Agreed on the wind resistance.
You would suspect a good hill adds to more but in many cases the wind is the greatest enemy.
On my near dead SLA I am lucky to get 18kms on a windy day compared to 25kms I may need to travel, on a normal day its fine.
I had a funny saying.
The wind doesnt go away where hills do.
Meaning once you get the bike going the impact on the batteries is a lot less when KE and GPE has been stored. The wind doesnt aid your ride unless its behind you.
My luck with the weather alot has me facing the wind both ways
It blows one direction in the morning and the other in the afternoon.
I guess where the SLA had an advantage is it could store the KE (kinetic energy). Providing I don't use the brakes stupid like, I can get the power it takes to get the rider and bike going by free-wheeling or the energy stored in GPE (gravitational potential energy) when I climb a hill and go back down.
Weight can work against the wind better than lack of it.
In the end the lighter more aerodynamic bike always wins hands down. But the lesson I learned is to make the most of what you have to carry in your trips.
Brake = loss of energy and the conversion back to electrical energy in regen is a waste unless you really need to use the brakes.