Kalkhoff battery problem

[Spinalot]

As many of you may know I have recently bought a Kalkhoff Agattu C8 Impulse HS from 50Cycles and I conditioned the battery by discharging it three times as described in the manual. Upon doing this when pressing and holding the battery button for five seconds only four of the five led's lit up. Indicating that it only has 80% - 96% capacity left. I rang 50 cycles and Matt sent a replacement battery and I returned the original battery.
The new battery, after going through the same conditioning procedure again has done exactly the same thing. Only four of the five lights light up. This indicates that the battery has lost up to 20% of its charge capacity.
Is this supposed to do this? If it is then I am not happy, I would expect many more charge cycles before losing ANY capacity.
Can anyone reassure me this is supposed to happen or is there a fault with these Impulse batterys?
50Cycles is shut now but I will be on the phone first thing to see what they say.
I have to admit, for a supposed BMW of the eBike world and the amount of money the bike cost, I am getting more than a little frustrated at the problems I seem to be having.

*edit* Sent a support email off to Kalkhoff head office.

 

[Old_Dave]

Is it the battery.. is it the lights

I suppose that 'normally' speaking as the charge of a pack is directly related to cell voltage then measuring the total battery voltage with a seperate volt meter could provide a clue

 

[Spinalot]

I do not own one old dave, and would be reluctant to start poking it with anything.
According to the manual the five lights (when you hold the button for five seconds) indicated the total amount the battery can hold. After 1100 cycles it will be at 20%. It seems very dubious to me that I should lose a light after three discharges and only three charge cycles.

 

[flecc]

Don't forget that the battery will register lower capacity when very cold, so I'm wondering where you are keeping the bike. When the capacity meter on these batteries registers one LED down in cold weather, the advice is not to bother with conditioning again until warmer weather returns when the meter indicates the true capacity at more normal temperatures. All battery chemistries perform poorly at low temperatures.
.

 

[Spinalot]

Don't forget that the battery will register lower capacity when very cold, so I'm wondering where you are keeping the bike. When the capacity meter on these batteries registers one LED down in cold weather, the advice is not to bother with conditioning again until warmer weather returns when the meter indicates the true capacity at more normal temperatures. All battery chemistries perform poorly at low temperatures.

Also, are you definitely fully charging and not stopping the charge as soon as all five LEDs light?

I read the manual very carefully and as this is the second battery I made doubly sure to follow it to the letter. I keep the battery in the house and have fully charged the battery each time. all lights go out when it is fully charged. Obviously I have the battery on the bike when using it and it is cold at the moment. So should I not ride it in the cold? If that is the case then I would be very disappointed.
Will the capacity go back up when it warms up, or is the loss permanent?

 

[nemesis]

Hi, i have had the same problem. I bought the bike last year and after three months of use my battery was charging to 4 lights. They swapped the battery only for the same thing to happen yet again. Apparenty i was the only one this had ever happened to and the battery was duly sent back to Kalkhof in Germany for testing. Their conclusion.... a faulty led light!!! What rubbish, you can test yourself the led lights. Anyway after three battery replacements costing over £700 each, guess what the problems appears to be? A faulty charger !!! This was tested when the bike went back to them for 2 weeks and was deemed to be ok, also a new motor was fitted. Some one who say remain nameless at the store said it was just probably a faulty bulb and live with it!!! So thank goodness it isn't only me and i hope the store in question are reading this.

 

[Spinalot]

Hi, i have had the same problem. I bought the bike last year and after three months of use my battery was charging to 4 lights. They swapped the battery only for the same thing to happen yet again. Apparenty i was the only one this had ever happened to and the battery was duly sent back to Kalkhof in Germany for testing. Their conclusion.... a faulty led light!!! What rubbish, you can test yourself the led lights. Anyway after three battery replacements costing over £700 each, guess what the problems appears to be? A faulty charger !!! This was tested when the bike went back to them for 2 weeks and was deemed to be ok, also a new motor was fitted. Some one who say remain nameless at the store said it was just probably a faulty bulb and live with it!!! So thank goodness it isn't only me and i hope the store in question are reading this.

Wow, well that is interesting. Matt said to me he had never heard of this happening before with my first battery. Lets see what they say tomorrow on the phone.

 

[Spinalot]

Just had a thought regarding a faulty light, This cannot be right as the light would not light up when I have a full charge. It charges to five lights. It is only when you do the "five second hold" capacity test theat I get four lights.

 

[Zebb]

I would think to be honest if there is a fault at all it will be with the charger. When your using these battery's in cold weather you will lose distance.

Mine will lose the first indicator in the winter quite quickly on top power setting and just about do 23 miles when its cold.summer time I can achieve 30 miles on the same route on top power setting.

So all I do is use a lower power setting and can normally get about 26-28 winter.

I do understand the fact that your saying its not showing off the charger but I would expect its the charger if its happening on second battery.

 

[50 Hertz]

This happened to me with my Panasonic battery back in June 2008 and I am happy to say that 13000 miles later, that battery is still performing well.

First of all, when you say that you have conditioned the battery, have you ridden it until the battery is so depleted that the motor cuts out completely, leaving you to ride home unassisted? If not do so however many times the manual states.

My battery still shows 5 LEDs on the capacity test, but occasionally drops to 4. I think this is more to do with drift in the capacity measuring system, which I suspect is crude. To retrieve the 5th LED, when I can be bothered, I ride the bike until the battery is completely depleted again. After a nice lengthy full recharge, the capacity test indicates a full 5 LEDs.

The charge state indicator also seems to go down in a more linear fashion after doing this too.

Although I am referring to the Panasonic system, I suspect that Kalkhoff have copied a lot of the Panasonic battery system with their Impulse, particularly the charge state and capacity measurement circuitry.

As for 50C never having heard of the problem, of course they have. They will be well aware of it and are just giving you a FO tablet.

I don't think you have much to worry about, just ride and enjoy and don't develop battery anxiety, its quality equipment.

 

[Spinalot]

This happened to me with my Panasonic battery back in June 2008 and I am happy to say that 13000 miles later, that battery is still performing well.

First of all, when you say that you have conditioned the battery, have you ridden it until the battery is so depleted that the motor cuts out completely, leaving you to ride home unassisted? If not do so however many times the manual states.

My battery still shows 5 LEDs on the capacity test, but occasionally drops to 4. I think this is more to do with drift in the capacity measuring system, which I suspect is crude. To retrieve the 5th LED, when I can be bothered, I ride the bike until the battery is completely depleted again. After a nice lengthy full recharge, the capacity test indicates a full 5 LEDs.

The charge state indicator also seems to go down in a more linear fashion after doing this too.

Although I am referring to the Panasonic system, I suspect that Kalkhoff have copied a lot of the Panasonic battery system with their Impulse, particularly the charge state and capacity measurement circuitry.

As for 50C never having heard of the problem, of course they have. They will be well aware of it and are just giving you a FO tablet.

I don't think you have much to worry about, just ride and enjoy and don't develop battery anxiety, its quality equipment.

Thanks 50 hertz.

Yes I conditioned the battery as told. Riding it until the motor cut out and the system switched itself off.
The problem is not that it wont charge to full, but that it says the capacity of the battery is lower than new. Holding the button in for 5 seconds shows how much the battery can hold not the state of the charge. Pressing the button and releasing shows how much charge is in the battery. So now the battery has been on the charger and all five lights light up when I press the button. When I press and hold the button only 4 lights light up.
If there was not a problem and it was normal for it to fluctuate why did Matt change it for me my first battery?
I think I am getting a bit of "battery anxiety" as you put it. But only because it is so expensive and I am left wondering just how reliable kalhoff's really are. This bike cost more than my last car did.
Am I being unreasonable expecting the first 20% of my battery capacity to last a long time? I do not want to be a moaning minnie. :-(

 

[50 Hertz]

Thanks 50 hertz.

Yes I conditioned the battery as told. Riding it until the motor cut out and the system switched itself off.
The problem is not that it wont charge to full, but that it says the capacity of the battery is lower than new. Holding the button in for 5 seconds shows how much the battery can hold not the state of the charge. Pressing the button and releasing shows how much charge is in the battery. So now the battery has been on the charger and all five lights light up when I press the button. When I press and hold the button only 4 lights light up.
If there was not a problem and it was normal for it to fluctuate why did Matt change it for me my first battery?
I think I am getting a bit of "battery anxiety" as you put it. But only because it is so expensive and I am left wondering just how reliable kalhoff's really are. This bike cost more than my last car did.
Am I being unreasonable expecting the first 20% of my battery capacity to last a long time? I do not want to be a moaning minnie. :-(

Yes, I know what you mean about pressing and holding the button to test the capacity rather than the charge state, which is a single short press. My Panasonic battery is exactly the same.

50C changed my battery after about a month for the reasons you describe. The new one went exactly the same way after a few weeks. I still have that battery today, nearly 5 years later.

The only real accurate test is to measure range over a set route under the same circumstances on a periodic basis. This will tell you if the battery really is losing capacity.

 

[helecats]

I wonder if someone on this forum could explain what battery conditioning is for. I read somewhere that it was to set the battery level gauge. As far as I have read one of the worst things you can do to a li-ion battery is fully discharge it. I use LIPo's quite a lot in RC helicopters if they are discharged down to 3.3 volts per cell they are damaged, I thought li-ion were similar. I guess the controller must limit the level of discharge voltage to prevent any damage, but I would have thought 3 discharges in a row would be risky?

 

[50 Hertz]

I wonder if someone on this forum could explain what battery conditioning is for. I read somewhere that it was to set the battery level gauge. As far as I have read one of the worst things you can do to a li-ion battery is fully discharge it. I use LIPo's quite a lot in RC helicopters if they are discharged down to 3.3 volts they are damaged, I thought li-ion were similar. I guess the controller must limit the level of discharge voltage to prevent any damage.

flecc! Where are you flecc?

 

[rog_london]

I'm totally puzzled about how those five LEDs can possibly do what is advertised. I don't mean the first short push which gives you the state of charge - I mean the long push which is somehow supposed to indicate the remaining total capacity of the battery.

As far as I know there's only one way to measure the total capacity of a battery - and that's to totally discharge it (as far as cut off) after a full charge while measuring the current and time. You certainly can't do that in five seconds. Two other possibilities spring to mind: (1) wait for a full discharge and then set the lights accordingly, or (2) keep track of the passage of time and also the usage and make an estimate based on those. I suppose there's a third possibility and that's to combine (1) and (2).

Any of these could easily be wide of the mark. Just consider that years could go by with never a full discharge occurring to set a reference point. Consider also that if the battery is kept cold its life will be much longer than if it's kept permanently warm, and also that its capacity will be lower if it's cold than if it's warm. All measurements will be heavily skewed by storage temperature, discharge temperature and average discharge current, which would be very hard to factor in to any calculation.

I'm tempted to think that the 'battery life' indication (long push) is a pretty wild guess at best - and a total fiddle at worst.

Rog.

 

[Scimitar]

The battery health indicator works by drawing a predetermined current through a known resistance for a set period of time. The resultant voltage drop is measured and, given the characteristics of a particular battery chemistry, an indication can be given of the state of charge or battery health. A full discharge isn't required.

 

[Geebee]

Even with mobile phones they suggest you run the battery pretty flat on the first 3 charges to allow the chemistry to work to its best and for longest life.
As long as you don't take it below the safe minimum voltage for your battery chemistry (which the controller will prevent) it should not hurt occasionally but according to most manufacturers it will shorten battery life if done constantly.

My bikes get one good discharge and then I just use them as I need, I have noticed with Lithium batteries in assorted devices that it take about 5 or so charges to get up to max capacity.

 

[daveboy]

I'm totally puzzled about how those five LEDs can possibly do what is advertised. I don't mean the first short push which gives you the state of charge - I mean the long push which is somehow supposed to indicate the remaining total capacity of the battery.

As far as I know there's only one way to measure the total capacity of a battery - and that's to totally discharge it (as far as cut off) after a full charge while measuring the current and time. You certainly can't do that in five seconds. Two other possibilities spring to mind: (1) wait for a full discharge and then set the lights accordingly, or (2) keep track of the passage of time and also the usage and make an estimate based on those. I suppose there's a third possibility and that's to combine (1) and (2).

Any of these could easily be wide of the mark. Just consider that years could go by with never a full discharge occurring to set a reference point. Consider also that if the battery is kept cold its life will be much longer than if it's kept permanently warm, and also that its capacity will be lower if it's cold than if it's warm. All measurements will be heavily skewed by storage temperature, discharge temperature and average discharge current, which would be very hard to factor in to any calculation.

I'm tempted to think that the 'battery life' indication (long push) is a pretty wild guess at best - and a total fiddle at worst.

Rog.

Hi I have two kalkhoff batterys one shows 4 lights on the capacity test and one shows five.The one
that shows 4 lights will do approx 5 miles more on the same run(44 miles) they are both 10 amp and I
weigh 100kg.Also the battery with four lights seems to drop down to one bar on the handlebar lights
pretty quickly but just keeps going,David

 

[Clumphillian]

I did have "battery anxiety" at first, a bit like being a new parent. Now I'm a grandparent, I just trust the his and hers batteries to get on with it and they do....

Sent from my HTC One SV using Tapatalk 2

 

[flecc]

The primary reason why conditioning is essential on the Kalkhoff-BMZ batteries and the Panasonic ones for their crank unit is to set a zero charge point for the meter LED circuit so that it will register correctly subsequently. Over time the meter can drift out again, so if after long use the meter is suspected to be inaccurate, a fresh conditioning cycle can reset it's zero point. Obviously the key thing is to get the battery as near to empty as practical to set the zero content point. However, never discharge them externally with resistors or bulbs, since "empty" on lithium batteries means the minimum safe level, not totally empty which destroys them. Your e-bike's low voltage cut-off acts at the safe low point.

Because batteries under perform in very cold conditions, a conditioning reset is best not done then since it may not be necessary, a low reading just being due to the cold. The battery can still be used in cold conditions though without doing any harm, but it's best to bring it up to room temperature to charge it, since charging when very cold can do some harm and not be productive.

Some battery makers and some other authorities believe that the cell contents need conditioning to bring them up to full performance, but this is hotly disputed by others. However, since a full conditioning cycle does no harm, it's worth doing on all new lithium batteries, whether they use a sophisticated meter or not. I don't believe that multiple conditioning two or three times is necessary, once done properly should be plenty.

Rog. The capacity measuring on these batteries is surprising consistent and definitely not a fiddle in any way. It isn't linear though, each LED step being a different capacity proportion and larger in the middle region, but the measures are consistent as said, despite not being a precise measure of a quantity at each step. I've no idea how that circuit works, my best guess being cell bank internal resistances since those rise with cell age, but work consistently it definitely does.
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