What battery safety requirements apply when transporting an electric power wheelchair (Elektrorollstuhl) inside the passenger compartment of an accessible coach?

1. The battery acid must be drained out before boarding
2. Batteries must be dry-cell, AGM, or sealed gel type (or certified spill-proof lithium-ion), securely attached to the wheelchair frame, with electrical drive isolator/circuit breaker switched off during transport
3. The battery must be removed from the wheelchair and carried in the underfloor luggage compartment
4. Electric wheelchairs must be towed on a separate open trailer