Supplying chargers is extreme, just supply power points, if someone if wanting to recharge out on a ride, they are likely to bring their own charger anyhow.
I think it was a mistake knocking them back, as mentioned it costs pennies to charge up a bike, so if they are going to be buying food and drink while they do charge, well… you are missing out on that custom for no reason.
tbh it’s bad business sense to knock them back, imo. (unless you are stowed and they are holding up more lucrative customers.)
I’d don’t blame them for walking away, they want to charge their bike, they’ll get it done elsewhere, and you probably just lost out on any repeat business too..
Long as they are spending, I don’t think there should be a problem, if you must charge, a quid or 2 per bike seems fair. Fiver if you want to rip the piss.
Stipulate it’s only batteries allowed inside.