Help a Noob; Adding a 12V outlet

[Pinecone]

Hi I'm new to the scene in a manufactured Pinecone teardrop from Three Feathers Mfg, acquired 2 months ago. I want to add a 12V cooler in the galley area.

The galley already has a 12V switched DC lamp as well as an AC outlet when hooked to shore power. I want to add a 12V outlet in the galley so when I'm not hooked to shore power I can plug the cooler into the 12V socket. I will need to add a small air vent also.

I've added outlets in a home before. Simple process of turning off the power, tapping off an existing outlet, pigtailing the wires together, and running romex to the new box. My question to the forum: Is it the same process in an RV using 12V wiring? My thought is to tap power off of the existing 12V lamp. Before I get started splicing wires I thought I should ask so I don't melt my TD or blow anything up.

Also, any advice on a battery charger? I was thinking about getting a portable one so that it will work on my TV in an emergency, or to loan to other teardroppers who want to charge up their batteries when AC is available. http://www.amazon.com/gp/product/B000BQSIWK/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

Thanks for helpful advice!
Greg

[GuitarPhotog]

A couple of things:
1. How big is your trailer battery? You need to know how many Amp-hours it stores.
2. How much current does the 12V cooler draw?
Those two numbers will tell you how long your battery will run your cooler.

Keep in mind that those 12VDC coolers do not cool much (any) lower than 40F below ambient. So if the cooler is in 90F ambient temps, the inside temp won't get much below 50F, which is well above the food safe range of <40F.

I don't find power consumption figures for any of the 12 V coolers listed on Amazon, but most come with a 5A 12 VDC adapter, so it's fairly safe to assume a current draw of less than that (~60W).

The general consensus around here seems to be that 12 V coolers are not suitable for use in/with a teardrop because of cooling limitations and power consumption.

<Chas>

[Pinecone]

Hey Chas - thanks for the perspective! I have a 100ah battery and plan to put the cooler in my TV while driving, and in the teardrop only on occasion. Having the 12V outlet in the galley there gives me options like the cooler. As well I installed a sound system in the galley that can be powered via 12V, but I need an outlet back there for that also.

So, my main question is about adding the 12V outlet in the galley by tapping power off the DC lamp, not necessarily about the cooler.

Thanks for your help and advice. I will think again about the cooler.

Greg

[working on it]

Also, any advice on a battery charger? I was thinking about getting a portable one so that it will work on my TV in an emergency, or to loan to other teardroppers who want to charge up their batteries when AC is available. http://www.amazon.com/gp/product/B000BQSIWK/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
Greg

I thought the same thing when I chose to use a removable automotive/marine battery charger/maintainer in my trailer (instead of the recommended by most, built-in RV converters). I chose another Schumacher product,http://www.walmart.com/ip/Schumacher-XCS15-15-10-2-Amp-Marine-Battery-Charger/15140196. I had battery problems that I, at first, attributed to the unit, but eventually learned the proper way to use it with my AGM battery, and not to leave my inverter hooked up at all times. I did post an FYI post on the XCS15, http://www.tnttt.com/viewtopic.php?f=30&t=55957&hilit=+xcs15 and so far I'm happy (again) with it. I believe in always being able to use items for more than one job...this one can. Here's a long thread with my "battery / charger / 12v system" problems detailed, among other info. http://www.tnttt.com/viewtopic.php?f=30&t=55957&hilit=+xcs15#p1015132

[Shadow Catcher]

The Coolers draw about 4.5 amps continuously as long as they are on, so a substantial load. Your being able to tap into existing wiring depends on its gauge/size and what load it has. Our Waeco refrigerator rides in the back of the Subaru powered by the alternator. Subaru has a power point in the back but it is powered only when the ignition is on so I ran a 10Ga wire to the battery. I really dislike the conventional lighter type 12V plugs so replaced them with Anderson Power Poles including the one in the galley to power the refrigerator.
Other than for cooling the beer or other beverage of choice the 40 degrees below ambient temperature means I would not trust this type of cooler to store meat or other perishables it is just too dangerous.

[rowerwet]

to get to your original question, you can splice in, however with DC it is important to get the polarity right.
Use a volt meter and make sure you know which one is the positive wire, it needs to go to the center of the lighter socket.
for the splice a soldered connection is the best, wrapped in quality electrical tape, a butt splice is ok, those "suitcase" snap on connetors are prone to corrosion and loosening.
make sure your wiring can handle the power you want at the plug, lighting wires may not be a heavy enough gage. (and majic smoke my escape)

[Pinecone]

You all have been very helpful.

So, let's say that the max amps I would be drawing in the galley is 8-10 amps at any given time. At that point I think I shouldn't tap power off the galley light fixture (wires may be too small) and should run a new wire directly from the battery to the new 12V socket. Does anyone know what gauge of wire I would use? Also, what size fuse would you put in the line?

I am learning lots, thanks again!

[GuitarPhotog]

You all have been very helpful.

So, let's say that the max amps I would be drawing in the galley is 8-10 amps at any given time. At that point I think I shouldn't tap power off the galley light fixture (wires may be too small) and should run a new wire directly from the battery to the new 12V socket. Does anyone know what gauge of wire I would use? Also, what size fuse would you put in the line?

I am learning lots, thanks again!

I suggest a 10A fuse and 14ga wire. Both will be sufficient for 8-10A loads. Put the fuse at the battery end.

<Chas>

[Pinecone]

Thanks for the help Chas. Why do you put the fuse at the battery end?

[GuitarPhotog]

Thanks for the help Chas. Why do you put the fuse at the battery end?

To protect the circuit in case the wire becomes frayed/broken and shorts the battery to ground.

<Chas>

[Pinecone]

OK, thanks for the advice! I'll start working it up!

Greg