I use solar power on my house.
My house is 5x8 and powered by 12 volt marine battery hooked up to 2 x 15 watts solar panels.. I run several LED lights, car radio, fan and it is a back up for my electronics when their batteries die.
I run most ice season with only 1 battery. 2 when I'm staying over night. I hook up the batteries positive to positive and negative to negative using heavy gauge wire from an auto store. This gives you more capacity and not 24 volts. Your not really looking for more power, just more capacity. Also charges both batteries at the same time, no toggle switch.
I bring the battery home maybe 1 or 2 times a season. it's not a great battery as i don't leave anything in my house of value. when i stay over night, i bring the good battery fully charged to run 2 in tandem.
a couple of things to think about:
It is always best to conserve juice when ever possible. Anything with a motor is going to suck juice, so like a cd player vs. just running an fm radio (cd player will drain your battery quicker), fancy flashing lights on a car radio shut them down, non-led lights, loud music, electronics, camera's, dvd players etc.....all suck juice rather quickly.
If you were going to only fish for 1 day a weekend and let it charge during the week, it would be alright. If you were going to fish 2 days in a row or more, you would want to conserve where ever possible. suxs running out of power.
I fish very long days on the weekends, both sat and sun. Sometimes during the week too. For my electronics, i use the batteries that come with them. Some times i bring an extra. when they die, then i hook them up to my 12 volt. Usually they get me through a day so i don't need to use my 12 volt. In the evenings, we either use candle light, which gives off plenty of light for cusk fishing or while eating dinner. When we get one on, we turn on the LED to see better (the wife and i) to land the fish. Again, conserving battery.
At night you only drain battery (no sun for the solar panels), so I save during the day as best i can too so i can have battery at night.
hope this helps.