Not really a battery issue, car batteries have at least 400amps available for starting the engine.
What you need to consider is the alternator, it runs the electrical system when engine is running, and if you exceed its amp rating then battery will drain while you drive, instead of charge, leading to a no start from dead battery.
Find out what alternator you have for your year, engine, and model, get its AMP rating
Generally if your alternator is rated as 80amps then stock truck electrics with everything ON, will draw 1/2 those amps, so 40amps
An alternator can only put out 60% of rated amps at idle RPMs(650-750rpm), it only has full rated amps above 1,800RPMs.
Then go here:
http://rapidtables.com/calc/electric/watt-volt-amp-calculator.htm
Enter watts and volts(12) then Calculate, and you will get the AMPs for each device you want to add
So what you may want to do is get a higher rated alternator, they go up to 200AMP rating, so 100AMPs would be available at idle.
AMPs are a "draw" so 200amp or 500amp(lol) alternator won't hurt battery or electrical system, it only outputs the AMPs required at any given time, so as you turn things on voltage regulator in alternator increases amp output, IF IT IS AVAILABLE.
So maintains the engine running 13.5-14.5volts, if you exceed the available amps then voltage drops, i.e. dimming headlights at idle is an example of exceeding alternators available amps
ANYTHING connected to vehicles power system needs to have a FUSE, and fuse size is determined by the device being powered AND(big and) the WIRE SIZE used.
If you use a 20amp fuse on a small wire to the device then the WIRE becomes the fuse, if there is a short or ??, then wire heats up and melts or starts a fire, instead of the fuse blowing.
So check 12volt wire size, length of wire and rated amps, there are charts for that, it is important
All a fuse is, is a smaller wire that melts when heated, lol.