As requested, The issue I was having is my dump trailer battery was only good for four or five heavy lifts, per full charge. The trailer is only a year and a half old, but I've moved thousands of tons with it. Since I am not great about charging the trailer off the house, I set up a solar panel with a voltage regulator. Unfortunately, it will keep a full battery topped off, but after one load, it really doesn't do much. Neither does the tiny wire from the truck through the 7-way plug-there just isn't enough to keep it topped off, even doing thirty minutes each way to/from the quarry. I was on a job, where I was helping a guy who has a dump truck get a pad built in a short time period. I was only able to get two loads before the battery shot craps. After much research, I found even the best batteries only last a year or two of moderate + usage. For the price of a new battery, I was able to set up this 2 AWG system. I used a kit I found on Amazon, but instead of a two-feet lead on jumper cables, I had eyelets put on. I also had to have a couple of feet added to each of the longer runs. The total cost, shipped, was around $125, and arrived in excellent condition. Here's the link, call for special orders and save on sales tax: https://www.amazon.com/dp/B0722J4ZQ...olid=14S458KZ6ATA8&psc=1&ref_=lv_ov_lig_dp_it I didn't want the cables hot, while not connected, so I looked into a solenoid. The issue with a solenoid is the cost for continuous use and the issue of the trailer battery connector would still be hot. To solve both of these issues, I went with resettable and breakable circuit breakers, by each battery. I chose MP, from Waytek. 200 amp with 3/8" studs were around $37, each, shipped. I started with some cheaper ones, from Amazon, but sent them back due to coming with 1/4" studs. The MP are made in USA and substantially heavier built than the cheaper Chinese ones. Here's a side by side, of the circuit breakers: I also order twelve inch 2 AWG cables to go from each battery to the other end of the circuit breaker. From the battery in the truck: Ignore all the electric tape. It's temporary, until I decide if I'm going to put another battery in the truck. The cables are then routed through the frame and to the rear, by the hitch receiver mount, which is integrated into the flatbed. Right now, the cables are not in a sleeve. This will be changed, when the weather gets nicer. I found some tubing that is flexible enough to work, but rigid enough to really protect the cabling. It's also very inexpensive, but not available locally. It comes in ten foot sticks and I will get some next time I go to the big(ger) city. At the rear of the truck, I have the cable zip tied a few places. The end is just tucked up between the mount and the bed. Even if it comes out of its hole, it sits over a foot above the ground. Here's how it looks, connected to the trailer. Enough slack to make corners, but not get in the way. These are the connectors close up. They are Anderson 175A SMH and they are very sturdy, so far: Then, after being connected, the 2 AWG goes into the trailer toolbox, through the factory grommet for the trailer wiring. The positive side goes to another circuit breaker, then to the battery. The negative side goes straight to the negative battery terminal. This breaker can also be thrown, so the plug will not be hot. This tape job will likely stay as the trailer stuff gets bounced around much worse than the truck stuff. The small wires coming off the front of the battery are to the solar panel. I bought nice wires with plugs on those, too. To compete this project, I set up my truck with a high idle. Even gas Ford Super Duty trucks come with an option for high idle. I have to be in park, set the parking brake, tap the service brake, then activate the first switch. This switch kicks the idle from 600 to around 900 RPM's. Once it's up to 900ish, I activate a second switch which is routed through a potentiometer. I can spin the pot to change the high idle from 900 to around 2,400 RPM's. This is in case I find the need to keep the 2 AWG connected, while running the pump or if I have a winch connected (the winch is a Warn 9000 and draws a lot of juice). How well does it work? No idea. Since I got all this done, I haven't had any jobs.