wisper strange battery issue!

[al.b]

Hi Guys I hope you are all keeping safe. this refers to a wisper 575 w battery app 4 years old. It has not been overworked and has been well looked after over the years. I put the battery to sleep(Samsung celled with hibernation mode)in January 2020 and decide over the weekend to start to use my bike on a very limited ride( I am 70 and not fit) I checked the battery before fitting:
all lights green and when connected to the charger it also showed fully charged status. Fitted to the bike and then it only showed 3/4 full and when I ran the motor a while(no load) it showed a drain on the display. Took it of again checked the battery(all green lights) connected to the charger all green. I have measured the voltage at 38v from the battery but I am struggling to find an answer. Any pointers would be helpful or is the battery by age finished? I have always ensured it remain fully charged since having it. I know batteries do deteriorate over time and loose capacity but would of thought this would show on the battery display itself.

 

[cyclebuddy]

I have measured the voltage at 38v from the battery

A 36-volt battery should charge to between 41 and 42 volts when full.

I have always ensured it remain fully charged since having it.

Ideally, when the battery is not being used for a week or more, it should really be left at a middling charge; most here suggest around 37/38 volts as being best. Leaving a battery at full charge for a protracted period of time stresses the cells.

I know batteries do deteriorate over time and loose capacity but would of thought this would show on the battery display itself.

A battery getting towards the end of its useful life can look like it's holding a full charge, but as soon as you apply a load, the cells sag badly and the voltage collapses... it has no grunt left to give.

It does look as if that might be happening to your battery. But 4 years of active life isn't too bad. You could check that the charger is outputting 42 volts, and double-check the battery voltage again as soon as you take it off the charger.

 

[Jonah]

You might find that it you go for a short ride to discharge the battery a bit and then plug it back in to the charger, it will then start to charge again. If there are any unbalanced cells, this should then get sorted. This may not help, but it might be worth a try.

 

[Nealh]

41.5v minimum usually for a battery in good health.
If poss try and cycle the battery a few times to see if things improve, use a meter for proper voltage readings not led lights on a display or battery.

 

[Andy-Mat]

41.5v minimum usually for a battery in good health.
If poss try and cycle the battery a few times to see if things improve, use a meter for proper voltage readings not led lights on a display or battery.

What is really needed is a dummy load that draws say about 10 amps from a nominal 36 volts, to see if the voltage collapses or not, due to damaged cells.
So a high wattage resistor of between 3 and 3.5 amps. Current will vary depending upon the actual battery voltage at the time when tested.
Ohm's law is very easy to work out!
What I have done in the past, is to use mains voltage lamps, several wired in parallel till that approximate resistance I needed is achieved. They are easy to find and very cheap! Also, the "hot" bits are in a glass envelope and less likely to cause burns!
Using the same wattage/voltage makes it easier to calculate the total resistance in parallel.
I just checked a 200 watt 240 volt floodlight lamp and it has 24 Ohms cold (unsurprisingly of course!)
So 2 in parallel would be 12 Ohms, 4 would be 6, 8 about 3 Ohms.
There is a slight change in resistance upwards as the filaments heat up, but they will still stay dark of course.....
So a cheap pack of 8 floodlight lamps (I do not know the name in English, but they are straight, have porcelain pieces at each end holding the contact), soldered together, would be a cheap and relatively safe dummy load. Measuring the current and the voltage simultaneously, would of course give the possibility calculating the actual "HOT" resistance more accurately if needed.
Never leave such a test rig running unattended, as fire is still a possibility, and also draining the battery too far down, in spite of an active BMS, may happen for some obtuse reason....
Regards
Andy

 

[Wisper Bikes]

Hi Al, sorry not to have been about lately. Have you resolved the battery issue?

If not please email Claud at support@wisperbikes.com, I have spoken to him about the issue and we can reset the battery for you.

All the best, David

 

[al.b]

Hi Al, sorry not to have been about lately. Have you resolved the battery issue?

If not please email Claud at support@wisperbikes.com, I have spoken to him about the issue and we can reset the battery for you.

All the best, David

Hi David, thanks for your reply, I have tried agin this morning having only travelled less that 1mile and the battery gave up! put it on charge, the light on the charger is showing green when initially plugged in and remains on green but the battery indicator on the battery shows red and only one green. I am assuming the battery didnt survive the last hibernation cycle and has probably reached its last gasp. I will email claud about it today, I know you have been busy and did email you last year without reply but thnaks for your support and those of the forum guys

 

[Wisper Bikes]

Hi David, thanks for your reply, I have tried agin this morning having only travelled less that 1mile and the battery gave up! put it on charge, the light on the charger is showing green when initially plugged in and remains on green but the battery indicator on the battery shows red and only one green. I am assuming the battery didnt survive the last hibernation cycle and has probably reached its last gasp. I will email claud about it today, I know you have been busy and did email you last year without reply but thnaks for your support and those of the forum guys

Hi Al, never say die!

If you would like to send it back to us, we will see if we can revive it. It's a very high quality battery and you would be surprised what we can do with a little Wisper magic and a trickle charger! We may have to change the BMS so there may be a charge, however we would let you know what that would be before we did any work. The down side would be the cost of sending the battery to us in Sevenoaks. The upside a good functioning battery for a small investment.

Please PM me or email me at david@wisperbikes.com if you would like us to give it a try.

All the best, David

 

[Peter.Bridge]

Hi David, thanks for your reply, I have tried agin this morning having only travelled less that 1mile and the battery gave up! put it on charge, the light on the charger is showing green when initially plugged in and remains on green but the battery indicator on the battery shows red and only one green. I am assuming the battery didnt survive the last hibernation cycle and has probably reached its last gasp. I will email claud about it today, I know you have been busy and did email you last year without reply but thnaks for your support and those of the forum guys

Hi Al,
We've just bought a 705 with 575 battery with very similar symptoms - what was the outcome in your case ?
Pete

 

[soundwave]

if you only just got it then it will be replaced under warranty just email them tomoz

 

[saneagle]

Hi Guys I hope you are all keeping safe. this refers to a wisper 575 w battery app 4 years old. It has not been overworked and has been well looked after over the years. I put the battery to sleep(Samsung celled with hibernation mode)in January 2020 and decide over the weekend to start to use my bike on a very limited ride( I am 70 and not fit) I checked the battery before fitting:
all lights green and when connected to the charger it also showed fully charged status. Fitted to the bike and then it only showed 3/4 full and when I ran the motor a while(no load) it showed a drain on the display. Took it of again checked the battery(all green lights) connected to the charger all green. I have measured the voltage at 38v from the battery but I am struggling to find an answer. Any pointers would be helpful or is the battery by age finished? I have always ensured it remain fully charged since having it. I know batteries do deteriorate over time and loose capacity but would of thought this would show on the battery display itself.

You need to check it with a voltmeter as soon as you take it off the charger. If it's significantly below 42v (more than 1V), then it's out of balance. you might be able to fix it by leaving it on the charger for 24 hours or more, depending on whether it starts recovering. If it's around 42v, then starts to fall by itself down to 38v, it's knackered. time for a new one. Do that voltage test and report back if you're not sure because there are some other possibilities.

 

[Peter.Bridge]

You need to check it with a voltmeter as soon as you take it off the charger. If it's significantly below 42v (more than 1V), then it's out of balance. you might be able to fix it by leaving it on the charger for 24 hours or more, depending on whether it starts recovering. If it's around 42v, then starts to fall by itself down to 38v, it's knackered. time for a new one. Do that voltage test and report back if you're not sure because there are some other possibilities.

Hi all, so my story - also posted in wisper clinic

I bought a 3.5 year old wisper 705 with the 575 battery for my wife off Facebook marketplace. When it arrived we did a quick round the block - all seemed ok. My wife cycled to the farm to get some eggs but on the way back the display went off and the assist went off. We tried charging until the charger light went green (which took 20 mins) and tried again but the same happened (worked for mile then went off). When I pressed the battery check light immediately after the display and assist went off it was just on red, but after a few minutes if I try again it shows 2 green lights out of 3.

I charged it again and checked with a voltmeter straight after charging - 38.3 V. I checked it again it a few hours later and it was the same

As saneagle suggested, I have put it on the charger again and will leave it 24 hours, seems to be charging for longer (red charging light on charger for more than an hour so far) and check the battery afterwards.
One thing I was concerned about was if the battery is switched off and removed from the bike, if I press the battery check, nothing shows (as you would expect)
If I put the battery into the bike and click it in (with it switched off) and press the battery check it shows 1 red light. I was wondering if that was normal

Thanks
Pete

 

[Peter.Bridge]

....
As saneagle suggested, I have put it on the charger again and will leave it 24 hours, seems to be charging for longer (red charging light on charger for more than an hour so far) and check the battery afterwards.
One thing I was concerned about was if the battery is switched off and removed from the bike, if I press the battery check, nothing shows (as you would expect)
If I put the battery into the bike and click it in (with it switched off) and press the battery check it shows 1 red light. I was wondering if that was normal
..

OK - the charger light turned green indicating the battery was full and I checked the voltage :41.1v - that seems more hopeful. I've put it back on the charger and I''l leave it on for 24 hours (even though the charger light is green) and report back

 

[saneagle]

OK - the charger light turned green indicating the battery was full and I checked the voltage :41.1v - that seems more hopeful. I've put it back on the charger and I''l leave it on for 24 hours (even though the charger light is green) and report back

You need to try it in the bike too to see if it's better now. if it is, another few hours charging should get it to 42v.

From what you've described, there might be other problems, but you need to deal with one at a time.

 

[Nealh]

One suspects balance is out, personally I would try using it and see if balance pans out a bit better ove rthe next 2 or 3 charge cycles. I think nowadays there is little merit in leaving on a 24hr charge as they should be montiored and tbh goes against most recommendations we make today regarding charge safety.

 

[Peter.Bridge]

Ok thanks everyone, tried using it yesterday - 5 miles until it cut out. Put it on charge, only charged for 20 minutes and ended up less than 40v - tried again this morning - it is gradually getting worse. Spoke to Adrian at Wisper, he confirmed I need a new battery - was worth a try !

 

[Wisper Bikes]

Hi Peter, I tend to agree with Adrian unfortunately, if the previous owner had left the battery flat for an extended period of time this could have damaged the cells.

All the best, David

 

[isla]

Hi Al, never say die!

If you would like to send it back to us, we will see if we can revive it. It's a very high quality battery and you would be surprised what we can do with a little Wisper magic and a trickle charger! We may have to change the BMS so there may be a charge, however we would let you know what that would be before we did any work. The down side would be the cost of sending the battery to us in Sevenoaks. The upside a good functioning battery for a small investment.

Please PM me or email me at david@wisperbikes.com if you would like us to give it a try.

All the best, David

Interesting that I have the exact same problem after putting my battery into hibernation and lights showing the same but when I rang Wisper yesterday I wasn't given any info about sending it to be reset. Told to either buy a new battery or sell the bike if I didn't use it regularly.

 

[Wisper Bikes]

Interesting that I have the exact same problem after putting my battery into hibernation and lights showing the same but when I rang Wisper yesterday I wasn't given any info about sending it to be reset. Told to either buy a new battery or sell the bike if I didn't use it regularly.

Who did you speak to Isla?

All the best, David

 

[isla]

Who did you speak to Isla?

All the best, David

Hi David , I’m not sure as I got passed from one to another that had more knowledge about batteries, sounded a bit foreign. BTW the battery is 4 yrs old. Hardly been used, I thought it was in hibernation. I’m actually questioning myself if the last time I charged it , it actually charged. I didn’t pay attention to see if charger light started off red or not so can’t honestly say for sure how long the battery has been like this. Maybe a lesson learned. The other 2 e-bikes we have were all charged at same time and they are still fine. Perhaps the insides of the others are branded batteries so perform better though I know that’s not always the case so who knows. Just disappointed that a bike that cost nearly £1800 is now useless. :-(.