3-Way Fridge vs AC DC Fridge?

[KenjiFox]

I have both of those monitors myself, great to keep an eye on what's going on.
I also have a Kill-a-watt for spot readings, and my pure sine inverter has an LCD readout too.

I am currently working on running 4/0 gauge cable from my batteries to a distribution bar behind said equipment. Every other 12v wire that will run anything more than my LED lights will be 8 gauge or better. I can't stand for any voltage drop with my solar and generator setup. Gotta be as close to zero drop as I can get.
I don't mind necking it down once it gets where it is going, as it isn't about raw amps for me. Just the resistance of the wire and subsequent voltage drop in distance.
It ends up being important when your charger thinks the voltage is one thing, but it's actually not.

Since you have the power from your vehicle going through a relay you may do well with a booster installed by the batter(y)ies on your trailer. Even 10 gauge wire will drop enough voltage to cut the charging way down from the alternator. Depending on the distance you drive at a time in hours, you could set the booster up to 15v and get a nice equalization charge from it. This will increase the life of your batteries dramatically. Just check the water level. If it's AGM 15.5 volts is better yet.

[redbarron55]

I have the PD-4045 power unit that should take care of the battery when it is on charge.
I have a hankering for a solar system on the roof that would take care of the battery plugged in, driving, or free standing.
Most of my power distribution at 12 volts higher current is #6 with #6 for ground.
Many times people forget that the ground (-) is as important as the + side.
I have a good ground buss fabricated and each circuit has its own supply and return wires.

I put in two sets of terminal srtips and used most of the available fused outputs for individual circuits for pumps, lights, fridge,etc.

[KenjiFox]

Very nice, that looks good. You're doing great with the 6 gauge wire. Certainly, the ground wire is just as important as the positive wire. When doing ohms calculations for loss the distance should always be doubled in order to consider both wires. If I am not mistaken the PD-4045 is the "Mighty Mini" right? That is exactly what I intend to get soon to replace the TERRIBLE 20 amp unit currently in my trailer. That one does do an equalization charge at 14.4 volts for 15 minutes every 21 hours. It's not high enough voltage for the duration IMO, but it's a LOT better than most converters out there when it comes to battery life. Indeed setting up a solar system (always sounds funny) on the roof will be able to better maintain the batteries when driving. Beware the difference between MPPT and PWM, and even more so negative ground vs positive ground. Unfortunately almost ALL cheap PWM solar controllers are positive ground. Renogy has a nice little plug and play unit that is negative ground. No display, but you already have all that sorted out. It's got a button to change the voltage for different batteries. I always run my batteries at the highest voltage the equipment will allow so I select AGM even though I have flooded cells. This means my batteries are in tip top shape when it comes to relative gravity and actual state of charge. The compromise being that I must check the water more often. No big deal. Better to do this with the solar controller than the power converter though, since you want to take advantage of every bit of solar power you can. The panels don't output 24/7 either, so the higher voltage can't harm anything.

The little PWM Renogy that is negative ground is called "Wanderer". It's buried in my closet behind things so I can't look. I'm pretty sure that's it though.
It does very very well for a PWM controller.

[redbarron55]

I think I want two 100 watt panels in series and the an MPPT controller, but I haven't finished thinking or saving on this project yet.
The higher voltage will reduce the voltage drop that you are worried about.
The Bogart guy says that there is little difference in the PWM and MPPT in actual use, but I think that is for panels at 12-15 vols perhaps 18 volts peak power point for the panels.
To reduce the power loss I think the serieed panels with bypass diodes and an MPPT controller will provide more efficiency over time and in different conditions of shade etc.
I have room for two golf cart batteries, but currently only have one group 29 battery installed. It is flooded cell with vent tubes through the wall.

[KenjiFox]

Your thoughts for a setup are absolutely spot on. You will certainly benefit from the MPPT and series setup. With a panel, if you shade a single cell you cut the output severely. Since they are both in series this will happen to the whole thing, but the MPPT will keep on trucking along no matter what hits it, all the way down to one panel. Indeed the series voltage is much better to get the panel power to the charge controller.
I got my golf cart batteries as Sams club. The size is GC2. Get the EGC2 from them if you can. They are the grey cased ones labeled Duracell. The black ones are not as good. For less money you could also get GC2 batts at Costco. Theirs are basically the same as the black Duracell, but you get a lower price and superior return policy.

I have two of the grey EGC2 batts. They are made by East Penn (hence the E) and are extremely high quality.