Wiring an inverter in a jiffy

[jpendoley]

I’m on a cruise and my partner needs to power her laptop and starlink for work. Bought a cobra 2000Watt inverter (no charger). Have a 450 amp bank of t105s. The inverter has (4) gfci outlets plus a couple of USBs. The inverter is about 6-8 feet away from the bank. I am thinking of direct connecting to the bank (I have a battery combiner that will isolate start and house banks during discharge). Really don’t want to undersized the cables-what are the gauge considerations for the connection to the house bank? Voltage drop tables suggest gauge ok but I am not certain. Any insights much appreciated

[mvweebles]

Here is a quick reference wire-size chart from Blue Sea:

https://www.bluesea.com/resources/1437

You need to calculate round-trip on the distance. 6-8 feet away from the battery corresponds to 12-16 feet circuit length. Next you need to decide how to size the cables. Personally, I'd size for the inverter load: 2000w / 12v = 166amps. You will need 1 awg cable at a minimum. You will need a 200a circuit protection on the positive cable. You could size for the laptop load, which is no more than 150W or so (~15A), but if someone plugs-in a microwave or something, you could fry your connections. A third option is moving the inverter closer to the batteries to reduce the 6-8 foot distance to 2-feet (4-foot round trip). You could probably get away with 2-awg cables, though I personally like heavy cables despite the expense: they are a one-time cost.

[CaptTom]

You might also look for a 12V adapter for the laptop. I found one for mine. Newer laptops with SSDs and no optical drive take less power than the old ones.

For the Starlink, I have no idea how much power it takes. But since you already bought 2000W of inverter, wire it up to a few outlets. You can run some other appliances like a microwave or coffee maker. You could even run refrigeration for a day or so without seriously depleting your 450AH bank.