VEVOR Rechargeable AGM Marine Battery, 12V 40AH, with 400A Discharge Current, Ideal for Mobility Scooters, Electric Wheelchairs, Go-Karts, and e-Bikes

It is recommended to choose a battery with a larger capacity.

Yes

Generally, there is no restriction on series connection.

Based on the product information, it does not explicitly mention whether the battery can be mounted in any position. However, it is described as a heavy-duty rechargeable AGM deep cycle battery suitable for mobility scooters, electric wheelchairs, and other light electric vehicles.

While the product information doesn't explicitly mention compatibility with solar panel charging, its rechargeable design and versatility suggest it could work with appropriate charging equipment. For confirmed compatibility, I would advise consulting the manufacturer or a qualified professional.