How many amps to run in fuse

Can someone tell me what amp to run in my sub fuse panel for this product I’m installing in the bed?

[2022 Newest] Kohree 12V Power Outlet Socket, 3 In 1 200W Cigarette Lighter Socket with PD Type C 3.0 & QC 3.0 USB Charger Waterproof for Marine, Car, RV, Motorcycle, Boat, Golf, ATV, etc

$17 [2022 Newest] Kohree 12V Power Outlet Socket, 3 In 1 200W Cigarette Lighter Socket with PD Type C 3.0 & QC 3.0 USB Charger Waterproof for Marine, Car, RV, Motorcycle, Boat, Golf, ATV, etc

https://www.amazon.com/dp/B09CKQJQDT

 

If it is 200W, I would use a 20 amp fuse. (200W divided by 12 v = 16.67 amps)

And make sure the wire is capable of the current--12 gauge, probably.

 

12 amps, ensuring that all the wire feeding it will support that amperage.

You always want your fuse to be the weak point of the system. Here your system (from the fuse panel back) includes the total max current draw of the devices, the panel itself, and the wiring run.
You can size your wiring with this chart: https://www.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg
Max advertised current draw is 200W + 36W + 18W = 254W = 19.5A
The panel itself has a 10A rating, and comes with a 15A fuse. I'd be hesitant to up-rate that without seeing the quality of the panel in person; the switch will be the most likely failure point if you run new wires. I also generally only overfuse by 10-25%, not 50%.

Making the fuse the limiting step, and making some assumptions about your wiring, 10 ga wiring and a 12A fuse. I'd expect to only use this particular panel for 10A/120W.
That's also likely enough wiring beef to protect you if you choose to throw a larger fuse in and run it at what its likely capable of rather than what it's rated for.

 

I was going with a 10gauge with a 40amp fuse and then at the sub fuse panel a 10 amp for the 12v socket, usb and voltage meter.

 

Sounds like a solid plan. Don't forget that you can halve your wire run by grounding to the body, and enjoy!

 

^ x2 on this advice
100%
Fuse should go first, everything else should be rated to handle well over the amperage the electronics are rated for. Also: check your instructions or the product specifications. They should list the amperage the thing is rated to handle.

 

That’s not how this works. Fuse/breaker protect the wire, not the other way around. Electrical fires are no joke.