The excess baggage charges if you carried a mobility scooter would be astronomical. Or do you imagine they'd carry it foc? I rather doubt it, they'd say bring a chair instead.
Major safety problems with carrying the battery (which is serious Dangerous Goods)) too. This may not be easy to resolve. Electric wheelchairs are a real pita to carry for this reason.
Rent one at destination would be my suggestion but ask the airline first.