Wisper Battery problems

kittykat

Finding my (electric) wheels
Sep 20, 2016
21
1
Ireland
I have a wisper 705 torque se with 575whr rack battery, Samsung cells.
The battery isn't charging now. When I plugged in the charger it would very briefly go red and then green immediately. The lights on the battery would flash as well. I've contacted wisper and they think it might be a bms issue.
I'm not sure if it's worth sending it for repair as I have the bike 3. 5 years. I had noticed some degradation issues already and the bike had cut out on a not so steep hill. Anyone replace the pack and bms themselves? I have a friend who's pretty handy. We have checked the charger voltage and it's 41.8v
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,986
Basildon
A new battery will get you another 3 1/2 years - cheaper than a new bike.

The fault could be something simple like a badly soldered wire. The BMS is unlikely to be faulty. more likely, there's a problem with the cells, so it's switched itself off. You won't know without opening it and checking it out with a meter. It's probably worth looking at the fuses and their holders first.

You can buy replacement cell-packs with BMS from Aliexpress, but you have to find one that fits in your case. You can use any battery you want if you don't want to pay for a Wisper one, though you might have to do some adaptation to make it fit. there are loads of rack batteries on Aliexpress.
 
Last edited:

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,093
8,212
60
West Sx RH
What's the battery voltage read ?
 
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Wisper Bikes

Trade Member
Apr 11, 2007
6,221
2,183
68
Sevenoaks Kent
I have a wisper 705 torque se with 575whr rack battery, Samsung cells.
The battery isn't charging now. When I plugged in the charger it would very briefly go red and then green immediately. The lights on the battery would flash as well. I've contacted wisper and they think it might be a bms issue.
I'm not sure if it's worth sending it for repair as I have the bike 3. 5 years. I had noticed some degradation issues already and the bike had cut out on a not so steep hill. Anyone replace the pack and bms themselves? I have a friend who's pretty handy. We have checked the charger voltage and it's 41.8v
If the voltage is still 41.8 the battery cells probably OK. If you arrange to get it to us we will probably be able to sort it out for you for a lot less than a new battery.

All the best, David
 
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kittykat

Finding my (electric) wheels
Sep 20, 2016
21
1
Ireland
If the voltage is still 41.8 the battery cells probably OK. If you arrange to get it to us we will probably be able to sort it out for you for a lot less than a new battery.

All the best, David
Thanks David, that's the voltage from the wall charger that we got when we were checking the charger to rule that out.
I'm looking for my voltage meter to test the battery
 
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kittykat

Finding my (electric) wheels
Sep 20, 2016
21
1
Ireland
A new battery will get you another 3 1/2 years - cheaper than a new bike.

The fault could be something simple like a badly soldered wire. The BMS is unlikely to be faulty. more likely, there's a problem with the cells, so it's switched itself off. You won't know without opening it and checking it out with a meter. It's probably worth looking at the fuses and their holders first.

You can buy replacement cell-packs with BMS from Aliexpress, but you have to find one that fits in your case. You can use any battery you want if you don't want to pay for a Wisper one, though you might have to do some adaptation to make it fit. there are loads of rack batteries on Aliexpress.
How much adaption would be required so you think?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,986
Basildon
How much adaption would be required so you think?
It depends on what you buy. Typically, a rack battery comes with its frame. You,ll have to transfer the controller to from itsold compartment to the new one. The frames always fit on the right side, but sometimes you have to make a spacer to clear the disc on the left side. Alternatively, you can fit a standard rack, then bolt the new battery's mounting plate to it.
 

Wisper Bikes

Trade Member
Apr 11, 2007
6,221
2,183
68
Sevenoaks Kent
Thanks David, that's the voltage from the wall charger that we got when we were checking the charger to rule that out.
I'm looking for my voltage meter to test the battery
Even though the battery is nearly 4 years old, if it’s not been left uncharged it should be OK. It’s certainly worth sending it to us to check. If it is the BMS it would cost a few pounds to put right. The only real risk is the £30 collection charge.

All the best, David
 

isla

Pedelecer
May 30, 2020
40
4
I have a wisper 705 torque se with 575whr rack battery, Samsung cells.
The battery isn't charging now. When I plugged in the charger it would very briefly go red and then green immediately. The lights on the battery would flash as well. I've contacted wisper and they think it might be a bms issue.
I'm not sure if it's worth sending it for repair as I have the bike 3. 5 years. I had noticed some degradation issues already and the bike had cut out on a not so steep hill. Anyone replace the pack and bms themselves? I have a friend who's pretty handy. We have checked the charger voltage and it's 41.8v
Hi, did you manage to get new cells? I seem to have the same problem with my battery.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
4,042
2,011
Telford
Hi, did you manage to get new cells? I seem to have the same problem with my battery.
It will probably cost as much to get your battery re-celled as a new one. When you get that problem, there might not be anything wrong with your battery. If you own a meter, it's easy to test your battery to find out what's causing your problem, otherwise probably best to send it to Wisper. If you live anywhere near Telford, you can bring it to me for testing, which won't cost anything.
 

PaulM

Pedelecer
Oct 29, 2017
65
15
60
Portsmouth
Hi, did you manage to get new cells? I seem to have the same problem with my battery.
I am looking to sell my Wisper 575WH rack battery, having ordered a 700WH one. I bought the bike Nov '22, mileage is about 550 and the battery has never been left in a discharged state. I'm thinking of advertising it for £180 plus the delivery charge if delivery required. Let me know if you are interested.
 

isla

Pedelecer
May 30, 2020
40
4
It will probably cost as much to get your battery re-celled as a new one. When you get that problem, there might not be anything wrong with your battery. If you own a meter, it's easy to test your battery to find out what's causing your problem, otherwise probably best to send it to Wisper. If you live anywhere near Telford, you can bring it to me for testing, which won't cost anything.
Thank you for your kind offer, I may be down your way in the spring, if so I will give you a shout. The battery is showing 38.2, I know it should be about 42. I held in the power button for a while in the hope it might have been awakening it from hibernating. The battery indicator shows full now and green lights blink 3 times before going off, strange as the charger shows it isn’t charging the battery but I only had one green light yesterday. When I try putting battery into the bike the display only comes on for a second. Just as well I have another bike to use. I’ve had 4 bike batteries over the years and none have failed like this Wisper. Pile of crap if you ask me, so much for hibernation mode when it clearly didn’t work.
 

isla

Pedelecer
May 30, 2020
40
4
I am looking to sell my Wisper 575WH rack battery, having ordered a 700WH one. I bought the bike Nov '22, mileage is about 550 and the battery has never been left in a discharged state. I'm thinking of advertising it for £180 plus the delivery charge if delivery required. Let me know if you are interested.
Thanks but it’s a bit expensive for a 2nd hand battery with no warranty. Mine was never left in a discharged state either or so I thought. I believed 4 month in hibernation was fine. At the moment I have another bike to use so I will try to find out what’s wrong with the battery first before I decide what to do.
 

Wisper Bikes

Trade Member
Apr 11, 2007
6,221
2,183
68
Sevenoaks Kent
Hi Isla!

it reads as if you left your battery in a discharged state for too long. We’d be very pleased to check it for you free of charge if you’d like to get it to us? It may be something we can resolve.

His old is the battery?

All the best, David
 
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PaulM

Pedelecer
Oct 29, 2017
65
15
60
Portsmouth
Thanks but it’s a bit expensive for a 2nd hand battery with no warranty. Mine was never left in a discharged state either or so I thought. I believed 4 month in hibernation was fine. At the moment I have another bike to use so I will try to find out what’s wrong with the battery first before I decide what to do.
Fair enough though they are £500 new. Looks like I will need to find a local buyer since shipping is a problem. £150 if you change your mind and can rendezvous within 100 miles of Portsmouth. I am getting around 50 miles on a charge when using power level 3.
 
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isla

Pedelecer
May 30, 2020
40
4
Hi Isla!

it reads as if you left your battery in a discharged state for too long. We’d be very pleased to check it for you free of charge if you’d like to get it to us? It may be something we can resolve.

His old is the battery?

All the best, David
Thanks David much appreciated that’s a better response than the phone call I had with your premises . I will pop the battery in when I’m next in the area if I haven’t got it sorted by then.
 

isla

Pedelecer
May 30, 2020
40
4
Fair enough though they are £500 new. Looks like I will need to find a local buyer since shipping is a problem. £150 if you change your mind and can rendezvous within 100 miles of Portsmouth. I am getting around 50 miles on a charge when using power level 3.
I’ve sent you a PM
 
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Toddy

Just Joined
Mar 25, 2024
2
1
Fair enough though they are £500 new. Looks like I will need to find a local buyer since shipping is a problem. £150 if you change your mind and can rendezvous within 100 miles of Portsmouth. I am getting around 50 miles on a charge when using power level 3.
Is the battery still available