Hi Bob

 

This is what I meant by mountain bikes and the cap where me pump goes went missing young kids down bargain booze i think on the estate up the road.

 

Sounded like a funny a story that you sent a bike back.

 

 

 

thx

 

Bob

Hi wotwozere

I thought it was quite clear from my post that I WOULD NOT attempt to ride the agattu along rough tracks and if I do use them I walk and push!!.Which was why I was enquiring about a throttle I had seen mentioned somewhere which operates only at walking pace.As for returning the bike I think the reasons were also made clear in my post.

styx

Definately buy that lottery ticket!

 

Hi,

I'm pleased that 50 Cycles have got you sorted and hope that you will have good success with the new battery. I think there must be about 6 people on this furum who have returned batteries. Given that stated failure rate, you are a have odds a little under 28000 to 1 to get 2 duds in a row if my school maths serves me correctly. I should buy a lottery ticket this weekend.

 

I don't think your maths is that far our, BM. I heard that 1500 Kalkhoffs had been sold, and if there are only 6 defective batteries out of that lot, there could only be 5 chances in 15,000 of Tillson getting a failure the second time round (as he'd already had one of them), which gives chance in 75,000.

 

That means that if 50 Cycles keep trading at this rate you would not expect another customer to get two dud batteries until the year 2059. Tillson, if you get a third dud then you would have grounds for believing that you have been chosen for greater things, as there is only 1 chance in 2.8 million of that happening, given there are only six duds, and other 50 Cycles customers could rest assured that you had used up the bad luck as you would not expect it to occur again for 18,750 years. That's assuming there have just been the 6 duds, that is...!

But if the duds were sent out again as replacements, the maths would go haywire.

 

Stranger things have happened.

.

It would be interesting to know if the serial numbers of the faulty batteries are concecutive or random.

If they are consecutive the people with the numbers next to the faulty ones could keep a close check on their batteries and the others probably need not worry so much.

If they are random single batteries then the odds have been posted by others ?? - Allan

But if the duds were sent out again as replacements, the maths would go haywire.

 

Stranger things have happened.

.

Not an uncommon thing in computer retailing, won't believe there is a fault until it's returned 3 times.

Not an uncommon thing in computer retailing, won't believe there is a fault until it's returned 3 times.

 

Straight back into stock is common too in computer and electronics components, eventually the dud can go to someone who can't be bothered to return it, so the policy can pay.

.

It would be interesting to know if the serial numbers of the faulty batteries are consecutive or random.

If they are consecutive the people with the numbers next to the faulty ones could keep a close check on their batteries and the others probably need not worry so much.

If they are random single batteries then the odds have been posted by others ?? - Allan

 

There is a manufacturing batch code on the battery. My two faulty batteries were from different batches, so the long odds apply.

 

Hi,

Given that stated failure rate, you are a have odds a little under 28000 to 1 to get 2 duds in a row if my school maths serves me correctly. I should buy a lottery ticket this weekend.

 

I did buy a lottery ticket last Saturday as you suggested and this was the first one for many years.

 

I lost. Is this a good or a bad thing?

 

ps You owe me a quid for giving me bad advice

Just playing around with statistics a bit more (and assuming of course that the seller was not the sort of company which would return the duds to stock!) if a company sold 1500 batteries in a year, I make it that you would expect to see one customer getting a dud first time followed by a dud replacement (ie Tillson's experience), once a year if 39 out of the 1500 were found by customers to be duds. That would be a dud rate of 2.6%.

 

To be honest, that's probably not too bad a failure rate, and shouldn't, in itself, put people off buying a Kalkhoff. But if Tillson get's a third dud, or more examples emerge of people getting two duds, the failure rate would climb.

Just playing around with statistics a bit more (and assuming of course that the seller was not the sort of company which would return the duds to stock!) if a company sold 1500 batteries in a year, I make it that you would expect to see one customer getting a dud first time followed by a dud replacement (ie Tillson's experience), once a year if 39 out of the 1500 were found by customers to be duds. That would be a dud rate of 2.6%.

 

50C have returned the failed batteries to Panasonic for more in depth testing and have promised to let me know the outcome, so I don't think there is any likelyhood of them finding their way back into the system. I will be very interested to know what has been discovered by Panasonic.

 

Also, the guarantee is given by Panasonic, so I don't think there would be much in incentive for a supplyer to feed duds back into the supply chain. That would only increase the number of reported failures, which wouldn't do them much good.

 

My first battery worked perfectly throughout the summer and it was only when the cold weather arrived that it started to develop problems. The second battery only lasted four weeks and was used daily, quite often in sub-zero temperatures.

 

Just speculating on the above, will it stress a battery more (to the point where it could cause damage) to deliver X Amps at say -3 deg. C than at +15 deg .C for example? I’m just thinking that I have some pretty long steep climbs on my route to work and the motor will be drawing a higher current for longish periods in very cold conditions.

 

On my return home, I charge the battery in a heated garage (+15) and give it 5 hours to acclimatise before turning on the charger (5 hours on a timer which is a long enough charge to put all the lights out on the battery). I then leave it for two hours before using the battery. Has anyone thoughts on this charging regime? Is it good / bad / doesn’t really matter? I am looking for anything that may have exacerbated my battery difficulties.

 

Also, the guarantee is given by Panasonic, so I don't think there would be much in incentive for a supplyer to feed duds back into the supply chain. That would only increase the number of reported failures, which wouldn't do them much good.

 

I didn't suspect it with this make since both Kalkhoff and Panasonic would very much want to know about any failures.

 

Just speculating on the above, will it stress a battery more (to the point where it could cause damage) to deliver X Amps at say -3 deg. C than at +15 deg .C for example? I’m just thinking that I have some pretty long steep climbs on my route to work and the motor will be drawing a higher current for longish periods in very cold conditions.

 

No, it wouldn't stress it more, the cold just limiting the amount of current producing chemical reaction reducing the available power, so the stress level would be the same or possibly lower.

 

 

On my return home, I charge the battery in a heated garage (+15) and give it 5 hours to acclimatise before turning on the charger (5 hours on a timer which is a long enough charge to put all the lights out on the battery). I then leave it for two hours before using the battery. Has anyone thoughts on this charging regime? Is it good / bad / doesn’t really matter? I am looking for anything that may have exacerbated my battery difficulties.

 

Certainly that's not bad, and allowing the battery to warm up from a very low temperature before charging is good practice to attain a full charge. However, you don't need to wait to use it after charging, and it could be minutely beneficial to use it immediately, though the gain isn't worth you planning to do that.

.

Edited January 12, 200917 yr by flecc

Just playing around with statistics a bit more (and assuming of course that the seller was not the sort of company which would return the duds to stock!) if a company sold 1500 batteries in a year, I make it that you would expect to see one customer getting a dud first time followed by a dud replacement (ie Tillson's experience), once a year if 39 out of the 1500 were found by customers to be duds. That would be a dud rate of 2.6%.

 

To be honest, that's probably not too bad a failure rate, and shouldn't, in itself, put people off buying a Kalkhoff. But if Tillson get's a third dud, or more examples emerge of people getting two duds, the failure rate would climb.

It was statistical thinking like this that got some of the questionable cot death convictions, originally the doctors said that the chances of two siblings dying from cot death were so far out that it had to be murder, Lightning doesn't strike the same place twice and all that.

Later on good reasons were found that cot deaths are far more likely to happen in a household where it has happened before, the convictions were overturned.

What I'm trying to say is that we don't know why the batteries failed but once he has one fail then he is much more likely to experience a second failure. For all we know the battery could have been kept next to an ultrasound device which changed the insides, or a microwave oven that leaked microwaves. All very small chances but still important when considering freak statistics.

For all we know the battery could have been kept next to an ultrasound device which changed the insides, or a microwave oven that leaked microwaves. All very small chances but still important when considering freak statistics.

 

Although these are very unlikely, there are some other greater possibilities. The supplied charger might be malfunctioning for example, damaging the battery with too high a charge level before cutout. Another but smaller possibility is the that motor software is discharging the battery to too low a level before cutout, taking the cells below damage level.

 

If Tillson were to have a third battery fail, testing the charger as well initially would be very advisable since that would be a likely cause of the trouble.

.

The supplied charger might be malfunctioning for example, damaging the battery with too high a charge level before cutout.

.

 

This is now looking like a distinct possibility as candidate for the cause of the problem... we think we know what is and we are investigating further.

Edited January 12, 200917 yr by Tim

The supplied charger might be malfunctioning for example, damaging the battery with too high a charge level before cutout.

 

This point had crossed my mind and I took the charger with me to 50C. I mentioned chargers to Lloyd but he said it was unlikely so it stayed in the car.

 

When Lloyd handed over the battery, I'm sure he said that it had been fully charged ready for use. When I put it on my charger back home, all 5 LEDs illuminated and it continued to charge for a further hour before they went out.

 

I'll give them a call and ask for their advice on this one. I assume the cut out circuit is in the charger and not in the battery?

 

I'll give them a call and ask for their advice on this one. I assume the cut out circuit is in the charger and not in the battery?

 

Normally with lithium batteries the cutout is in the battery so overcharging would only occur if the battery electronics (BMS) were faulty.

 

The Panasonic system has an important difference though, instead of two connections, three differing active connections between battery and charger and battery and motor, leading me to suspect that the battery management is shared with the BMS by both the motor and charger electronics, giving potentially ideal conditions in both discharge and charge modes. This would be typical of the sort of sophistication Panasonic brings to e-bikes.

.

Edited January 12, 200917 yr by flecc

It was statistical thinking like this that got some of the questionable cot death convictions, originally the doctors said that the chances of two siblings dying from cot death were so far out that it had to be murder, Lightning doesn't strike the same place twice and all that.

Later on good reasons were found that cot deaths are far more likely to happen in a household where it has happened before, the convictions were overturned.

 

I'm not sure I agree with that!

 

Just because someone once misused statistics with tragic results does not give you grounds to declare the whole science to be in default. There lies the road to dumbing down. Remember many statistical techniques were developed specifically to predict failure rates in manufacturing processes!

 

In this instance the fact that one person getting two failures is improbable means that it's necessary to look for another, more likely cause, be it your suggestion of where the bike is kept, returning duds to stock or, the current favourite - charger problems. However if 50 cycles were saying they were had had about 40 duds, or even 100, then it wouldn't be such a surprise one person had had two, and Lloyd would have been right, on balance of probability, to tell him to leave the charger in the car!

Battery charger fault?

 

Hi everybody.

I spoke with Scott at 50cycles today and he requested me to return the charger with my faulty battery as they thought the fault could be with the charger being incorrectly wired.So far I am on my third set of gears and now a second battery and the bike has only done a little over one hundred miles,it's turning out to be a frustrating experience this electric biking.

Hi everybody.

I spoke with Scott at 50cycles today and he requested me to return the charger with my faulty battery as they thought the fault could be with the charger being incorrectly wired.So far I am on my third set of gears and now a second battery and the bike has only done a little over one hundred miles,it's turning out to be a frustrating experience this electric biking.

 

You have been really unfortunate but I'm sure that 50Cycles will sort it out for you very quickly.

I got my replacement battery from them within days.

I had problems with the charger not working sometimes but I used a different adaptor plug and I think that may have solved the problem.

This is now looking like a distinct possibility as candidate for the cause of the problem... we think we know what is and we are investigating further.

 

Can you keep us posted about the charger issue? As I also had an early failure I wonder if there is a dud batch of chargers causing the battery failures. I cannot claim to have used the Agattu much with the new battery but I don't want to damage it if I have a faulty charger.

I did buy a lottery ticket last Saturday as you suggested and this was the first one for many years.

 

I lost. Is this a good or a bad thing?

 

ps You owe me a quid for giving me bad advice

 

The pound is in the post....

Lloyd from 50C has just contacted me to arrange to swap my charger. It's good to know that they are taking this seriously and investigating this issue.

I got home this evening and put the battery on the charger and plugged it in to the other adaptor plug I mentioned earlier - nothing.

I tried it several times but still not a flicker.

 

I then put the 2 pin plug back in the original adaptor plug and it worked.

 

I never know if it will work, and simply by opening up the adaptor plug and fiddling with the fuse holder and the 2 pin plug will it then work. This is very annoying.

I got home this evening and put the battery on the charger and plugged it in to the other adaptor plug I mentioned earlier - nothing.

I tried it several times but still not a flicker.

 

I then put the 2 pin plug back in the original adaptor plug and it worked.

 

I never know if it will work, and simply by opening up the adaptor plug and fiddling with the fuse holder and the 2 pin plug will it then work. This is very annoying.

 

I couldn't see your previous reference to the other adaptor plug. Why were you using it, was the 50cycles supplied original playing up?

.

Hi

 

Try using the next socket it worked with my Microwave.

 

Thx

 

bob

I couldn't see your previous reference to the other adaptor plug. Why were you using it, was the 50cycles supplied original playing up?

.

 

Yes.

I changed the fuse first time it happened and it worked.

 

The next time it happened was a few weeks later and I opened it up and just moved the fuse and wiggled the 2 pin plug. It worked!

 

The same thing has happened about 8 times in 6 months.

 

This most recent event as I said, I used a different style adaptor plug and it worked.

 

Then the next charge the following day it didn't work. So I opened it up and wiggled everything again and it worked!

 

I' wondering now if it might be a poor connection in the 2 pin plug.