Absolutely, you should set it to 50 Ah in order to have the SOC and as a result the range estimation working correctly. Even so you may need to adjust the charge level reading regularly as it tends to shift by time. With the Fran BMS you should be good, check the Fran directory on the Google share by Sylvain. I would strongly recommend to disconnect the charger and the BMS ftom the CAN bus when you change the MC firmware.

For the charger you can use the "EVPS LiMn 36s-2.hex" (< 60 Ah) or the "evpsli02last.hex" (< 120 Ah). For the MC I use the matching "MCR2042-4.hex" but the "MC_FRA20B01.hex" should work as well. On the ICM the generic "DIY_1708.hex" should be fine. The BMS firmware will depend on the hardware you have.

Sorry for the delay, I will check tomorrow eventually which firmware set is the right one.

The V2.1 charger is ok for Li-ion, let me check the proper firmware version (there are 60 and 120 Ah versions out there). Matching MC and BMS firmware versions will be needed as well. You must use a Vectrix BMS with the stock charger. The ICM firmware version is less relevant. 

Great, make sure it is V2.1 or V3 for Li-ion.

Once you have the the Vectrix Diag app talking to your bike it is strongly recommended to take a note of the original firmware versions in case you need to roll back. The risky part is the Motor Controller firmware change, absolutely no disruption is allowed during the process. Should the image download fail in the middle there is no easy way to fix the MC (only by low level reprogramming the processor). Never broke for me though.

Sure, you can find some details here : https://visforvoltage.org/forum/14235-problem-dougas-engeneering-firmware. If you drop me (me@mecano.hu) an email I can send you the files. Note, you will need a specific CAN bus adapter as well : https://www.peak-system.com/PCAN-USB.199.0.html?&L=1&no_cache=1&sword_list%5B0%5D=ipeh002021 (the opto isolated one).

Great. Yes you must* have a BMS for Li-ion cells, check the link Sylvain shared, that is the improved version of the original Vectrix design.

The ESD charger is quite old and far from ideal for Lithium. Even so it is kinda possible to use it with the so called Dugas software and firmware, however there is no guearantee it will work nicely with the above BMS mainly due to firmware compatibility issues. A gold charger (aka Runke v2 or v3) would be much better since those are proven to work with the BMS.

* In a nutshell the BMS controls the charger preventing overcharge and takes care of the balancing session as well.

You can apply 110-150 V DC indeed to the battery terminals indeed to check if the bike powers up. You will need to use an incandescent 40-100 W light bulb inline to prevent excessive inrush current that could damage the Motor Controller.

In the majority of the cases it is the battery. The rest of the Vectrix is quite reliable maybe with the exception of the chargers.

We have a reasonable stock of spare parts here in HU. Even so it would be great if you can share that link, should there be a need for some items from Matteo.