Panasonic motor: sudden lower power

[moomoomoo]

Hello,

I have a Spencer Ivy and I love it: have been using it every day for two years. 17 Ah Battery is good as new and was working very well.

About a week ago the motor suddenly started supplying less power.

It's hard to fathom: the different 1,2,3 settings on the controller still noticeably change the power assistance, it's just that it's lower assistance overall. The torque sensor still works, so that's not the problem, the controller seems fine. The brakes aren't catching and the bike rolls just as smoothly as before.

Anybody have experience of the Panasonic 250W hub motor? Any ideas on what might have caused or be causing the drop in power?

MooMoo

 

[flecc]

That's not a hub motor, they go in the centre of a wheel. Yours is a crank drive unit, sometimes abbreviated as CD.

It's not possible to say from afar what the trouble might be, though it's clearly an internal crank unit or battery one. The fact that it happened so abruptly tends to make the battery much less likely though. One way to eliminate the battery as the cause is to try another one briefly, so try to get to your dealer or Spencer Ivy if you can to try that. Alternatively any owner of a Kalkhoff with the 26 volt Panasonic unit will be using a compatible battery that you could try for a moment. Otherwise, the nature of the fault suggests the unit's shunt might have gone high resistance due to a soldering deficiency.

However, these units are largely unrepairable where electronic faults of this kind are concerned. That's firstly because the circuit board is encapsulated and sealed into the crankcase and also because no spares are available. Repair is by replacement of the unit.

If the fault arose within two years of purchase it's within warranty, and even if just beyond that time, I'd still advise you contact Spencer Ivy to see if they will offer any help, since these units should remain trouble free very much longer than two years.
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[moomoomoo]

Thank you for the reply. Really appreciate it.

I was worried that it might be something about the crank motor, but was hoping that it may have simply been something temporary like a thermal cut-out that could be reset (for example).

I will try another battery. It's given problem-free riding up to now so it's a big shame, and it is a lovely bike.

MooMoo