Bike battery.
48v 10.4ah = 468 wh
Most vehicles operate on 12v, so,
468 wh / 12v = 39 ah
Allow for inefficiencies
39/.8 is about 50 ah at 12v
A 200w solar panel will deliver about
200w/12v*6h = 100ah at 12v
That maybe optimistic, if is was cloudy.
So lets call it 50 ah at 12v
About what it would take to charge one fully depleted bike battery.
Sorry I just had to double check the math.
So that is about what it would cost to run my fridge/freezer for a day in my imaginary RV.
Since I'd be likely to ride the bike on sunny days. I think a solar powered bike is perfectly reasonable. Especially if you had fancy Lithium Ion batteries in your RV (land or sea based - I guess water based RV could charge bike battery as needed while waiting to get to land
To me a solar powered vehicle seems entirely and easily possible.
As others have said I would not run a 300w inverter from a cigarette lighter socket.
Sorry, I guess they call them power outlets these days.
But we do not know what kind of charger Lectric uses. On average 50 ah / 6 hours is about 8.5 amps at 12V. More than I would pull off the cig lighter, but it may work.