Power up using USB without cameras. Can I power up K2 device on USB without Cameras to do firmware upgrade and change settings?

You can power the K2 by USB, but you need at least connect the front cam. Without the front cam, the K2 will constantly reboot after some seconds, as it tries to fix the missing camera.

Can’t connect, takes several attempts, or It can’t read card, keeps saying card corrupt. It would be nice to be able to unplug the main unit, take it to the house do the upgrade, connect with the Phone app to check it and then put it back on the bike. Oh and the Power supply is killing my battery after 3-4 days for some reason. I raise a question about that too by email.

When doing updates, the sd card needs to be formatted as FAT32. Depending on the firmware currently installed on your K2, it formats the sd card in ExFat, if the card is bigger than 32 GB (which, I guess, your card is). But unfortunately the Bootloader cannot read ExFat, which causes the update to fail.

So to make sure the update process runs without errors, you should format the sd card on your PC in FAT32.

Oh and the Power supply is killing my battery after 3-4 days for some reason.

Does you power supply has a blue led? If not, you got an older version of the power supply, which could drain the battery. If that's the case, you should ask for a replacement.

I think the card was faulty or had died. I've stuck a new card in and it's working more reliable and has now done the update. It was still a pain having to walk up to the garage several times. I'm getting a new power supply too as it looks like I had an early one with a fault.