it so that it is nearly flat when you reach home? say on a friday night and then Saturday morning ride around locally till flat. charge fully then repeat this. you are supposed to do this 2 or 3 times when new to condition the battery.

where did you buy it from, are they a wisper dealer,what have they had to say?

 

[winterdog]

I think this is normal if you are using throttle all the way i reckon
using full no throttle (and set to HI) i reckon 40 ish(if i was in off road mode)
i normally recharge after 20 miles when i get to work, but i have always measured the battery when not under load as it can be in the amber after 4 heavy ish miles
david

 

[Kabadi]

I don't use the throttle. 40 ish is more like I'd expect and be happy with.

I'd be grateful to get anyone elses experience?

 

[monster]

you can expect about 15-25wh per mile depending on how much power you use. whats the voltage? if its 24V and 14Ah the that gives you 504wh. which would give you about 13.4 miles range. if its second hand then it may be even less than that. never believe the manufacturers range "specifications" they are just made up, probably based on lance armstrong riding and only using 1% throttle

whats the point in riding an electric bike and not using the throttle?

 

[Kabadi]

The point (at least on Wisper bikes) is that they have pedal assist which is independent from the throttle.

 

[torrent99]

The point (at least on Wisper bikes) is that they have pedal assist which is independent from the throttle.

Ok a few factors here that could be contributing to this:
a) It was ex-display. So we don't know how well the battery has been treated before you got it, or exactly how old it is. (David from Wisper might be able to tell you if you have the serial number).
b) Your weight is on the high side.
c) You don't say how much stopping+ starting is involved in your route. Starting from a standstill places a huge strain on the battery to get you up to a reasonable speed (even more so if you are heavy).
To reduce the strain you need to start off with lower amounts of throttle & then increase the throttle as you build up speed. As my battery is getting older, I'm needing to marshall power a little bit in this way rather than just slamming on maximum throttle. This really helps battery life.

From my more conservative calculations maximum range on a new 36V 14Ah battery @ about 30Wh/mile (which is roughly what I get on throttle only in London city traffic) is about 16 miles, so you'd expect to see a drop off in performance at the 12 mile mark.

Those 40+ mile figures are for cyclists providing a good deal of input themselves and never having to stop! (Wisper are pretty honest about their testing criteria for the range figures they provide)

Cheers

Steve

 

[Kabadi]

Thanks for the feedback.

a) Yes, this is a concern. Where is there serial number located on the battery?
b) Agreed. I have nothing more to say on this!
c) Very little starting/stoping involved. I am definatly putting in input myself.

 

[eddieo]

serial number of bike is underneath the crank

 

[Straylight]

A while ago, David from Wisper mentioned that they had bought some very slow rate chargers that they were willing to loan to customers, so that they could refresh their batteries. I think this may well be worth a go as it certainly sounds like your battery isn't holding enough charge.

My commute is 12.5miles each way, I ride mainly in off road mode at full throttle, albeit with few stops, averaging around 17mph. This, it would seem, makes for quite a high discharge rate, and yet on days when there is no significant headwind, I can arrive with all three power lights still on. If I do the entire round trip without recharging in the middle, then I'm pretty much down to red light only at the end. I have to say though, that I've not noticed a significant lack of power even then, and I do tend to lean on the motor a bit more on the return journey.

 

[Straylight]

serial number of bike is underneath the crank

This may be model dependant, as my frame no. is embossed just below the Logo on the front of the bike i.e. just above the forks, and the battery s/n is engraved on the very underside of the battery. I have a 2008 version of the 905se btw.

 

[eddieo]

I suppose its a bit like car manufacturers fuel consumption claims.

I am carrying out tests on my battery this week.(rained off today) It is a 14 amp wisper 905SE as well. I am also 17 stone. so far 2 rides of 8 miles. de restricted all the time. I pedal all the time, and only use additional throttle on inclines. just had a look and all 3 lights on, but I suspect the green will go once I start peddling......as it was dim on my return yesterday

I expect to get at least one more circuit out of it (8 mile) maybe 2? who knows! It will be interesting to see what's left.....

so the general thoughts on here so far seems to be about a 30 miles range more or less? But I guess this would be for an average weight person......My wife on her 14 amp 705 sails up hills without hardly changing gear, while I am in low gear full throttle frantically trying to keep up........

 

[Straylight]

Yes, 30 miles - maybe a little more, would be my estimate. I've never run it to cut out though - too lazy to get stuck without power, and have to lug the thing home I weigh in at around 14st btw, though I do carry quite a heavy pannier as well.

 

[Fat Elvis]

I had a simarler problem to this on mine, It would start cutting out as well. It turned out to be the controller box. It did take a while to get to the bottom of it. It was also my main transport but the guys at Oxford ETS loaned me a bike while they got to the bottom of my problem.

 

[Wisper Bikes]

Battery

Hi Kabadi

The first thing to do is to let us know the serial number and we can let you know how old it is. If it has been left for several months without half charging the battery the range will certainly have been effected.

We would be happy to put it onto the trickle charger for you to see if that helps. I think though you will need to send it to service to have it checked out. Where did you buy it from? Does it have Wisper printed on the frame?

Best regards David

 

[Toby]

motor only riding wisper 905.

Hi I very recently purchased a 14ah wisper eco running on 1/4 battery and got 3.9 miles so times 4 = 15.6 miles.
I just traded in for a sport with full battery and will test ride when the rain stops tomorrow but expect 15.6 motor only.
I weigh in at 18stone so I think us heavier riders can expect the figures above.

 

[Kabadi]

Is this the serial number? (can be seen in attached photo)

260240A0-002
B/E 0015


Second photo shows label on side of battery. Curiously it says 36v when everything I read on the website says they are 37v

 

[Straylight]

Yep, that's what I took to be the serial no.

36v seems to be the nominal rating, but when they're fully charged, they actually output close on 42v.