Panasonic Battery Issues

[Fecn]

Re 1.This would affect long trips as much as short ones surely? I do in fact charge immediately on return.
Re.2 ditto i.e. this doesn't explain why short trips use pro-rata 4 times as much power. My suspicion is that there is something wrong with the metric "watt-hours/mile/ft ascent" but I don't understand what

My suspicion is that you are able to put in more pedalling effort once your legs get warmed up after the first mile or two.

Batteries will deliver more Amp-hours the less Amps you use. For example, a 10Ah battery can deliver 1 amp for 10 hours, but may only manage 10amps for 45 mins... or 20 amps for 15 mins. This means that hill climbing where the battery must deliver high currents for long intervals will have a disproportionately draining effect on the battery which won't be accounted for in the hours/mile/ft ascent metric.

As this thread has floated back into view once more, I thought I'd add on my battery charges graph which now contains 31 charges in total since the start of February. My battery is the orange blobs, and my wife's is the blue squares. The X axis is the number of LEDs showing on the battery before it went into the charger (0.5 = flashing, 0=cutoff reached), and the Y axis the the Ah absorbed by the battery (based on a charger efficiency of 85% as per my other post a few pages back).

As you can see, the battery meter on the panasonic batteries is surprisingly accurate. Each light extinguished seems to equate to about 2Ah of charge used up right down to the last LED remaining. I believe the flashing is supposed to indicate 10% or less remaining, but it seems to be more like 15% in practice.

 

[JamesC]

Re 1.This would affect long trips as much as short ones surely? I do in fact charge immediately on return.
Re.2 ditto i.e. this doesn't explain why short trips use pro-rata 4 times as much power. My suspicion is that there is something wrong with the metric "watt-hours/mile/ft ascent" but I don't understand what

Paul
My thinking is as follows:
Suppose that you consume 10 watthrs per mile of battery capacity when you are out cycling.
If you cycle 2 miles, you would need to replace 20 watthrs.
If you cycle 15 miles, you would need to replace 150 watthrs.

If the battery loses some capacity between each outing (let's say 10 watthrs), then there is an extra 10 watthrs required from the charger on both the short and the long ride.

So now we have
2 miles needing 20+10=30 watthrs which is 15 watthrs/mile
15 miles needing 150+10=160 watthrs which is 10.7 watthrs/mile

However, if you charge the battery just before each ride, then nothing is lost, and both journeys would show as 10 watthrs/mile.

James

 

[kodokan]

Hi all

Just to add to the very useful information in this thread..

I've got a 6 months' old Kalkhoff Agattu-clone (the Dover Cycles Raleigh one), and have just done a conditioning cycle on my battery too. Over the quite harsh winter here in Switzerland, I've noticed that the battery's capacity meter has dropped from 5 down to 3 lights (no real idea about the actual ability to hold a charge over a certain distance, as I don't have a regular commute and the charging pattern's a bit ad hoc).

I've just completed a 'drain it dry-charge it up' conditioning cycle, as suggested above, and it's back to 5 lights on the ten second hold test.

For info, the full discharge took about 45km, almost all on full power with some steep hill climbing, a lot of it with heavy shopping in the large panniers, or pulling a child/shopping/recycling-laden trailer, or both! And I've got an 18 tooth sprocket on the gears. I think that's rather a good performance, and it's nice to know the bike's worst possible range for longer rides this summer. I was on a flashing single light for at least the last half of that, though, so it'll be interesting to see if the handlebar metering has improved now.

kodokan

 

[Barry Heaven]

Hold the button down for 10 seconds and it gives you the capacity left in the battery. Should be all 5 bars which is 10Ah. Some of us had had the capacity reduce to 4 bars so 8Ah. This is independent of how much charge is in the battery - it could for example be discharged and flashing but you would still get 5 bars if you held the button down.

Sorry but I'm puzzled now. I held down the button. It immediately showed 5 bars and then went out. After 6 seconds it again showed 5 bars but all lights went out completely at 10 seconds.

Does this test mean I have full capacity?

It should be a fully charged battery but I have also found a drop off in performance which could be due to the cold weather, but now I'm not so certain.

 

[flecc]

That second reading was showing full capacity, assuming you didn't wobble your finger and get a double first reading through the contact breaking and remaking. Try it again if in any doubt.

Very cold weather does severely affect range and performance.
.

 

[Barry Heaven]

That second reading was showing full capacity, assuming you didn't wobble your finger and get a double first reading through the contact breaking and remaking. Try it again if in any doubt.

Very cold weather does severely affect range and performance.
.

Thanks for that reassurance Flecc. I tried it twice, made sure my finger held it down and got 5 bars on the 2nd reading each time.

I've realised that battery performance offers a wealth of opportunities for things to get neurotic about.

 

[flecc]

I've realised that battery performance offers a wealth of opportunities for things to get neurotic about.

It certainly does! Don't worry though, Panasonic's record on lithium batteries has been impressive for over five years now and these latest ones are lasting beyond two years with very little loss of capacity. Would that they were all the same.
.

 

[richardmu]

Panasonic battery on the Wisper 806fe

I'm now beginning to get a bit twitchy after reading all these posts! Is the 806 the only 2009 Wisper with a Panasonic battery?

Very early days, but my new 806 is giving me some concerns about the range.

I have only done one full discharge/recharge cycle and after a 12 mile run today the handlebar indicator lamps show a single green one down from four, and the capacity leds on the battery show a single led indicating 20%. I don't need 40 miles from a charge but 20 would be the minimum.

Anything to worry about in your opinion? Should I do another couple of cycles and then see how it goes?

 

[flecc]

Another cycle, but then try the range without bothering about what the lights are telling you. Handlebar meters are notoriously inaccurate, especially if checked when running under load, and lithium batteries chemically tire under load and then recover energy when the load is eased.

The only true reading is the actual range achieved.

Don't worry about the earlier posts in this thread, most of the alarm was premature and batteries unnecessarily changed. They've been lasting two years so far with very little loss of range or signs of dying.

I can't speak of the range on the 806fe and much depends on the rider input. 40 miles sounds far too much to expect from a folder with a 216 Wh battery though, 20 to 25 miles sounds more like being possible.
.

 

[richardmu]

Thanks flecc. Advice much appreciated.

I will try another full discharge/recharge cycle and then focus on the range.

 

[Wisper Bikes]

I'm now beginning to get a bit twitchy after reading all these posts! Is the 806 the only 2009 Wisper with a Panasonic battery?

Very early days, but my new 806 is giving me some concerns about the range.

I have only done one full discharge/recharge cycle and after a 12 mile run today the handlebar indicator lamps show a single green one down from four, and the capacity leds on the battery show a single led indicating 20%. I don't need 40 miles from a charge but 20 would be the minimum.

Anything to worry about in your opinion? Should I do another couple of cycles and then see how it goes?

Yes the folding bikes are the only ones with Panasonic batteries.

Best regards

David

 

[richardmu]

I got another 8 miles today before it died the death and there was no assistance. That gives a total of about 20 miles.

I have done another full charge as flecc suggested and I'll check the range again. 20 miles is acceptable I suppose. I don't really expect much more from a small batteried folder.

David. If you're looking for someone to test the new 806Alpino please send it along to me and I would happy to oblige. Don't rate your chances of getting it back though if it performs as well as expected!

 

[Wisper Bikes]

Hi Scott, mainly because I specified the use of the Panasonic CGR18650CG 36V 2250mAh cell, and have been to the PortaPower (HK) Ltd (Yiklik) in Shenzhen and seen them being made. You are badly mistaken if you think that Panasonic cells are only used on bikes assembled in Germany. I would hazard a guess that many many more of these cells are used on high end product in China than the rest of the world put together. Please don't labour under the misapprehension that all Chinese product is poor quality, my Apple MacBook Pro, my Olympus E500 camera and of course my Wisper bike are all made there!

FYI we currently have the Panasonic CGR18650DA cells which pack a larger 2450mHa punch under test for our new kit and 1006 models as even though they do not recharge successfully for as many charges as our lithium polymer batteries the power density is higher.

I dont understand your comments regarding "the already well branded type of battery and motor combination'' this set up is unique to Wisper as are all our battery/motor set ups. Which set up do you mean, we have two in use on the 806 series, the Bafang and the Dapush?

Best regards

David

 

[Wisper Bikes]

I got another 8 miles today before it died the death and there was no assistance. That gives a total of about 20 miles.

I have done another full charge as flecc suggested and I'll check the range again. 20 miles is acceptable I suppose. I don't really expect much more from a small batteried folder.

David. If you're looking for someone to test the new 806Alpino please send it along to me and I would happy to oblige. Don't rate your chances of getting it back though if it performs as well as expected!

Hi Richard, you will find the Panasonic cells take a little more conditioning than the Li Po cells in your 905 however when they have reached their optimum performance you will achieve our advertised 22 miles, don't forget the battery is 216Wh much smaller than the 504Wh battery in the 905. Our 806Alpinos utilise the larger 324Wh Panasonic set up and will cover 32 miles on a charge.

I would be delighted to let you borrow one to test, and don't expect to see it back as I know you will fall in love with it. You would need to work on how to justify the expense of having three Wispers in your household though!

All the best

David

 

[Wisper Bikes]

Hi Scott

Wisper 806 batteries utilise Panasonic cells, I have told you which ones, what's the problem? Are you suggesting I am not being honest?

David

 

[Fecn]

Scott,

Panasonic 18650 batteries are commonly available and used in all sorts of things. The 18650 designation describes the cell shape - it means they are 18m diameter, 65mm long - It's a very common cell format and very popular.

For example.. my Dell laptop has 6 of them inside it's battery pack... I have another one which came out of my old TomTom satnav. Panasonic make far more batteries than just the bike packs. I believe that Sony use panasonic cells in their laptop battery packs too.

Saying that Panasonic wouldn't have capacity to supply cells to Wisper is frankly ridiculous. Maybe they'd have a shortage of their Pedelec style batteries made into packs already, but they make the 18650 cells by the millions for use everywhere. The laptop market for 18650 cells is truly vast, and it's these cells which David has said he is using. Incidentially, it's 18650 cells which are used for the Tesla roadster because they mass-produced in such huge quantities that they offer the best price-per-watt... Tesla use nearly seven thousand of the 18650 cells in each of their packs.

To make a 24V pack from 3.6v cells, you use 7 of them in series (which would give 25.2 volts)... then you deduct around 0.7v for the protection circuitry in the BMS. You get a usable voltage of 24.5v.. Round the 0.5 down and you've got 24v.

.. and just to illustrate quite how easy it is to get panasonic 18650 cells (though not the identical model nmumber CGR18650DA) ... Here they are on ebay.. eBay.com.my: Panasonic Li-ion Lithium 18650 3.6V/3.7V 2.9Ah/2900mAh! (item 270414142589 end time Mar 21, 2010 00:16:48 MYT)

 

[Wisper Bikes]

I think you must have misread my earlier post, your answers are there.

I will check on the cell code, I have quoted the cell we are testing on the larger bikes and all 36V models of the 806.

No one is knocking your cells, don't get so defensive!

All the best

David

 

[Wisper Bikes]

Ooops

Scott, I owe you an apology we are not using the Panasonic Cells I quoted earlier in the 24V battery.

We are using the Panasonic CGR-B/T46SE(CGR18650CG) cell.

The ones quoted were specified for tests on the new kit and 1006.

Do you really want a photo? Are you happy to pay for Normans time if indeed I am actually telling the truth, say £50?

All the best

David

 

[Xcytronex]

Scott, I owe you an apology we are not using the Panasonic Cells I quoted earlier in the 24V battery.

We are using the Panasonic CGR-B/T46SE(CGR18650CG) cell.

The ones quoted were specified for tests on the new kit and 1006.

Do you really want a photo? Are you happy to pay for Normans time if indeed I am actually telling the truth, say £50?

All the best

David

Scott
part of the reason Wisper is so successful and eating into your potential sales is down to Davids transparency-honesty and integrity .Try taking note.

 

[Stumpi]

Do you really want a photo? Are you happy to pay for Normans time if indeed I am actually telling the truth, say £50?

Sounds like a fair offer

no charge if you're correct, £50 if you're wrong