I tried again without ignition short (orange/purple wires) and had various failures, but one time success and a full boot.
I was able to enter engineering screen. It seems, cells are defective - or is it a BMS module?
Based on the cell voltage and temp data from the eng screen the issue is likely a failed LMU board (part of the BMS) or a damaged trace on one of the circuit boards that provide the BMS cell voltage data.
The min cell voltage of 65535 is a place holder for "value out of range". Each LMU receives cell voltages from 8 battery cells, each cell voltage reading includes all previous cells in the chain. For example if all cell voltages were at 4V the vaults the LMU would receive are: 4,8,12,16,20,24,28,32. It calculates a specific cell voltage by subtracting the previous value (12-8=4=Voltage of cell #3). If the LMU does not receive a value from one cell this throws off the math and results in a value "out of range".
Assuming the OCV value (276V) is accurate then the average cell voltage of the pack is around 3.45V (276/80).
3.2V is the minimum cell voltage needed to charge a battery normally. 2.5V is the minimum safe limit for the cells but below 3.2V the pack would need to be charged manually.
Short answer there is something wrong in the battery that is causing it to report values outside of normal parameters. Until that issue is resolved the bike will continue to throw faults.
Unfortunately as the bikes PSU is working it will keep drawing small amounts of power from the battery. Over time this will discharge the cells to 0V. As you have no way to recharge the battery time is ticking.
I am not sure what HV vehicle repair resources are available in Germany. I know of someone in the Netherlands that is familiar with Energica battery repair.
Depending on the version of PSU installed in the bike it might be possible to unplug the power going to the PSU stopping the parasitic power draw.
Here are the 2 styles of PSU used in the 21.5kWh battery pack. The upper unit is know as a PSU11, the bottom unit is referred to as a TDK600
The PSU is located behind a cover at the front of the pack, it is secured by T20 bolts and sealed by a o-ring.
Due to the high voltage inside the battery pack I can not suggest you remove this cover... But if you choose to ignore that suggestion you will see either a PSU11 or a TDK600.
The PSU11 can be unplugged from the high voltage supply. The TDK600 is hard wired into the bikes HV circuit, the only way to disconnect power is to cut the HV wires or remove the bottom cover from the battery and unbolt the connections.
Ideally your bike is running a PSU11. There is a 3 pin connector referenced in blue that carries HV power to the unit. Please note the area marked in red is part of the HV circuit and should not be touched.
You can use a non conductive tool to depress the latch on the 3 pin connector and disconnect it.
Removing power from the PSU prevents the cells from being discharged further. Allowing you time to have the original issue repaired.
