Small Deep Cycle Should Suffice
Its not going to get much draw down, but it may not be able to be charged on a regular basis either, so if it does get drawn down (no less than 50% of its AmpHr rating), its not going to hurt the battery (car batts don't like to be flattened too many times). For lights, radio, and perhaps a depth or some other electronic, I should think a 100 amp/hr battery should do. Add up the amps to power each appliance times the number of hours of use, double the value so you can cover off a weekend before recharge and thats your battery size. E.g. 4amps total, over a 12 hour period equals 48 AH, so buy a 100 AH battery. Make sense? You have to consider the recharge too. How are you going to keep a charge. Trickle charge on a solar charger through the week? Take it home on Sunday? I'd invest in a 3 stage charger that takes the batt through 3 distinctive charge cycles, too prolong the batts health. Don
