Panasonic Error Codes

[Cyclezee]

My sons 3 and a half year old Kalkhoff Agattu died yesterday. My first thought was the battery contact or the battery. The battery contacts are OK and so is the battery.

When the handlebar console is switched on the the 3 power LEDs stay on for about 1 second before going out then the 3 mode LEDs come or for the same amount of time then they go out. This is continuous sequence and I am assuming it is some sort of error code which I have not seen before.

Any ideas or suggestions welcome.

Thanks for looking

 

[flecc]

This sounds as though it's unable to signal all's well at the end of error checking. Although it's obviously communicating with the main unit, it's worth checking and replugging the connector from the handlebar unit under the cowling adjacent to the unit. It's just possible it has one connection not making. Also a couple of hard kicks down on a pedal might help if the internal pedalshaft is binding in some way and signalling pressure on the pedals, since this interrupts the check sequence.

Other than that it's going to be an internal circuit board problem, either internal connection or electronic fault. If you do open it up, this page on my site has the internal connections illustrated and listed half way down, and numbers 1 and 2 in particular, all-internal links for the pedelec sensor and Hall sensors could need replugging

Also worth checking with 50cycles to see if they have any error code information for these units.

 

[Tim]

According to the manual, that means 'No electrical assistance. The torque sensor was unable to reset itself correctly.' Solution 'Restart the system. The system will be calibrated again; during which time no pressure must be exerted on the pedals'.

Here's the latest edition of the manual - error codes are on page 11 I think

 

[Cyclezee]

Thanks to both Tim and Tony,

I will check these suggestions and report back in due course.

 

[Cyclezee]

I checked and cleaned all the external connections without opening the motor casing. The rear terminal and connector was obviously getting hot as you can see from the photos.




The battery terminal connection plate fitted to the bike in the photos is an unused one. The original is shown removed with signs of erosion on the terminals.


So far I have not been able to resolve the problem and guess an internal investigation will be necessary, but that will have to wait until next week when I have some more time.
However, I am guessing there will be no user serviceable parts and it will be a case replacing the circuit board?

 

[flecc]

Unfortunately the circuit board is normally encapsulated in clear plastic and sealed into the crankcase half with it, and the usual method of repair in the past has been a new unit. A number of the older units have been returned to service by using the crankcase half from units with other faults, but of course there aren't any scrap bikes of the newer generation yet to salvage parts from.

There's still the possibility of a repairable internal fault. The internal connections being remade and the pedelec unit and pedal shaft components being disturbed could clear a fault. I favour the pedelec torque assembly and it's plug in connector to the board being likely sources of the problem, and it doesn't take long to reassemble to check if the fault has cleared.

If still unsuccessful and parts are needed, best check with 50cycles in case there has been any change in repair policy. I don't know a UK price but a new replacement unit in France last year was €500.

 

[Cyclezee]

Thank you Tony,

I will investigate further next week when I have some time, but if I can't repair it, the cost of a replacement unit would make it virtually unecomomic to repair.

The Agattu is 3 and a half years old and has done 10,000 miles, so I guess you could say it has paid for itself and could have some value for spares or repair. It originally cost £1175, so it has cost 11.75p per mile, not including electricity, tyres etc.

There is no hurry as I have other bikes my son can use another bike for his commute.

 

[tillson]

I don't know a UK price but a new replacement unit in France last year was €500.

With the Treasure Island Supplement + Rip Off Britain Levy and the, "your knackered without one" factor, that will be about £750 landed in the UK then.

IF it is a faulty power unit, thissituation would make good case for supplying a new unit at factory cost price. Cosigning a bike of this purported quality to the skip at 42 months old isn't acceptable regardless of the warranty period.

 

[flecc]

That's a reasonable cost per mile then, but don't write it off yet. My experience on these units is that more than half of all internal faults can be cleared. That's why I set up my Panasonic support site in the first place, and I've long since lost count of the number of Lafree e-bikes put back on the road after faults in the unit were cleared.

 

[Cyclezee]

That's a reasonable cost per mile then, but don't write it off yet. My experience on these units is that more than half of all internal faults can be cleared. That's why I set up my Panasonic support site in the first place, and I've long since lost count of the number of Lafree e-bikes put back on the road after faults in the unit were cleared.

I understand what you are saying Tony. This evening, I quickly took the motor apart, but could not identify any obvious problems. All the connections are patent, so I'm guessing it could be the circuit board which would not be repairable, so I might just let it go to someone who wants a challenge and is aware of the possible costs involved..........whatever they might be?

 

[flecc]

One thing to check if the motor is still open, the resistance of the torque sensor coils to see if either half is open circuit. It's centre tapped and about 78 Ohms per side. If you stick pins in the three way socket points you can easily check with a meter on that. The coils assembly, indeed the whole pedelec unit, appears the same as the old unit so there may be spares around.

 

[Orraman]

It may be of some interest that in issue 71, May 2009 of A to B magazine there was an illustrated description of how they fitted a sensorless controller to a Panasonic motor.

Granted that was to the older Panasonic motor fitted to Giant Lafree but it might be worth trying if you have access to a sensorless controller. They even offered to send a free pdf wiring diagram for anyone wanting to have a go.

Dave

 

[flecc]

It's the same motor and Hall sensors so that mod would work, but I don't think it's very satisfactory, messy result and losing the Panasonic's best features. The Australian source for the controller they gave dried up immediately so another suitable one would need to be found.

 

[Orraman]

While for me the excellent torque sensing crank is the major feature of the Panasonic motor, would I be correct in thinking that the vast majority of ebikes manage with throttle and perhaps a rudimentary pedal sensor?

Given the quality and free-running capabilities of all Panasonic bikes and my own parsimonious nature I would need to try this fix. I did obtain the pdf from interest and to hold in case of a future catastrophe.

My idea would be to try a small (ESC) controller from a toy aeroplane with a servo tester (microcontroller pulse generator) for the throttle.
This would bring the advantage that the power regulation in the gears and the reduction of power when nearing 15.5 mph could be controlled within fine (my) limits.

Long may it be before I have to put it to the test, at 3 years mine is going strong.

Dave

 

[flecc]

Yes, that should work Dave. I didn't like the A to B conversion which was very messy and ugly. I think it was driven more by an environmental agenda than an aim to achieve a good e-bike solution.

The Panasonic motor isn't very powerful, relying on it's drive through gears and software management to succeed. It's far less powerful than throttle control bikes usually are, another reason why I don't favour this solution.

 

[Cyclezee]

One thing to check if the motor is still open, the resistance of the torque sensor coils to see if either half is open circuit. It's centre tapped and about 78 Ohms per side. If you stick pins in the three way socket points you can easily check with a meter on that. The coils assembly, indeed the whole pedelec unit, appears the same as the old unit so there may be spares around.

Thanks for the advice Tony, but I had already put it back together. I am going to leave it to gather dust for the time being in the hope that one day in the future I will come across a motor going spare and can resurect it. The bike is still in good condition, but of little value without a working motor.

On another unrelated issue, the 10Ah Pansonic battery, which was a replacement about 2 years ago, had droped down to 8Ah or 4 LEDs about 3 months ago, is now back up to 5 LEDs again and has been for about 3 weeks

 

[flecc]

On another unrelated issue, the 10Ah Pansonic battery, which was a replacement about 2 years ago, had droped down to 8Ah or 4 LEDs about 3 months ago, is now back up to 5 LEDs again and has been for about 3 weeks

That's a result of it's sleep mode. After standing idle for a while, to avoid eventual failure the internal BMS disconnects so the small current drain due to that ceases. Lithium cells do not self-discharge but do chemically recover when rested as they are now, so signalling a slight increase in voltage to light the extra LED is to be expected. If put back into service, the apparent gain in capacity would almost certainly quickly disappear again.

 

[Cyclezee]

That's a result of it's sleep mode. After standing idle for a while, to avoid eventual failure the internal BMS disconnects so the small current drain due to that ceases. Lithium cells do not self-discharge but do chemically recover when rested as they are now, so signalling a slight increase in voltage to light the extra LED is to be expected. If put back into service, the apparent gain in capacity would almost certainly quickly disappear again.

I know about the sleep mode Tony, but this battery has been in use everyday until last Thursday and the change was first spotted by my son about 3 weeks before the motor died

 

[flecc]

In that case I can only think the battery had been run quite low at one point, constituting a conditioning cycle reset of the meter zero point.

 

[Cyclezee]

In that case I can only think the battery had been run quite low at one point, constituting a conditioning cycle reset of the meter zero point.

Ah yes, due the lower capacity, I beleive he got home on a couple of occasions with one flashing LED on the handlebar control, so that is probably the reason.