Bavaria 40: Installing USB plugs in cabins?

[Krumelur]

I want to install USB plugs in my boat's cabins. Has anyone done this and can share their experience?

I'm thinking of drilling holes into the cabinets bottoms in the front cabins and into the storage places in the aft cabins and put either double USB-C or USB-C/A adaptors in there.
From those plugs I wanted to run wires of to the nav panel and use one of the free F-buttons to power all plugs. I reckon, the F-switch would toggle a relay which in turn would power the USB plugs?

I'm looking for assistance with:
- Recommend USB plugs that don't corrode within week's time :-)
- What kind of wiring should I use? Is there specific marine-approved wiring?
- What kind of relay do I need? Again, is there marine-style electric components?
- Any insights how to connect something to the nav panel's F-buttons?

I'm fine with working with electric components but am unexperienced when it comes to boat projects. I want to use the right components to avoid corrosion and other issues.

[Jake]

Blue Seas have a selection of USB plugs.  I installed one at my nav station.  The current usage is very low.  You could probably use 16 gauge wire, unless the run was very long.  Make sure the wire is tinned, so it won't corrode.

Jake

[SorinCT]

First of all what are you planning to power with the outlets? If normal use (phones, tablets, etc) i don't understand why you need a relay to switch them on as the amperage is low (1-2-3 Amp). Just make sure that the fuse is adequately sized.

It's worthwhile to get plugs with On/Off switches as they incorporate DC-DC converters (to step down voltage) and even while not in use they use up some power.

[Krumelur]

More and more devices have USB C connectors. I want to power devices like the Nintendo Switch, my MacBook etc.
That’s why I was thinking relay. I must admit: I don’t know how the switch panel in the Bav works (the soft buttons). What currents are they designed for?


Good point on the DC conversion!

[symphony2]

The fuse sizes for each switch are shown in the diagram in the handbook.

[sunshine]

The ones with a little LED are surprisingly bright at night in a cabin. You can obviously put black tape over it, but I went for the blue sea ones without the LED.  They are more expensive but can apparently sense the current required and alter output accordingly. Certainly charge phones and ipads much more quickly than a USB converter plugged into the cigarette lighter. Powered them from an F button, but put an inline fuse in anyway so that a wiring short doesn't overload the panel ( ithink only F4 and F5 have fuses on the board, which you can swap out for lower rated fuse if desired). F1-3 are rated at 5A so if you are adding a few of these you could go over this if all are in use at the same time (each USB had two sockets).

If you use the correct sized holesaw (19mm I think but worth checking) you get a neat finish.

[Krumelur]

What's behind the F1 buttons? (Sorry, I'm not at the ship at the moment).
I mean, they aren't physical switches, are they? I had the impression, they toggle a relay?

[sunshine]

F4 (15Amps) and F5 (20Amps) are switched through a relay. Not sure about F1-F3, I think they may just be switches.

[Krumelur]

Ended up ordering some parts from a ship in Germany: 20m of tinned wire (2.5 square mm), 10m of tinned wire (6 sqmm) and 6 USB A/C combined plugs.

First, I had "PHILIPPI" USB plugs for €27 each. Then I thought: that's a typical made-in-China thing, isn't it? So I went over to AliExpress and found a version that had a a) a built-in switch to turn it on/off and b) a cover to protect it - and it was only €9.

60W PD Type C/QC 3.0 USB Charger with Switch Socket Power Outlet Adapter Waterproof For 12V 24V Car Truck Boat RV Motorcycle (https://www.aliexpress.com/item/1005003258307265.html?spm=a2g0o.productlist.0.0.4b2a2d05bGSQ9b&algo_pvid=fe73cdca-8ae4-40ee-8e98-cf8902407887&algo_exp_id=fe73cdca-8ae4-40ee-8e98-cf8902407887-3&pdp_ext_f=%7B%22sku_id%22%3A%2212000024889437382%22%7D)

[SorinCT]

Are you planning to put 2.5 sqmm wire to feed the plugs? To me it sounds excessive. You have a max of 2.5 A on 12V which would require 0.75 mm2 for lengths up to 30-40 feet. That 2.5 mm2 wire is severely overkill.

[Baltic]

"You have a max of 2.5 A on 12V which would require 0.75 mm2 for lengths up to 30-40 feet. That 2.5 mm2 wire is severely overkill."


https://www.wirebarn.com/Wire-Calculator-_ep_41.html
https://www.fabhabs.com/dc-cable-sizing-calculator

I would like to say...
2.5mm2 minimum.

[Krumelur]

I also found 2.5 to be recommended using a calculator.
USB C can go up to 4A and no harm done using thicker wires.

[SorinCT]

I also found 2.5 to be recommended using a calculator.
USB C can go up to 4A and no harm done using thicker wires.

4A on the output maybe?

[Krumelur]

I don’t follow. What are you trying to say?
3A at 5V equals to 15W per USB plug.
I need to power 6 plugs on that wiring installation.
Not all will always be used und certainly not at max power but I don’t see 2.5 wiring as a wild exaggeration?

[SorinCT]

Are you planning to run individual circuits for all plugs or they are getting daisy-chained?
3A @ 5V = 15W (output) = 1.25 A @ 12 V (input). If all the plugs go on the same "busbar" then the amperage adds up, let's say 1.25A / plug. If you are wiring in parallel, you will have 1.25A / cable.
There is no detriment in going for a higher grade cable but I don't see the point.

[Krumelur]

Yes, as I wrote, all are going on the same bus, adding up to 6x1.25A = 7.5A.

[Impavidus]

A real quick way to fit dual USB sockets is to use the existing reading lamps circuit. Wire 1 x USB outlet in parallel the type that has a 1.5 amp and a 2.1 amp max outlet. This lighting circuit is wired in 2.5mm2 cable as the factory reading lamps are Halogen. (Certainly on our 2015 B37)
Swap these bulbs for LED And then fit a 2 outlet type USB socket from ebay. The USB ports will then not exceed the rated load of the halogen even if the lamp is on. When the light is off the twin port USB stays on. Both the relay and the fuse rating are not exceeded as long as you fit the LED bulbs. 

Just be aware that some of these USB outlets have a blue LED lamp that indicates they are on. It's very annoying and quite bright during the night.
Sail Safe Guys, Ant, Cid & the pooch crew.