Panasonic Battery Issues

[flecc]

Reference the current price of the battery at £395 which has made some unhappy, I've just learnt the current price in Germany is £535 equivalent, £140 more.
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[tillson]

Reference the current price of the battery at £395 which has made some unhappy, I've just learnt the current price in Germany is £535 equivalent, £140 more.
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Are these batteries actually worth £395 or even £535? After all, they are essentially a small box of chemicals. I know that you could argue that everything is made up of base elements and that a manufacturer adds value by applying a process and producing a useful commodity. Allowing for the research & development costs, of which a portion is spread across other applications and not just ebikes, are the manufacturers fleecing us? I’m not casting aspersions on the retailers, from remarks made on here I understand that they are selling the batteries with quite tight margins. It is just that I am looking at my little battery box and thinking is there really £535 worth of, “stuff” inside it. I don’t know, maybe there is, but a little notion is dancing away at the back of my mind that maybe there isn’t.

 

[flecc]

For a while some subsidised the batteries in the interest of better sales, notably Wisper with a big subsidy on their 14 Ah battery at £295 and to a degree 50cycles with the Panasonic battery dropped to the same price. There is still subsidy there as that German price shows, and those higher prices are true right across Europe.

At the other end the prices are probably partly due to the losses made on lithium batteries due to past high failure rates and partly to the high costs of the very intense research that's been going on in this area. The fact that the batteries are constantly changing, each going through many generations of change as they improve, alone adds considerably to manufacturing costs.

And then there's the huge change in the exchange rates as the value of the pound has collapsed, making Far Eastern profits disappear and their prices jump in addition when they try to sell here at anything like the old prices.

I don't believe that at this time when facing a worldwide recession and Chinese sales are suffering severely, their manufacturers are choosing to inflate prices unreasonably, That makes no business sense.
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[essexman]

Most of the way through the winter my battery was showing 4 lights when i did a test. (i'd take my battery inside each night to charge and i'd test it before i leave).

Recently injury forced me off the bike for ~ 1 month. Prior to restarting i recharged my battery and found that a batttery test gave me 5 lights again!

I wonder if it was something to do with the cold. Maybe bringing the battery inside overnight when the heating is off wasnt sufficient to warm the battery but when it was left inside for amonth it warmed through?

The only caveat to that is that battery performance seems worse even though capacity has increased! (its still cold though) hmmm. I'm going to monitor it for a few months and see if it has improved after a pertiod of warmish weather.

 

[tillson]

Most of the way through the winter my battery was showing 4 lights when i did a test. (i'd take my battery inside each night to charge and i'd test it before i leave).

Recently injury forced me off the bike for ~ 1 month. Prior to restarting i recharged my battery and found that a batttery test gave me 5 lights again!

I wonder if it was something to do with the cold. Maybe bringing the battery inside overnight when the heating is off wasnt sufficient to warm the battery but when it was left inside for amonth it warmed through?

The only caveat to that is that battery performance seems worse even though capacity has increased! (its still cold though) hmmm. I'm going to monitor it for a few months and see if it has improved after a pertiod of warmish weather.

I'm not sure what you mean when you say the battery performance is even worse. Are you going by the charge level lights on the handle bars? If so, I wouldn't place too much faith in them. I thought that my battery was on the way out, but I have found that the actual range of the bike has not decreased.

Try riding it until the battery cuts out and see how far you travel. You will also probably find that the indicator lights will be more accurate for after that as well.

 

[flecc]

Recently injury forced me off the bike for ~ 1 month. Prior to restarting i recharged my battery and found that a batttery test gave me 5 lights again!

When they are not used for a while, these Panasonic batteries uniquely go into a "sleep" mode, suspending chemical activity to retain maximum life.

Fully charging straight from that sleep mode is the same as an initial conditioning cycle so that would re-register the meter and maximise the available capacity.
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[lectureral]

I have now flattened my battery (over several days but I don't think that is significant). The lights changed at approx 5,10,15 miles and I was legs only at 21 miles. All of this was on high power, dawdling along (which ironically uses more battery power, I guess, because I am in the power band more of the time) and with an 11 kg passenger behind me.

The range seems on the low side but perhaps those with a fuller knowledge might care to comment on these data.

Oddly enough, when I did a capacity test on the empty battery I got 5 lights (was 3). I will try the test again when the battery is fully charged.

 

[tillson]

I have now flattened my battery (over several days but I don't think that is significant). The lights changed at approx 5,10,15 miles and I was legs only at 21 miles. All of this was on high power, dawdling along (which ironically uses more battery power, I guess, because I am in the power band more of the time) and with an 11 kg passenger behind me.

The range seems on the low side but perhaps those with a fuller knowledge might care to comment on these data.

Oddly enough, when I did a capacity test on the empty battery I got 5 lights (was 3). I will try the test again when the battery is fully charged.

It is hard to say if 21 miles is acceptable because there are so many other factors to take into account such as temperature, rear sprocket size, terrain and all up weight to name but a few.

I cycle a very hilly route and weigh in at 90 Kg. On a standard 23 tooth rear sprocket, standard power mode and temp > +5 with very little headwind, I will achieve 36 to 40 miles range before the battery cuts out. I have recently gone back to an 18 tooth rear sprocket and this has dropped the range to 28 - 30 miles under the same conditions.

I am also starting to use low power mode and can achieve around 50 miles if I work very hard. (Again under the same conditions as above)

Hope this helps you to gauge the performance of your battery.

 

[lectureral]

Thanks - I should have said that I am standard in the sprocket department and the hills are pretty mild around these parts.

My thinking is that if I took away the passenger, used standard power and upped the speed a bit then I would probably be getting at least 30+ miles, which seems OK.

 

[flecc]

Thanks - I should have said that I am standard in the sprocket department and the hills are pretty mild around these parts.

My thinking is that if I took away the passenger, used standard power and upped the speed a bit then I would probably be getting at least 30+ miles, which seems OK.

I'm sure that's right. A to B found range on full power only was 26 miles (not very hilly in their area) and I found roughly the same. Allowing for you having an 11 kilo passenger and taking it easy so spending more time in the higher range of powers, I think 21 miles is reasonable, and I'm sure you'd easily exceed 30 miles with standard power setting and cycling at a slightly higher pace.
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[Fecn]

The lights changed at approx 5,10,15 miles and I was legs only at 21 miles. All of this was on high power, dawdling along (which ironically uses more battery power, I guess, because I am in the power band more of the time) and with an 11 kg passenger behind me.

The range seems on the low side but perhaps those with a fuller knowledge might care to comment on these data.

That distance seems about right to me... I often have an 11kg passenger behind me and do quite a bit of dawdling... 20ish miles is about what I get and I am 100% sure my battery is giving it's best as it's only been charged 5 times so far.

 

[lectureral]

Thanks Fecn - that is helpful.

The battery is now fully charged - it took 5 hr 30 min which I figure is about right (I always reckoned about 1 hour for each light and 1 hour for them all to go off).

Most importantly - the hare which set me off - the capacity test shows 5 lights.

So I think that our previous hypothesis was right - the capacity test is rendered inaccurate over time and it is worth doing a complete run down of the battery to see if that resets it.

 

[tillson]

My battery has dropped to four lights on the capacity test for the second time. I have just been out and cycled until it cut out and it is back to 5 lights again. I have a route, which I use as a, “control route” for want of a better phrase. Cycling this route again has confirmed that there has been no deterioration in range, which is the most important factor and I suppose it also indicates that the battery is still in good condition.

The only pattern that I have noticed to the charge level indicator lights slipping out of calibration is after I have not used the bike for a few days. Very occasionally after a period of 14 days of continual commuting use, I have a period of 8 – 10 days when the bike isn’t used. When I use it again after the break, I notice that the first charge level indicator light goes out much earlier on my “control route”. This then almost becomes exponential with the first light going out earlier and earlier. The complete discharge cycle seems to re-set the meter and then everything works as expected.

Anyway, the main thing is that the battery seems to be remaining in good condition with no perceivable deterioration in overall range. It’s just the calibration issue that seems to be a bit strange.

 

[lectureral]

Mine has dropped back down to 4 lights again - about a week after going up to 5 when I flattened the battery - I have used it every day since - still above the 3 lights I had before running to empty though.

 

[tillson]

Mine has dropped back down to 4 lights again - about a week after going up to 5 when I flattened the battery - I have used it every day since - still above the 3 lights I had before running to empty though.

Have you experienced any reduction in range when you run the battery down to the cut-off point? The fuil charge to empty range has been quite consistent with my battery.

 

[lectureral]

The short answe is that I don't know. My cycle computer came after I had completed the first conditioning of the battery. The only other time I have run to flat was last week. In addition. I now have my passenger (added weight and I ride more slowly) whereas at the begiining I was on my own.

It is good to know that you have found the range consistent though.

 

[paultrafalgar]

Power consumption versus weight and total ascent

Having bought a Kalkhoff Pro Connect on the 1st March, I read this thread (all 14 pages) with great interest. I attach a small spreadsheet of my rides intended to gauge power consumption. The results made me wonder if the battery capacity was deteriorating. One thing that occurs to me is that, in your discussion, you leave out the weight of the rider and the Total Ascent during the trip. You will see from the spreadsheet that I have tried, in the last column to get a crude measure of the efficiency by calculating the WattHrsPerMile divided by the Total Ascent. For comparison with others I think I might have made that WattHrsPerMile divided by the product of my weight and the TotalAscent (ft-lbs lift). I measured the WattHrs figure by putting a Watt meter in the line when I recharged the battery. This gives a believable measure of power consumption.

 

[paultrafalgar]

BikeTrips On my Kalkhoff Pro Connect

Here's a later version (part of a bigger spreadsheet). Sorry, the column headings are chopped off, the columns are:
Date
Points(in Fugawi)
Miles
Ridden(vsPlanned)
TotalAscent(ft)
WattHrs
WattHrs/mile
WattHrs/mile/ft(of ascent)
There is a graph of the last column at the end. Can anyone explain why the two shorter trips use much more power per mile-ft? I now think that the graph shows no great deterioration in the battery.

 

[JamesC]

Here's a later version (part of a bigger spreadsheet). Sorry, the column headings are chopped off, the columns are:
Date
Points(in Fugawi)
Miles
Ridden(vsPlanned)
TotalAscent(ft)
WattHrs
WattHrs/mile
WattHrs/mile/ft(of ascent)
There is a graph of the last column at the end. Can anyone explain why the two shorter trips use much more power per mile-ft? I now think that the graph shows no great deterioration in the battery.

Like you, I keep a note of charger input vs distance travelled.

Short distances using more energy:
1. Do you charge the battery just before you ride or immediately after you ride ?
If it is your habit to charge after a ride, and there is a gap of a few days before a short ride, then the storage losses could create a significant difference.

2. Probably too obvious, but I am always surprised by the power consumption of the charger when charging is complete and all lights are off on the battery.
Is there any chance that the charger is not turned off immediately on completion of the charge when the charge time is brief after a short ride ?

James

 

[paultrafalgar]

Like you, I keep a note of charger input vs distance travelled.

Short distances using more energy:
1. Do you charge the battery just before you ride or immediately after you ride ?
If it is your habit to charge after a ride, and there is a gap of a few days before a short ride, then the storage losses could create a significant difference.

2. Probably too obvious, but I am always surprised by the power consumption of the charger when charging is complete and all lights are off on the battery.
Is there any chance that the charger is not turned off immediately on completion of the charge when the charge time is brief after a short ride ?

James

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