new 12 ah panasonic battery

[flecc]

How would i know that my battery is less than 80% ? Would it only charge to 4 lights or would it charge to 5 but with reduced performance ?

It's likely to charge to 5 LEDs*, but with reduced range. If the Panasonic type with a capacity check feature, at 80% it will show only 4 LEDs of capacity, despite a 5 LED charge shown.

*This is because the charge meter measures the voltage rise, and this is normally quite high short term at the end of charge, even when the battery is quite old. Eventually even the charge could fail to reach 5 LEDs, but by then you will be well aware of the performance reduction anyway.

N.B. Crossed with Tillson's post.
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[carpetbagger]

On the 10 second test it quite fequently drops to 4 lights but after discharge reset is back at 5. What is the normal frequency by which the battery should drop to 4 ? and why ? It seems i can go for regular rides but then if i leave it a week or so then it drops to 4..

 

[tillson]

On the 10 second test it quite fequently drops to 4 lights but after discharge reset is back at 5. What is the normal frequency by which the battery should drop to 4 ? and why ? It seems i can go for regular rides but then if i leave it a week or so then it drops to 4..

I found that when the battery was new, it dropped to 4 LEDs after about 1 month. I then "re-set" the battery by fully discharging. It then remained at 5 lights for about 6 months before falling to 4. After another re-set, it remained at 5 for about 3 months. It then fell to 4 lights and I didn't bother re- setting it. After another 4 months, the battery became irretrievable from 4 lights and now drops to 3 on occasions.

If your battery is dropping to 4 LEDs after a week or so, then that doesn't sound good. Have you noticed a fall in range.

 

[carpetbagger]

Range seems ok,its just a pain resetting,i thought maybe because i can't ride at regular intervals then maybe its was upsetting the measurement, suppose i better get some rides in before that warranty goes although i still have 12 months left ....This will probably be 4th reset in 12 months

 

[tillson]

Range seems ok,its just a pain resetting,i thought maybe because i can't ride at regular intervals then maybe its was upsetting the measurement, suppose i better get some rides in before that warranty goes although i still have 12 months left ....This will probably be 4th reset in 12 months

If range isn't bothering you, I wouldn't bother continually re-setting the battery. Running it down to cut out doesn't do them any good.

 

[flecc]

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!
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[carpetbagger]

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

 

[Tim]

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.

 

[carpetbagger]

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.

 

[Tim]

 

[carpetbagger]

ok i will have an 18a one

 

[flecc]

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.
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[eddieo]

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

 

[tillson]

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.

 

[brucehawsker]

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}

 

[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.
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[eddieo]

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

 

[brucehawsker]

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.

 

[flecc]

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.
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[Wisper Bikes]

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