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power from jeep to trailer

PostPosted: Wed Apr 03, 2019 1:22 pm
by yycwrangler
When getting the jeep hitch installed, I asked them to run an isolator and wire for 12volt through to the trailer. So currently I have power to the 7 pin plug. On the trailer side, what do you do to run the power the rest of the way into the trailer..Most likely through any wire opening already in trailer. Which pin do you use on the trailer side and do I need to ground the trailer (I'm thinking so). How about if the trailer is all aluminum.

Any help would be great

Al

Re: power from jeep to trailer

PostPosted: Wed Apr 03, 2019 2:06 pm
by John61CT
How many watts (amps @12V) will the connection need to carry?

If you've no idea, list the load devices, batteries, charge sources etc at each end to help derive a ballpark estimate.

For anything significant, a pai of Andersons works much better than the pins on a trailer plug.

Also need properly sized wires, depends on distance and devices' sensitivity to voltage drop.

Re: power from jeep to trailer

PostPosted: Wed Apr 03, 2019 2:19 pm
by onehoser
this might help

Re: power from jeep to trailer

PostPosted: Wed Apr 03, 2019 4:08 pm
by beachguy005
Does your trailer have a 4 or 7 pin connector?

Read your other post mentioning breaks so I'll guess you have a 7 pin on your trailer. One of the pins will be marked "aux" which is what you use. There's probably a wire on that pin going back into the trailer already.

Re: power from jeep to trailer

PostPosted: Wed Apr 03, 2019 7:03 pm
by bdosborn
onehoser wrote:this might help


Image

It might help start a fire, a #10 wire with 85A is dangerously overloaded, no matter how short the run.
Bruce

Re: power from jeep to trailer

PostPosted: Wed Apr 03, 2019 7:33 pm
by John61CT
Yes toss that chart, very dangerous.

Blue Sea' Circuit Wizard is my reco

Re: power from jeep to trailer

PostPosted: Thu Apr 04, 2019 12:46 am
by yycwrangler
Thanks guys for the feedback. The line would be used to just charge my battery pack which supplies power to my led light and that's about it. The other thing I have is an ebike and if I could figure out how to connect that via 12 volt it would nice to charge that while travelling. That being said, in the jeep it has one of those 120v outlets where you can plug a home appliance into it. Have used it for my laptop etc. I don't think you put anything with a large draw on that outlet. But it might be the ideal thing for the ebike battery

I will check and see if the trailer plug does in fact show a aux spot and fingers crossed that it's already got wire running from it

Cheers
Al

Re: power from jeep to trailer

PostPosted: Thu Apr 04, 2019 12:47 am
by yycwrangler
Thanks guys for the feedback. The line would be used to just charge my battery pack which supplies power to my led light and that's about it. The other thing I have is an ebike and if I could figure out how to connect that via 12 volt it would nice to charge that while travelling. That being said, in the jeep it has one of those 120v outlets where you can plug a home appliance into it. Have used it for my laptop etc. I don't think you put anything with a large draw on that outlet. But it might be the ideal thing for the ebike battery

I will check and see if the trailer plug does in fact show a aux spot and fingers crossed that it's already got wire running from it

Cheers
Al

Re: power from jeep to trailer

PostPosted: Thu Apr 04, 2019 7:21 am
by John61CT
yycwrangler wrote:The line would be used to just charge my battery pack which supplies power to my led light and that's about it. The other thing I have is an ebike and if I could figure out how to connect that via 12 volt it would nice to charge that while travelling.
"Just"? LOL! Battery charging is potentially **much** higher currents than anything else.

And **highly** variable depending on the specific batts.

Engineering very fat cables with Andersons is not rocket science but in this case I advise against DIY that approach.

Get a solid DCDC charger in the trailer to limit current and feed correct voltage.

The boost converter / PSU needed for the eBike can use its output as well, if it does not have configurable current limiting of its own.

Size the main cabling conservatively according to the charts after determining the max current.

I very strongly advise skipping the trailer plug and putting in Andersons for that circuit.

Re: power from jeep to trailer

PostPosted: Thu Apr 04, 2019 8:53 am
by yycwrangler
Thanks John

The battery I was referring to is one of those battery packs with the air compressor built in. I have the 12volts led lights and that's pretty much all it is used for. When we do take off for the day we do sometime take the power pack and use it with our mini blender for smoothies etc.

The power pack can be charged via 12 or 120 volt. So based on that do your recommendations still stand regarding this "Anderson unit"

Cheers
Al

Re: power from jeep to trailer

PostPosted: Thu Apr 04, 2019 10:48 am
by flboy
yycwrangler wrote:Thanks John

The battery I was referring to is one of those battery packs with the air compressor built in. I have the 12volts led lights and that's pretty much all it is used for. When we do take off for the day we do sometime take the power pack and use it with our mini blender for smoothies etc.

The power pack can be charged via 12 or 120 volt. So based on that do your recommendations still stand regarding this "Anderson unit"

Cheers
Al
Al, if that is all the battery pack is, you mosy likely can just plug into your cig lighter up front and avoid the rest. The cig lighter is fused appropriately for the wire they use. You will know straight away if you exceed that. If I am not mistaken, most of those type packs are intended to have the 12v cig lighter charge option?

Sent from my SM-G935P using Tapatalk

Re: power from jeep to trailer

PostPosted: Thu Apr 04, 2019 11:06 am
by yycwrangler
Hi Don

That's what I have done in the past but I'd like to leave it in trailer whenever possible. So if I could put a 12 volt plug in the trailer line and just do the same - plug the battery unit in there to charge the battery pack I'd be in good shape

Re: power from jeep to trailer

PostPosted: Thu Apr 04, 2019 4:06 pm
by John61CT
If that's an old school lead battery at low Ah inside, yes not capable of drawing a high current, probably about the same as running a compressor fridge, say 5-6A tops.

I hate ciggie ports so much, I still say get Anderson plug connections, really should be the standard for reliability.

Do not skimp on wire gauge, keep voltage drop over the distance to a minimum, but a DCDC charger would be overkill compared to just walking the powerpack up to the front to charge.