Need Advice: Temporary Shore Power

[jhlight]

I have a Pearson 30 that is kept on a mooring and used for day sailing. I have a 30 amp alternator on the engine that does a good job keeping the batteries charged throughout the season and I have a 10 amp Black & Decker battery charger I use in the off season to keep the batteries (2 group 24 deep cycle/cranking wet cells) topped off.

I'm planning on taking a weekend trip to another port about an eight hour sail away, so I'll be drawing power for a lot longer than usual. At the other port I'll have access to shore power, but my boat does not have any shore power connections. Since this is something I'll probably only do once a year, I don't want to go through the expense of installing a shore power system on the boat.

At the other harbor I'd like to be able to charge my batteries using shore power, and if possible, also charge the batteries in my laptop from AC. My battery charger is not designed for outdoor or marine use, and the harbor, of course, has a standard 30 amp connector.

Does anyone have an recommendations on how I can charge the batteries off shore power? I'd like to be able to do this safely without having to spend a lot of money.