Wisper works 905e battery replacement

[hawkwind]

Hi, i have a Wisper works 905e bought in 2007 with the 36v 10ah lion battery.
Due to illness i have been unable to ride the bike for the past couple of years and with one thing and another the battery was not charged during this time.
I did not expect it to work but tried charging it anyway, went back to work for a few hours and when i came back the light had gone green, but as expected the battery would not power the bike.
I have tried putting some power briefly to the bike, it powered up and the motor turns fine.
The fuse on the battery is also ok so i would assume that the battery is shot.
Reconnecting the charger and the light goes green immediately.

Is there a cheaper alternative than buying a replacement from Wisper as with the price of a replacement for a 4 year old bike it would probably be as well to buy a new bike.

Thanks.

 

[rog_london]

Even if you'd looked after it you would be lucky to have much left after four years.

The problem with a replacement would of course be the fact that it wouldn't fit in the carrier. There isn't really anywhere else on the 905 to mount an alternative.

If the bike hasn't had a lot of use it's still a good one from your viewpoint, and as long as you accept that the whole of its value would be in any new battery you bought, I think that's probably not a bad route to follow.

The 14Ah battery would cost you around £500, assuming Wisper still do the £40 trade-in on the old one. You'd get far more value for your money doing that than you would by buying a new bike, IMO. I don't recall the price of the 10Ah one, but probably a good £100 less.

Rog.

 

[hawkwind]

Thanks Rog.
A bit of a dilemma, yes the bike is still not in too bad a condition so maybe a replacement battery may be the best option.
Then again i could get a new Cyclamatic for not much more, the people who have this bike seem quite happy with their bike for the money.
Maybe just flip a coin to decide lol.

 

[Deleted member 4366]

If you're technically competent, you might be able to dismantle the battery box and remove the actual battery. Inside will be the battery BMS and the actual cell pack. There's a few suppliers that can provide batteries in a range of sizes and shapes. If you go this route, take some photos and measurements of the cell pack and report back and maybe we can help you further. The battery is scrap anyway, so you've got nothing to lose.

 

[hawkwind]

Hi and thank you.
I will have a look when i finish work tomorrow morning.

 

[hawkwind]

Each individual block is 28mm x 70mm
The whole area for the full pack to fit is 100mm wide x 243mm long and 70 mm deep although the depth could be increased as there is a dense foam protection on the outer case for the pack about 23mm deep.

I did try to remove the pack but it is fixed solid in place, i assume it is glued so i did not want to try and force it.

Electrics are definitely not my strong point so this looks like it would be beyond my capabilities if there is any complicated wiring procedure.

 

[Chris Maluszynski]

I just found this thread.
I have the exact same issue with a dead Wisper 10ah battery.
Also not very electrically savy, but definietly willing to try if I'm told how not to electrocute myself.

I supposw Hawkwind gave up the project? Or did you go through with it? If so, could you please tell me where you got the replacement cells and what you did?

D8evh, if you can give any advice and point to where to order cells in the right sizes, let me know.

Cheers, Chris

 

[Alphageek]

Just found this thread too... I'm in the processing of replacing the battery pack in the inside of my battery case. I'll let you know how I go.

 

[Chris Maluszynski]

Great Alphageek! Look forward to hearing about your project. I'll follow you!