If you can live with some readout inaccuracy, it's best not to bother with conditioning all the time, just use it until you feel you really must reset. This is especially true for winter when the cold weather low temperatures drop battery performance anyway. I'd just use it for the winter and condition the battery for the Spring.

 

N.B. Crossed with Tillson again!

.

thanks, i will do that.....would be a pain to condition the 18a battery if that works in the same way.....

Kalkhoff pointed out that even when the 18Ah battery is down to 60% capacity after 1100 charge cycles, it'll still have more remaining capacity than a new 10Ah battery.

Over what period of time would it to run to 1100 charges ? It could be 10,000 charges but if thats still over 2 years then there isn't much gain. Its the longitivity of the battery thats the crucial factor.

http://www.50cycles.com/images/kalkhoff/batterylife.jpg

ok i will have an 18a one

Kalkhoff pointed out that even when the 18Ah battery is down to 60% capacity after 1100 charge cycles, it'll still have more remaining capacity than a new 10Ah battery.

 

Good point Tim.

 

However, on many lithium battery equipped bikes as I've observed above, the life can be limited not by capacity, but by cutting out due to the increase in internal cell resistance with age dropping voltage below safe levels when under high load.

 

However, I wouldn't expect that to be a problem on the Panasonic unit equipped bikes like the Kalkhoffs since their battery/power management is so good.

.

Is the Wisper 14 Ah battery still more powerful because it is 36V, while the Panasonic are only 24V?

Is the Wisper 14 Ah battery still more powerful because it is 36V, while the Panasonic are only 24V?

 

Yes. But the Panasonic system is more efficient due to the motor driving through the gears. Therefore, the amount of energy consumed by the motor for each mile travelled will be less on the Panasonic bike than on the Wisper.

OK, I am going to argue with this claim of efficiency of crank over hub. The hub is simply a direct drive motor going through three matched cogs to an outer ring. There is little room for loss of efficiency.

 

Now a chain drive of whatever sort is less efficient in the engineering sense by definition - or am I wrong?

 

I think the issue is not perhaps about mechnical efficiency, but about the extent that the Panasonic encourages cyclists to cooperate and cycle when their input is really needed.

 

But here is the rub: I do not think Wh is all it is about. Efficiency of the BMS, the controller ramp, the maximum Amp draw permitterd, all are factors. In fact, I think some 36V10Ah properly designed efficient hub bikes may run as far as a poorly optimised 36V17Ah.

 

Prepare, Bruce, to be flamed:(

 

{crossed with Flecc}

Is the Wisper 14 Ah battery still more powerful because it is 36V, while the Panasonic are only 24V?

 

Just seen your post Bruce, it's actually the reverse. Here's my answer to Eddie.

 

It's capacity that counts Eddie, since the content in power terms is volts x ampere hours. Therefore:

 

The Panasonic 26 volt 10 Ah battery has 260 Watt/hours content fully charged.

 

The new 18 Ah battery at 26 volts has 468 W/h content fully charged.

 

The Wisper battery has 37 x 14 = 518 W/h content fully charged.

 

However, that doesn't mean the Wisper bike and battery will enable a greater range, since hub motors, which by their nature do not drive through changeable gears, spend varying periods operating at much lower efficiencies. Therefore a Panasonic unit equipped bike can get much longer ranges from a smaller number of Watt/hours under many circumstances.

 

Hub motor inefficiency rises in hilly country, the steeper and more frequent the hills, the more the inefficiencies appear. Conversely in flat country the hub motor bike's efficiency can be very high and comparable ranges. The Panasonic system driving though the bike's gears can be running at the optimum motor efficiency all the time, regardless of how much it's slowed by hills.

 

Absolute real life comparisons are impossible though, since the Panasonic system demands certain proportions of rider effort while hub motor bikes don't generally do, especially when throttle controlled.

.

Edited November 2, 201015 yr by flecc

Yes. But the Panasonic system is more efficient due to the motor driving through the gears. Therefore, the amount of energy consumed by the motor for each mile travelled will be less on the Panasonic bike than on the Wisper.

 

Why is it that Panasonic owners seem to get such poor mileage from the 10 Ah battery and I have often seen how users have to be miserly with the Low/medium/ high settings, and even riding unassisted at times to squeeze out extra range.....Obviously the new batteries takes care of this, and why I am after a a Panasonic bike for 2011. But in 2.5 years of having a 14AH wisper I have never had to worry about range, capacity, or using the throttle or not....

 

edit: just seen Fleccs post... as per usual the master of information :-)

Edited November 2, 201015 yr by eddieo

Consider a particular set-up: a 36V 10Ah battery has 360Wh (36 x 10) capacity. At 36V, a 3A delivery to the motor consumes an instantaneous 108W (360 x 3). Assume that, with some pedalling, an average of 108W produces an average speed of 12mph for a given cyclist on a given route. Thus the battery will give up after 3 hours and 20 minutes (360 / 108), or at 12mph some 40 miles (3.33 x 12).

 

If the controller is unnecessarily producing 4A because of inefficiencies in the motor, or because it is over assisting the cyclist, the range drops to 30 miles.

Why is it that Panasonic owners seem to get such poor mileage from the 10 Ah battery and I have often seen how users have to be miserly with the Low/medium/ high settings, and even riding unassisted at times to squeeze out extra range.....Obviously the new batteries takes care of this, and why I am after a a Panasonic bike for 2011. But in 2.5 years of having a 14AH wisper I have never had to worry about range, capacity, or using the throttle or not....

 

edit: just seen Fleccs post... as per usual the master of information :-)

 

And to add Eddie, as it's so cheap and easy to do, very many users have geared up their Panasonic unit bikes to get much higher assist speeds, more than 20 mph sometimes. This will greatly reduce the range since the motor is working much more of the time and working harder at every speed due to more of the speed range being at higher power phase down levels.

 

At 71 years I could get 50 miles from the 10 Ah battery on a standard Agattu but from my eZee hub-motor bikes I couldn't get remotely near that in my area, only 15 miles on my Torq 1, 20 at most.

.

Edited November 2, 201015 yr by flecc

I am still a little baffled by the talk of better efficiency being achieved through the crank motor. The motors themselves are very similar.

 

We have tried both and are at absolute liberty to make the change if we believed that crank drives were more efficient, the truth is we cannot find any real evidence that they are. Indeed when we have put the question to both dealers and customers they without exception have advised to stay where we are.

 

If there was a method of measuring rider input during a journey I imagine we would find that even over a hilly course if we added the power gained from the motor to the power delivered from the rider a hub motor would prove to be slightly more efficient simply because it has a more direct drive to the road surface. Hence Flecc's observation that on a flat road where very little power is needed from the rider both systems have about the same range, I would suggest that in these conditions the hub would be far more effective especially when used in medium power settings.

 

Power settings should also be taken into consideration, on the latest Wisper bikes the maximum power setting is exactly the same as having the throttle wide open. Giving maximum assistance at all times.

 

One reason so many people prefer hub drive is that they need to put less effort into a ride than they would on a gear drive bike, depending on power settings. This benefit obviously costs more in terms of power used.

 

It is not surprising therefore that most gear drive bikes do not have the luxury of a throttle as this on-tap availability of power would reduce the effectiveness of the gear drive system as the benefit of power on demand increased.

 

All said I do understand why some people prefer the way a gear drive works. However when we take into consideration the other advantages of hub drive system including simple servicing, less wear and tear on the gears etc and the added benefit of full throttle operation (whilst we can still use it), we are still convinced hub drive is the way forward.

 

All the best

 

David

 

I am still a little baffled by the talk of better efficiency being achieved through the crank motor. The motors themselves are very similar.

 

The motor similarity isn't the issue David, it's the operating regions as I've explained above.

 

An electric motor of the types used on e-bikes has well understood characteristics.

 

They start from no revs with minimum power, maximum torque and maximum inefficiency.

 

As the revs rise, the power gradually increases and the torque gradually decreases until the the point where they cross as shown when plotted, at around half torque and nearing full power, but the inefficiency remains very high during that period.

 

That point is typically around 8 to 9 mph on a 15.5 mph e-bike, more rarely at extremes of 7 to 10 mph.

 

From that speed point the power rises and the efficiency gradually starts to rise until it reaches it's maximum, typically around 13.5 mph on a 15.5 mph bike, falling fractionally thereafter.

 

It follows that when a hub motor bike is running at around it's optimum power/torque compromise and hill climbing speed of around 8/9 mph, it's at around half revs and inefficiency is high with much more current consumed than when at the maximum efficiency region of around cruising speed on the flat.

 

Since a crank drive motor drives through the gears, falling road speed due to conditions doesn't necessarily mean motor revs drop into the inefficient regions, a lower gear chosen allowing the motor to carry on spinning in the maximum efficiency region at all times.

 

To get emotive e-bike issues out of the picture, there is a valid comparison with cars here.

 

With a car having a very large engine and manual gearbox, one can neglect to change down for a hill and punch up it in a high gear on sheer power alone. This is the hub motor equivalent, power substitutng for efficiency in those circumstances.

 

Try that with a small engine car and it will promptly stall, changing down is absolutely necessary. Doing that enables the smaller engine to do the job less wastefully than the big fixed gear engine.

 

This is not just theory. I know from experience that at my age and fitness I would struggle to get near 50 miles on your 518 Wh battery on a moderate route in my area, more like 40 miles on a good day, but I can reach 50 miles on a 260 Wh Panasonic battery.

 

Even when using power all the time and high power mode freely on hills, on the Panasonic unit I could repeatedly do 35 miles with the 260 Wh battery on the hilliest routes. That's the equivalent of 70 miles on yours which for me is out of the question with the hills round here. In fact some of them I can't climb at all on your bike type, but I can climb any of them with the Panasonic unit, even 1 in 3 with it's far lower peak maximum power.

 

The difference in both range and ability is the efficiency of driving through the gears.

 

All that said, I love hub motor bikes as well and there's much to be said for their simplicity, their more abundant power and the often greater flexibility on how the power is used. And there are many territorial circumstances where the balance of advantages is in their favour.

 

I fully understand that you prefer to use those and have that set of advantages and I respect that valid choice. Long may all customers have such a good choice of systems on high quality e-bikes, try both and choose to suit themselves.

.

Edited November 2, 201015 yr by flecc

Nicely summarised Flecc, nothing to really add other than I think of hub bikes as being stuck in top gear all the time and crank drives of being coupled to a gearbox...also the question of freewheel ability and drag is better on the crank drive systems when compared to the typical Bafang implementation.

as i understand it if the battery say shows 2 lights of charge and then you carry on and hold buutton down for 10 seconds the battery should show 5 light if it doesent show 5 lights i asume something is wrong same as if there are 5 lights of charge 10 second test should show 5 lights

 

jim

Jim

 

The battery must be fully charged before carrying out the capacity test.

All that said, I love hub motor bikes as well and there's much to be said for their simplicity, their more abundant power and the often greater flexibility on how the power is used. And there are many territorial circumstances where the balance of advantages is in their favour.

 

I fully understand that you prefer to use those and have that set of advantages and I respect that valid choice. Long may all customers have such a good choice of systems on high quality e-bikes, try both and choose to suit themselves.

.

 

Thanks for your considered response Tony, it all makes sense.

 

I must say though, I whole heartedly agree with your last two paragraphs. vive la différence!

 

All the best

 

David

Hi David

 

I thought this thread was about Kalkhoff Batteries not Wisper motors

 

Cheers

 

Scott

 

 

You are absolutly right Scott, I will butt out!!

 

All the best

 

David

i dont think test is dependent on charge state if battery is showing 2 light worth of charge i still get 5 lights on 10 second test

 

jim

Nicely summarised Flecc, nothing to really add other than I think of hub bikes as being stuck in top gear all the time and crank drives of being coupled to a gearbox...also the question of freewheel ability and drag is better on the crank drive systems when compared to the typical Bafang implementation.

 

Remember. The electric bicycle with the greatest range is the one where you don't use the assist! So for out-right range, you want the design to positively discourage you from using assist. I think this is what the Panasonic chain drive system with pedal torque sensor does. And that's the real reason for it's increased range.

 

If electric motors really have a small operating range for maximum efficiency then we'd want to gear the motor to the crank cadence because the rider will typically change gear to keep the crank cadence constant. The motor would then be running at effectively constant speed. This argues for a Panasonic-Cyclone layout and the problem is packaging and arranging for low drag freewheels to be in the right places in the system so that the motor and/or the rider can freewheel with as little drag as possible. But back in the real world, electric motors actually have quite a wide speed range where torque and efficiency are pretty much flat. So in reality there's very little need to change the gearing of the motor. Now we're back to friction drives, separate chains or a hub with internal gears. As far as I can tell, there's very little drag from the bearings, freewheel and planetary gears in current Tongxin, Cute or Bafang hubs. So range and efficiency are really about controller strategies. I suspect that a hub motor with a Panasonic torque sensor and controller would be virtually identical in range to the full Panasonic system.

 

If you have a twist grip throttle or full power pedelec, it encourages you to use full throttle. A thumb throttle encourages you a bit less. Perhaps what we actually need is a variable power knob with a cruise control. But then there's still the awkwardness of adjusting the variable power on the fly. Which leads to the torque sensor approach where you don't have to think about it at all. Put more effort in, get more assist. As discussed elsewhere, what I then want is to break the law by making the speed unlimited. If aerodynamics, rolling friction and gradient mean I can pedal at 20, I still want the extra motor power to push that 20 up to 25. I don't want the motor to just cut out and freewheel because it's maximum speed is 20 (or 15).

http://www.50cycles.com/images/kalkhoff/batterylife.jpg

 

Is this going to be backed up with a guarantee to match the fabulous claims? There are one or two, "abouts" in there and mention of 5 or 6 years.

 

With respect, I could produce a graphic showing marvellous ground breaking battery. What actually counts is 1) Does it live up to the claims. 2) Is the manufacturer going to put his money where his graphics are and guarantee the product to perform as advertised. ie 5 year guarantee.

Is this going to be backed up with a guarantee to match the fabulous claims? There are one or two, "abouts" in there and mention of 5 or 6 years.

 

With respect, I could produce a graphic showing marvellous ground breaking battery. What actually counts is 1) Does it live up to the claims. 2) Is the manufacturer going to put his money where his graphics are and guarantee the product to perform as advertised. ie 5 year guarantee.

 

I will be waiting for clarification before I commit on a new bike as well......But my concern is, its a new type of battery? so a bit of unknown? is that correct?

 

a 5 year guarantee would indeed be ground breaking........