Motor- oder Akkuprobleme

[Giatzo]

Hi Patrick, thank you for your detailed response. I saw your videos and in your case you can clearly hear a noise like tac-tac when the wheel is turning. I don't have such problems. I don't see any gasp like yours... the scooter was working perfectly. After that event I used the battery until 7% and the power were reduced. My opinion is that the BMS is not giving the real state of charge, so probably it is miscofigured or broken.

[patba]

Be aware that when resetting the SOC with the key, the SOC is (most probably) simply estimated from the battery voltage. This is rather inaccurate. Therefore I would not care too much about those jumps in SOC after resetting even a recently charged battery. The much better way to reset the SOC is simply by charging to 100%.

Error 0x52C2 means "Motor current exceeded controller rated maximum", or in other words, the motor current (not the battery current) was higher than the controller (not the battery) supports. This cannot come from a battery issue, in my opinion. But it sounds reasonable for me that a hard and sudden recuperation (that might be equivalent to an almost-short curcuit of the motor phases) can induce such currents. See my encoder problem. There might of course also be another issue with the motor or its wiring.

The battery SOC is surveyed by two independent mechanisms, following to my observations. The first controlling instance is the electronic control unit (ECU). It will reduce the power. You will not see an error message, when this is operating, but "warn volt" and "lim volt".
The second controlling instance, which is set less conservative, is the sevcon controller. When this is operating, you get error messages, like:

"0x49C9; Motor in low voltage cutback; Motor control has entered low voltage cutback region."
I got this message once when I was coming to a steep ascent (ca. 10%) with 7% battery and suddenly gave full throttle, after a longer run at 50 km/h in flat area.

0x45C3: „Low Battery Cut; Battery voltage (0x5100,1) is less than Under Voltage limit (0x2C02,2) for longer than the protection delay (0x2C03,0)”
I got this error once when I switched the scooter on again at 2% and immediately gave full throttle.

I think these are cases when the ECU is not fast enough to regulate down the current.

Patrick

[patba]

Den letzten Abschnitt schreibe ich mal auch noch auf deutsch, damit alle mitlesen können, denn das habe ich hier noch gar nicht berichtet.

Ich glaube, dass der Akku von zwei unabhängigen Mechanismen gegen Unterspannung, Debalancing, ... geschützt wird. Die erste, konservativere Kontrollinstanz ist die ECU (plus BMS). Die reduziert einfach die Leistung, man sieht keine Fehlermeldungen, aber "warn Volt" und "lim Volt".
Die zweite, weniger konservative Kontrollinstanz ist der Controller. Der Sevcon spuckt dann Fehlermeldungen aus, wie:

"0x49C9; Motor in low voltage cutback; Motor control has entered low voltage cutback region."
Ich habe diese Meldung mal bekommen, als ich mit ca. 7% Akkustand in einen steilen Anstieg (ca. 10%) reingefahren bin und schlagartig Vollgas gegeben habe. Vorher war ich eine längere Strecke gemütlich im Flachen bei ca. 50 km/h unterwegs.

0x45C3: „Low Battery Cut; Battery voltage (0x5100,1) is less than Under Voltage limit (0x2C02,2) for longer than the protection delay (0x2C03,0)”
Diese Meldung habe ich 1x bekommen, also ich bei 2% Akkustand den Roller nochmal gestartet habe (Zündung aus-an) und aus dem Stand Vollgas gegeben habe.

Das deutet darauf hin, dass der Sevcon erst einschreitet, wenn die ECU nicht schnell genug ist.

Patrick