Combination Berth Light and 12V Outlet ?

[Jd1]

I would like to install a couple of 12V outlets near berths to plug a laptop computer into. I would rather not cut holes in the boat. Is there such a thing as a light fixture that has a built in 12V outlet that I could replace an existing fixture with?
It seems that it is a natural idea but I have yet to find one via google maybe I am not using the right search term?

[belizesailor]

Don't know of a specific light/outlet product, but would be easy just to drop a female 12V outlet or two off most fixtures. However....

I would check your existing installation first. Light circuits are often installed assuming small loads. What rating is the breaker? Gauge of wiring? Distance of wiring run? Load (in AMPs DC) you plan to connect? Some laptops draw a surprsing amount of juice.

[mitiempo]

12 volt outlets are usually rated at 10 amps maximum. You have to wire for the maximum possible amp draw. As posted the wire size will depend on distance.

As far as installing without a large hole some are available for surface mounting, so the only holes required would be for the attachment screws and the wiring if it wasn't surface mounted. Trotac in Victoria has them.

[Boracay]

Initially why not run an extension lead to your laptop? Make up a 12V one if necessary.

A laptop, particularly when charging a fully discharged battery will take a fairly large current draw for quite a few hours. 12V wiring for this would need to be properly sized. If it were me I'd make it quite substantial.

My understanding is that each laptop needs a different voltage so unless you're using a DC-DC converter the 12V system may not suffice.

I've found that most computer use takes place in the marina so marina power is used. Those very few times that I've needed to recharge the batteries of my laptop I've used a small 300W inverter and the laptop charger.

If flexible use is that important why not use a tablet? Many have excellent battery life (way past that of a laptop) and if charging is needed then an inverter matched to the charging supply would do the job. There are many different types so matching one to your needs may not be that difficult.

I've used cigarette lighter sockets and plugs from a reputable maker for my 12V outlets. Poor quality ones are certainly not up to the task (don't ask...).

[belizesailor]

Originally Posted by Boracay

...


My understanding is that each laptop needs a different voltage so unless you're using a DC-DC converter the 12V system may not suffice.

...

Most I've used aboard had 19 to 21V DC input and so required a DC-DC power supply. I've tried a couple of diff DC-DC power supplies and not had good luck with them (all had short lifespans here in the tropics).

So I just charge laptops from the inverter as well.

Anyone have a make of DC-DC power supply to recommend that has faired well?

[Ketchgould]

The whole required for a surface mount 12v receptacle isn't that bad. Use a Forster bit and get a nice clean install in a few minutes. This also allows you to put the receptacle right where you want it and to wire it properly.

[Jd1]

A bit of further info:
I do have a DC-DC converter That I purchased for this purpose (and a spare)
I use the laptop for anchor watch so it has to run for long periods - battery life is only about 4 hrs. I have used an inverter but would like to reduce my power footprint.
I am also thinking it might be nice to have a 12V bunk warmer pad at some time.
I will be checking the wiring and fusing to see if it is up to the job but if it is in fact sized for 10 amps it will do the job nicely, The bunk warmer will require 6 amp max and the laptop takes about 2.5A max. I might have to convert to LED bulbs for the lights but that is in the long term plans anyway.
Once I determine the utility of going this way, I don't mind installing permanent outlets (and a seperate wire run) but figured that it would be easier to try things without making holes first (I HATE making new holes in my toy!)
I will probably end up with a surface mount unit with double sided tape for mounting during the trial period (thanks mitiempo). It will just hook into the existing light fixture for now (if wire and fusing is ok)

[Paul Elliott]

Originally Posted by belizesailor

Most I've used aboard had 19 to 21V DC input and so required a DC-DC power supply. I've tried a couple of diff DC-DC power supplies and not had good luck with them (all had short lifespans here in the tropics).

So I just charge laptops from the inverter as well.

Anyone have a make of DC-DC power supply to recommend that has faired well?

I have used Lind converters with good results: Auto Power Adapters and Cables | Lind Electronics
The 12V models operate over a 11-16V input range.