Adding Electronics To The Truck

Newbie driver reporting in.
And putting my dues in with one of the the big name companies.

I'm looking to just put in a minifridge and be able to plug in my laptop.
When I was in training, my trainer mentioned switching the fuses to a higher, uhhh, amp rating (?) for ports I want devices plugged into.
I went to a terminal's shop and they just handed a few "30" fuses to me, saying they're the highest ones they have--I can do it myself. Gee, thanks...

I'm currently in a 2012 Kenworth T660.
If I understand correctly, the truck has 3 different sets of fuses, but the ones I should be interested in are the ones located by the clutch, right?
So at this point...I should...? This is where I'm not certain of things. Do I just simply pull out the fuses and put in new ones? Since I'm only looking to swap in two new fuses...should I just stick in a phone charger into the ports and see which one isn't working, while a fuse is removed, to see which fuse connects to which 12v port?

I'm just looking to stick a cheap 12v plug in fridge into the truck (I'm aware that I should unplug it during hometime), as I don't plan to stay with this company for very long (it took nearly a month to go from a terminal in California to their Pennsylvania one! I sure did enjoy being stuck 5 days sleeping on a recliner and not being paid...).
As for my laptop...apparently, inverters and converters are prohibited by company policy. And yet, one of the terminal shop foremans said to use an inverter to hook up a fridge.
I'm just going to buy one anyway. It's not hard to unplug a basic one whenever I leave the truck on company property. And big deal if they find out I have one...by the time they do, I'll get a slap on the wrist at most, and I'll be long gone from the company before they actually do anything. So, what Watt of an inverter should I get for a laptop? Looking at the charger, it reads (Input: AC100-240V-, 50-60Hz, 1.5A) and (Output: 19V 3.42A).
Does that mean I should find an inverter that reads "12V DC to xxxV AC?" And the xxx can be anywhere from 100-240? Is there a Watt rating that I can look for that is equal to the AC one?
The output of the charger should be no concern to me, right?

I have little electricity knowledge, but I was using this site to try figuring some things out:
http://www.batterystuff.com/kb/tools/ac-to-dc-amperage-conversion-run-through-an-inverter.html

So, if I'm understanding this all correctly...
My laptop charger has a 1.5 AC Amperage. It is compatible with anywhere from 100-240 AC Voltage. That means 150 to 360 Wattage, which seems to be very low-end of what most Inverters/Converters are rated.
And going through the 12V DC, it'll require 13.8 to 33.12 DC Amperage. So, as long as I don't get an AC Voltage higher than 217, the DC Amperage will stay under 30. And since in the US, pretty much everything is 100-120 AC Voltage, I shouldn't have much to worry about once I stick in those 30 Amp fuses.

Is this all correct that I'm doing and calculating?
All input would be greatly appreciated!

 

I see, "weakest link in the chain" issue, huh?
Any idea what the 2012 KW would have for the wire size/capacity?
Safe guess would be whatever amp is the default in there. But I know this truck has been totaled to Hell & back and out of commission for at least a year before they forced me to take it, so I can't know for sure what the original fuses' amps were at, unless they would be listed somewhere in the owner's manual. Between previous operators and repairs, it's hard to know if those fuses in there are standard or not (be it too high or too low). Plus, there is always the fact that sometimes manufacturers do nonsensical things...they could put in default fuses of 10 amps, while those wires can handle 25 amps. Vehicle manufacturers sometimes do dumb things like that. But based on how you say truck manufacturers have been trying to up the capacity of the wires, I suppose this likely isn't the case. Concern just lies on figuring out what the original fuses are, and possibly the wire's capacity.

Of course, based on the numbers/calculations I came up with, I can't see how I could ever get anywhere near using the 30 amps, unless I was intentionally trying to heavily overload a port, haha.

Good to know. My trainer wasn't exactly the most knowledge person when it came to automotives. I'm guessing he was passed some bad info from a not so experienced shop guy at one of the terminals (after all...the one shop just handed them to me and gave me no warning!)
Based on what I just learned about electricity & batteries, just about any 12V little fridge that I can find at any truck stop or Home Depot should be plenty fine with the standard fuses. And it looks like the AC plug will be a max of 120 by being in the States, and the 1.5A plug, the max Wattage I'll actually need for the laptop is a measly 180.

However, the DC amperage needs to be at/above 16.56.
If the fuses in my truck are at 15 Amp...would I be fine just using that port until it blows and then just switch in a new one? lol No cost to me...company just hands me fuses without question. Or would that eventually cause issues (keep in mind I'm likely only in this truck for another 2 months tops)?
Or, for this port, should I just stick in one of those 30 Amp fuses? I wouldn't be drawing on all of that power. Only 16.56 amps worth. Would the wire be fine with that? Keep in mind that I won't have the inverter plugged in constantly. Just for around an hour at a time (0-2 times at most each day) to charge up my laptop, and then I'll be unplugging the inverter.

Perhaps I should just try out the fuse in there currently, and if it has any issues, swap in the 30 then? Or grab a 20 next time I have a chance and use that one (or a 17 if they exist, heh)?