12v only power questions

[optimizer]

Hi!

I started my build yesterday and am confused about the electrical portion. It's several days away but I'm hoping someone can answer my questions or point me to a thread that already does.

The plan for my teardrop (ROLBAK) is to have only battery power to the cabin and galley. I don't plan on using it in a campground and don't want to deal with the shoreline portion. So - I'll have a deep cycle battery in a battery box on the tongue and wire that up for the interior power.

Inside, I'd like to have:
- a few (2-3) small lights - nothing terribly bright
- power outlet with 3 prong and USB slots
- power outlet for a small TV and DVD player

Ideally these outlets will all be the same type you'd have in your home - as I'd like to use standard stuff in the trailer (like my laptop and a TV). So ... can I use normal outlets and just wire them to a fuse box that is wired to the battery? Or do I need an inverter or converter to do this?

Any advice, links, etc. greatly appreciated.

Ansley (aka Optimizer)

[mrwall1]

I am not very knowledgeable about electricity myself... so I wired them separate.. I have outlet boxes for 12 volt, and I ran separate wires to outlet boxes for 110 with shore power....
I was thinking the same as you but I am pretty sure you would need an inverter to run the TV and Laptop... the lights, fan could run 12 volt fine... we ended up just using the LED battery operated lights inside, and solar on the outside, and have plenty of light!

good luck!

[Dale M.]

IF you are going to use 12 volt DC, use sockets appropriate for voltage.... Generally referred to as cigarette lighter sockets as used in car ( some are even called "accessory power sockets" to get away from the "cigarette" thing) .... Many laptops and phone charger system (USB) as used in car will then work for you with no modifications to cords or plugs.... IF you intended to use a 120V AC TV or coffee pot, it will require a inverter to convert the 12V DC to 120V AC.. You need to keep power systems separated, so for 12V DC stay with appropriate plugs and for 120V AC stay with standard home receptacles... You have all receptacles the same and not clearly marked as to voltage or you accidentally plug device into wrong receptacle you will let the "magic smoke" out of device and it will no longer work...

With a proper inverter you can also charge the battery when at home or have shore power... You may also want to look at "charging while towing" or solar if you do extensive boon-docking without shore power...

Simply its easier to use proper receptacle for designed voltage than having to fix "things" after a goof up in plugging something in wrong..... There is so may plug/sockets and appliances today that run on 12V DC the is no reason to play guess what voltage is at the receptacle...

Dale

[High Camp Trailers]

Hi Optimizer,
Dale's right on with using the correct outlets, definitely not advisable to mix n match. I may be wrong, but it sounds like you intend on running AC (110 volt household) appliances off of the deep cycle battery. If that is the case, you need to calculate what the power draw of those appliances will be and figure out what size deep cycle battery you will need to power them. You may find that based on your expected use of those appliances (amp hours required) that you will need several very large/expensive batteries in order to power them through an inverter. The electrical system is something that should be fully planned out on paper before you snip your first wire (particularly if you haven't done electrical work in the past). You need to know what all your appliances will draw every hour, figure out what size battery you need based on how many days you want to be able to camp between recharging the battery, you need to know what wire gauges you will be using for each circuit and have the proper fuse size to protect the smallest gauge wire in any given circuit, etc..., etc...
Take my advice and write it down before you build... there are many great books to help, but this is one that I particularly like... "Managing 12 Volts: How to Upgrade, Operate, and Troubleshoot 12 Volt Electrical Systems "
About $15 on Amazon prime, or check you local library.
Best- Dennis

[tony.latham]

I'll suggest a couple of things. First of all, start your 12V system around a fuse block such as this: http://www.amazon.com/Blue-Sea-Systems- ... e+fuse+box

As far as the DVD player and small TV, I'd suggest you just buy a portable (12V) DVD player with screen and wire in a cig plug for power. Any time you are turning 12v power into 120V power you are losing energy at the inverter. http://www.amazon.com/Sylvania-SDVD1332 ... dvd+player

We do not have anything other than 12 volts in our tear. Runs the fan, hatch light, interior light, USB charging ports, Fantastic Fan, cig plug ports for (12V) electric blanket and portable DVD player. Boondock camping! Sweeeeeet.

Tony

[MtnDon]

Nice fuse block. Too many do not include a negative buss; that one does.

[optimizer]

Thanks for all the helpful information everyone!

I'm going to hold off on an inverter for right now - I have one I keep inside the Jeep anyway and if I absolutely need it, I can plug it into one of the 12v sockets for my laptop or a small TV.

I ordered 12v lights, sockets and an electric blanket last night - will look around for the fuse block and wiring locally next. We're a few days away from wiring but it's coming together well!

Thanks again!
Ansley (aka Optimizer)

[LandCommander]

Sounds like you have it figured out. Use 12v appliances and use the little inverter you have for your laptop. Don't worry too much about fuses and wires, just have at least a fuse at the battery and use a heavy gauge extension cord for wires. And i would reccomend a plug-in battery smart charger aka a *converter. If you already have a trickle or battery charger that will do. I would also reccomend a small solar setup if you plan on staying in one place for more than couple days.

[optimizer]

Hi everyone,

So I ordered the 12v fuse block from Blue Seas that Tony mentioned (http://www.amazon.com/Blue-Sea-Systems- ... 745&sr=1-1). I have all of the wiring (12g) for the cabin lights (12v LEDs) and sockets (cigarette lighter style) running into my raceway. I have a deep cycle marine battery in a box on the tongue and ready to connect. I also ran a ground wire from the trailer frame up into the raceway.

I was originally following the Generic Benroy plans posted on this site but since deciding to go 12v only I'm confused on the plans. Specifically, where do I connect the ground wire? (One end is attached to frame - where's the other end go?) Some designs I see show it attached with the negative from the battery. Others show a bus bar/block. If the ground does need to attach to a bus bar - do I then also run the battery + and - to the bus bar and then run those also from the bus bar to the fuse block?

Thanks!

[tony.latham]

Hi everyone,

So I ordered the 12v fuse block from Blue Seas that Tony mentioned (http://www.amazon.com/Blue-Sea-Systems- ... 745&sr=1-1). I have all of the wiring (12g) for the cabin lights (12v LEDs) and sockets (cigarette lighter style) running into my raceway. I have a deep cycle marine battery in a box on the tongue and ready to connect. I also ran a ground wire from the trailer frame up into the raceway.

I was originally following the Generic Benroy plans posted on this site but since deciding to go 12v only I'm confused on the plans. Specifically, where do I connect the ground wire? (One end is attached to frame - where's the other end go?) Some designs I see show it attached with the negative from the battery. Others show a bus bar/block. If the ground does need to attach to a bus bar - do I then also run the battery + and - to the bus bar and then run those also from the bus bar to the fuse block?

Thanks!

Opt:

Use the photo of your fuse block on Amazon as a reference.

On the top and bottom of it, you can see there's a stud and a nut. The top stud is the negative and the bottom is the positive. Run a 10 ga (black) wire from the top to the negative side of your battery. Run a 10 ga (red) wire from the bottom of the fuse block to the positive side of the battery, but just short of connecting it, put a 30A inline fuse holder like this: http://www.amazon.com/Ato-atc-Inline-Fu ... nline+fuse

There's a couple of different philosophies on whether to ground the frame or not... but that's beyond your thread.

Tony

[optimizer]

Thanks Tony. Is there another thread you could point me to regarding the ground? That's really the information I'm looking for at this point.

[tony.latham]

Thanks Tony. Is there another thread you could point me to regarding the ground? That's really the information I'm looking for at this point.

Here's one: viewtopic.php?f=30&t=60353&p=1096755&hilit=grounding#p1096755 But there are more out there.

It's more of an issue focused on the chassis lights, not the cabin. I'm assuming you are going to charge your battery while towing? When you hitch your trailer to your vehicle, it's in theory "grounded" via metal to metal with your tow vehicle (the negative cable on your car bolts to the frame). A preponderance of trailer light problems are caused by bad grounds. For an almost foolproof chassis light system, each (taillight etc) light needs to have a dedicated ground wire.

You should have a ground wire coming from your tow vehicle and connecting to your trailer lights and the negative side of your cabin battery. The positive side of your cabin battery only connects to where ever in your cabin that you need juice (through your fuse box).

So... you really don't need nor really have to ground your cabin battery to your trailer frame. Just run a black and red wire to each electrical need and protect it with a proper fuse in your fuse box (red wire down there in your fuse box by the fuses and a black wire up there on the sides on the top). For most 12v power needs in our short teardrops, 14 ga wire (and 15 amp fuse) are fine.

Capish?

Tony

[optimizer]

Understood, thanks for elaborating!

I've already run separate grounds for all of my tail/running lights from the ground on the tow harness where it screws to the frame/tongue. The DOT lights are already all operational and fine. I'll run another of those ground wires to the battery negative and then run the battery +/- to my fuse box and wire +/- from there for my cabin/galley lights and outlets.

Thanks again Tony!