need some constant power...

[NewFoundFreedom]

ok this is the problem. I have the fridge but it doesnt do much good if there is no power going to it. When the Sorento is off the 12V plug in is off also. I have bought another couple 12V plug ins to wire up but I need to make sure I am doing this right. All I need to do is run a positive and negative wire to it right? Should I have a fuse in there also? If so what size? Also I have two now to install and I could get one more (they match the factory ones) do I need more than two extras? I have four that run when the car is on and after this install I will have two when the car is off. One for the fridge and an extra. Do any of you guys use one more for anything else or just do hardwire for it? The only other things I can think of would be the ham radio which will be hard wire and the GPS which will be in dash. Anything I am missing? Thanks in advace.

 

[Mike S]

The short version ---

If you just need a constant 'ON' power supply, mount the 12V oulet, then select wire size one size larger than required for max load (amperage draw) and run (distant from the power source). The ground does not need to run back to the battery - it can be grounded to the vehicle locally. PUT IN A FUSE that exceeds the max power requirement of the load (fridge, or whatever), but is below the wire rating.

Example - your fridge may have a max amperage draw of 4 amps. Select wire one wire larger than the size required to deliver the 4 amps to the outlet. Insert a fuse that blows at, say, 5 amps. The fuse protects the wire and the load from damage.

 

[adventureduo]

What he said, plus your fridge should have a fuse in the back of it too.

 

[NewFoundFreedom]

:elkgrin: hey thanks guys! I love this forum!

 

[Robthebrit]

Standard practice is to assume a cig lighter socket can supply 15A. In the future you might add a spliter or use the outlet for something different, to prevent problems you should wire it and fuse it for this amount.

If its a decent length run I would use 12 gauge cable and use a fuse appropriate to what you are running, say 10A for a fridge. If in the future you want to take the max 15A from the socket you simply change the fuse to a 15 or even 20A and you wiring is ready to go.

It would be a shame to wire the socket to have a limit of 4amps specifically for a fridge.

Rob

 

[Rockcrawler]

Another good idea if you're going to be using the power port for several different items over time such as a compressor or some other high draw item is to put in a manual or self resetting circuit breaker rather than a fuse. It will still protect the circuit, but you won't need to be replacing fuses all the time if there are occasional high loads.

Kyle

 

[pete.wilson]

Hey

For power in my ambulance and will be again in my sub; is two series 30 trolling motor batteries supplying power to a 2200 watt inverter that could be left on or turned off since it came with it's own switch. The 115V output ran through a small junction box with circuit breaker/switches, this I used for a microwave and a refridgerator and also for charging plugs for keep various gear fully charged when on an outing. I also run 12v from the batteries to 3-4 outlets inside. I had a plug on the side of the vehicle where I could plug it in and a small onboard 1.5amp battery charger to trickle charge the two batteries. I used a small cigarette light digital meter to monitor battery voltage. A marine battery switch would allow no connection, single battery or dual battery operation (parrallel), use 4awg wiring from batteries to the inverter. You should be able to run everything witha good size inverter, mine came from Cabela's bargain cave for almost 1/2 price. Wire just like a house.
One reason I took this approach to power needs is so I wouldn't run the risk of draining my main starting battery for the vehicle, especially if I stayed in one spot for 3-4 days and running a bunch of electrical needs.....I didn't want to get stranded. A single battery and a 750watt-1,000 watt inverter would be good. Use the battery for your 12v needs and the inverter for the 115v needs. Hope this helps some.

 

[ntsqd]

One thing I repeatedly come across is a semi-cavalier attitude about grounding (earth). If the circuit isn't complete or there is a high resistance somewhere, the component won't function as desired. Frequently the ground side of the circuit is the problem.

I'm not saying that the previous posts are in error in any way, but I am saying treat the ground side with just as much diligence & care as the hot side. If belt and suspenders is your usual M.O. then run a ground wire back to the battery. Boats have to run dedicated grounding systems, and I don't think that lesson should be lost on us.

 

[Robthebrit]

what he said..

If you plan on running lots of aux stuff, run a large guage cable from the battery negative to a breakout box and wire things to the breakout box. Marine supplies will sell double breakouts which handle the positive and negative in the same unit. This gives only a single point of failure unlike the using the body which in the long run has all sorts of problems with corroision.

Rob

 

[Mike S]

I am a great belever in marine 12V products/systems philosophy for our exp vehicles. The problem with neg ground run backs to a battery or neg post is that you will have to run TWO wires, and the potential for abrasion on a critical wire is 2X the single wire risk. Additionally, a problem can occur with either wire in some inaccessible spot, making trouble shooting more time consuming. Marine appications require it due to grounding issues and elecrolysis. Standard automotive practice is local grounding. If you ground locally (assuming some intelligent practices for ground and accessibility) you can more easily trouble shoot a problem. Marine grade wire and terminations add reliability, as well.

My $.02 worth.