There are 10 types of people.
Those that understand binary, & those that don't.
Make that 11 types.
Those that understand binary, those that don't, and those who didn't grasp this joke even if they understand binary.
You should use the "half-split method".
Start your disconnection in the centre.
Then you know which half of the run has the fault.
Then go to the middle of that section and test.
Repeat until you find the fault.
University lecturer - "Have you completed your experiments with pendula?"
Student - "Yes, we are now sat on our ba, doing our sa".
Fetching my coat ...
Time to find out what these MCBs control and investigate, I'll bet the damp has got in or the local wildlife has had a nibble.
If not already done, pop off all your outlets and light switches to get any damp or creatures out. Madam's hair-dryer is a useful tool!
Since you can get two MCBs active, check what they control (and record) so you at least have an idea what not to look at.
That's probably the only currently accessible copy of that website in the known universe!
The WaybackMachine is down after a cyber-attack although they say that the data is safe and they will be back "soon".
I bet you have a N-E fault on your shed circuits.
Disconnect all the neutrals from the neutral bar, hopefully it then won't trip. Then put them back one by one until it does.
This kind of fault can be a nightmare to find so don't lose heart.
Of course, if you had an insulation-tester ...
Yes, it's a question of voltage and control. Most EV packs are >300V most domestic solar is 48V.
There are direct solar-EV solutions available but they are relatively new and not inexpensive.
https://enteligent.com/products/enteligent™-tlcev-t1-trusted-charging-presale
At the energy levels involved this is not a DIY job!!
Sounds like you definitely have an issue of an earth-leakage nature 😞
Does it trip with the main breaker in the shed switched off? I'm assuming that this is a 2-pole breaker.