We struggled for years with a 2500lb hand winch, almost to the point of not bothering taking the boat out.
Thought about electric winch but one or two at the club got those plastic box types with handles and they were very, very slow so carried on with the hand winch.
Then I saw 3000lb Winchmax on eBay for less than £100 with remotes so ordered one - WOW I wish we had got one years ago. From clipping the hook on to being fully on the trailer - less than a minute!
I got a second hand 45AH car battery to try for £5 which has proved more than capable.
The battery is in a plastic battery box with the relays etc which I keep in the boot. While driving I have a lead which plugs into the aux towing socket to charge the battery.