desperately need info on battery wiring

I recently designed a box for use at places where electricity and vehicles are unable to get to. (Boats, beaches with no road access, etc.) However I am concerned with how to hook up the batteries and battery charger. The box is designed to hold two 12's , 4 6 by 9's, two amps, head unit, two batteries, and a battery charger.I know how to wire wire everything but the batteries and battery charger. If you can offer any advice it would be greatly appreciated. But please don't steer me in the wrong direction b/c I just spent $1800.00 that I really did not have and would hate to fry it all due to one simple wiring mistake. Thanks for the help!

what kind of battery charger is this? like.. a car one? if thats what you have... thats gonna require some electricity. If you have a site or some info on that charger, i think i can help you out. 1990 Honda Civic HB:

Clarion DXZ545MP H.U.

2- 6.5" Power Acoustik interiors

Diamond Audio 600.1 amp

Diamond Audio 15" M6MKII

Pyramid PB881X 4 CH. Amp

Not much advice on wiring but I would think you would need a battery isolator and make sure you vent the enclosure as batteries give off gas (depending on the type) and you don't want the box exploding..Also I thought batteries needed to be mounted in a metal enclosure and secured with metal clamps but not sure. Sounds like a heavy box! Good luck, Mike

Thanks to all responses but after further investigation I found out the info I needed. The batteries are car batteries and had to be wired in series and the bettery charger had to be wired the same way, however , I know the battery charger needs electricity, it is in the box wioth a covered plug in wired to it to recharge the batteries at a location where electricity is available after being used for about 10 or so hours.Any way, just wanted to thank you all for the responses. By the way, it is a very heavy box weighing in at 257 lbs.