Yes they can be but give it a chance
to see if the really need to be recharged.
As a magneto generates more power the faster it spins
if it starts easily there OK. If it is hard starting or you
can’t get it started recharging may help.
As generating electricity would be similar too
the recharging possess I suspect that if you can get
them running they will recharge themselves
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.