Flat Trailer Plug

[Alphacarina]

WalMart sells a flat 5 pin trailer plug which may be a solution for anyone wanting to charge the teardrop battery off the car's electrical system

The first 4 pins are the exact same as any standard 4 pin connector, so you can still plug all your other 4 pin trailers into the new 5 pin connector on your car . . . . the 5th pin (the +12 VDC one) just doesn't engage the 4 pin plug on the other trailers because there is no pin there

The 5th pin is labeled for backup lights . . . . but I'm going to use it to connect the tear battery to the car's 12 volt system so it will charge the tear battery as I drive - It should also serve to run my mini fridge sitting in the back of the car off the teardrop battery, so it will stay cool when the car isn't running without running the car battery dead

Don

[jeepr]

That connector may be a little small for charging a battery. What is the wire running into the plug, around 16 gauge?

[Alphacarina]

Yes, same size as the ground wire too

I'm running a heavier wire before and after the connector. Keeping everything a #12 before and after the connector will negate much of the voltage drop - I don't expect my charge current to be all that much anyway

I just thought it was interesting (and handy) that 4 pin plugs will mate up with the 5 pin connector

Don

[jeepr]

I agree, real handy. As long as it will work. I have only dealt with larger travel trailers and they needed a larger gauge wire. I just hate to see the plug become the fuse. If everything is matched up size wise and fused correctly, it should be fine.

[brian_bp]

The same style of connector also comes with just two pins (these were supplied with my solar panel), and I think even some 6-pin rectangular configurations as well. Those combinations may not be as useful...

[brian_bp]

I would - okay, I do - just use 4-pin for my utility trailer, and 7-pin for my travel trailer, and have both connectors on the tug.

I think Don's approach is clever, and can work for a limited supply of power. I think it would make sense to use the heavy-gauge wire to limit loss, and protect the low-capacity plug connection by protecting the circuit with an appropriately rated fuse of circuit breaker - what's that, 10 amps?

Another approach would be to leave the 4-pin connections alone, and run power on a separate two-pin connector, with its own "ground" connection. This is the approach taken in Europe (although in their case both plugs are 7-pin), and avoids overloading the negative ("ground") conductor and contacts. Too bad it would be one more thing to do at hitching and unhitching times.