Wisper battery decline - how does it work?

allen-uk

Esteemed Pedelecer
May 1, 2010
909
25
Michael: sounds very like my problem with my Wisper, and the warm room doesn't help either. Mine is kept in a centrally-heated house, but give it 3 minutes out in those bitter cold winds and it loses its 'oomph'. I'm sure David/Wisper will sort it out if it IS a duff battery, but in my case in certainly was the cold - now it's around 10°C in the south of England all is back to normal.


Allen.
 

michael sullivan

Finding my (electric) wheels
Jun 25, 2010
17
0
Michael: sounds very like my problem with my Wisper, and the warm room doesn't help either. Mine is kept in a centrally-heated house, but give it 3 minutes out in those bitter cold winds and it loses its 'oomph'. I'm sure David/Wisper will sort it out if it IS a duff battery, but in my case in certainly was the cold - now it's around 10°C in the south of England all is back to normal.


Allen.
Hi Allen thanks for that about 11 degs here today went for spin and I think you are rite but I think the battery down in power done 30 KLMS only two lights left dats with me doin most of pedeling in mid power on controler. I will have to have it chequed out by trying another battery.
 

allen-uk

Esteemed Pedelecer
May 1, 2010
909
25
Michael: do keep on posting updates on this one, as there is always a chance that Wisper went through a 'bad battery' phase in the middle of last year, and if you've got one, I might have one too!

Allen.
 

Wisper Bikes

Trade Member
Apr 11, 2007
6,282
2,252
69
Sevenoaks Kent
Yes, please let me know how it goes, of the 1000's of bikes sold last year in the UK we have had a few batteries that are not performing as well as they should. We would rather swap it out than you feel dissatisfied. It's really no problem, we would simply return it to Reva in Germany for reconditioning.

All the best

David
 

michael sullivan

Finding my (electric) wheels
Jun 25, 2010
17
0
Yes, please let me know how it goes, of the 1000's of bikes sold last year in the UK we have had a few batteries that are not performing as well as they should. We would rather swap it out than you feel dissatisfied. It's really no problem, we would simply return it to Reva in Germany for reconditioning.

All the best

David
Hi again David I was out on bike yesterday it was a nice day here in Ireland 11 or 12 degs ,but I stil only got just under 30 KLMS and bearly 2 lights left ,so I will call to Marty an see can he sort it out .I was in hard luck last year when I got the bike ,Marty changed 3 battries for me .But I still think I could have one of the ones that gave trouble, thanks David for getting back to me , very gratefull to all , Michael
 

Wisper Bikes

Trade Member
Apr 11, 2007
6,282
2,252
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Sevenoaks Kent
No Problems Michael,

Please keep me informed.

We will need some more details about the way the bike is being ridden, terrain and weights. I understand you are achieving 30km from 60% of the battery in temperatures of 11C. It would be interesting to see what you get out of a full battery discharge. If you do achieve 50km it would not seem to be anything wrong with the battery especially in cold weather. There may be some other factors that we need to consider.

All the best

David
 

michael sullivan

Finding my (electric) wheels
Jun 25, 2010
17
0
Hi David just back from my longest cycle this year I done 45.9 KLMS on fairly level roads some small hills , I done most of the pedeling on mid power ,about one tenth on trottle and a little more on hi power just made it home with the last light flashing.Fine if you say 50 KLMS is about right.The temp to day is 15 degs C. so weather not to bad. I an just under 12 stone weight,and fairly fit as I said done most of journey on pedal assist on mostly mid power .If you think this is about the go of the battery, can you tell me if there is a 15 amp battery coming out soom ,again thanks for replying to me , very grateful .Regards Michael
 

flecc

Member
Oct 25, 2006
53,154
30,570
Generally no, a specific LiFePO4 charger is best.

The reason is that the cell voltages of the two are different:

Li-ion 3.7 volts per cell nominal.

LiFePO4 3.3 volts per cell nominal.

There's no absolute answer though, since some
LiFePO4 batteries have additional cells to make up for the lower voltage, leaving the battery with a similar voltage to Li-ion manganese etc.

Therefore best to use the guidance of your battery supplier.
.
 
Last edited:

Wisper Bikes

Trade Member
Apr 11, 2007
6,282
2,252
69
Sevenoaks Kent
Absolutely, if you use a different charger from the one recommended or supplied by the battery manufacturer, you risk damaging the battery and voiding your warranty.

As Flecc quite correctly says, you may find another charger works well but it would be far less of a risk to use the one reccomended.

Regards

David
 
Hi, hope you don't mind me joining this thread, but I have a battery problem. It's the same high capacity battery for the Wisper 905 City, but have found that it will no longer charge with the supplied charger.

The battery is completely flat, as I haven't run it over the winter. Was charging fine up until October last year. What I see is the charger dispalys an orange light, the fan flicks over, then the light turns green and no charging occurs.

Is the fault with the battery, or the charger?
 

Wisper Bikes

Trade Member
Apr 11, 2007
6,282
2,252
69
Sevenoaks Kent
Hi dkohara

It could be either, it is best to contact your supplier or failing that Steve in support. Either way we will fins a solution for you.

All the best

David
 

michael sullivan

Finding my (electric) wheels
Jun 25, 2010
17
0
battery for wisper

Hi dkohara

It could be either, it is best to contact your supplier or failing that Steve in support. Either way we will fins a solution for you.

All the best

David
Hi Dave any news on a 15,amp battery comming out for the Wisper bikes.
Cheers Michael
 
I've been talking via email with Steve, who tells me that my battery has been irreparably damaged by leaving it uncharged over the winter. There is nothing about this in the Wisper 905se City manual under 'Battery Care', other than to offer guidance for keeping it in 'top condition'.

A new battery is £530. :(
 

Wisper Bikes

Trade Member
Apr 11, 2007
6,282
2,252
69
Sevenoaks Kent
Hi DKOhara

Steve is correct, all Li Po batteries must be kept charged at about 2/3 full over any long period of inactivity and re-charged every 6 weeks or so to keep the battery in tip top condition. If is left flat for even a relatively short period you can seriously damage the cells.

I will look at the wording in our manuals.

I will PM you.

Regards

David
 

andrewgardner

Pedelecer
Jul 29, 2009
66
4
Hi

I would buy a battery from BMS battery in china cost including delivery

approx £220 including charger you can pay by paypal so your money is secure

36V 15Ah Li-Ion Alloy Shell Battery Pack - BMSBATTERY

This will mount on rear rack you will have to wire into controller

Frank
I think a Wisper battery will be better quality, but if it dose go wrong pop round to the shop you bought it.
If a BSM battery goes wrong it is a slow boat to China.

You pays your money----
 

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