Replacing battery with a power station

MarkL

This may be an old question, but it is a new one to me.    I have just purchased a "Goal Zero YETI PRO 4000 Portable Power Station 3994Wh LiFePo4 Battery".  If a person wanted to replace the Tag battery with a power station, is that relatively easy to do?  I read that someone suggested instead to plug the power station into the shore power.   Is there a way to wire in a switch that in position "A" the trailer would draw from the battery and on position "B" would draw from the power station?   Could a power station rest in a metal box on the hitch or would it need to be inside the trailer?  I even thought that if the microwave were removed, that spot could be used for the power station.  Thanks for any thoughts on this.   I am not an electrician and am trying to understand the big picture.

JamesDow

 
The Goal Zero Yeti PRO 4000 is a nice unit. An A/B switch could be wired in without too much of a problem. I do not know your existing battery type. I would suggest a switch which is commonly found on boats to cycle through multiple batteries. Amazon sells them at a price of around $35. One side could be connected to your station 12V 6mm port or 12V auxiliary power port. 
Resting in a metal box on the tongue hitch could be problematic due to the size of the station (21.4x13.8x14.8) and the additional weight of 115 lbs. I would design/buy a box so you can easily remove the station for flexibility. Security, environmental issues and air flow would be a concern.
I do not know the type and year of your T@G, but possible-maybe. (A fair amount of work)  
As for replacing a microwave for space for you PRO 4000, I think that would require a lot of design and reconstruction. I do not think it would be worth the hassle. 
 
I currently have a LiFePo4 battery and charge it through using my SAE solar port.
As similar to your situation, I can also hook up my self-made power station to the SAE port, which can double my battery capacity. (No switch involved)
If I really wanted to power the one 120-volt T@G item I have (Air Conditioner), I would use my power station inverter and plug the AC directly in, bypassing the T@G converter, which draws around 15-watts in itself. Placement of my power station is only limited by wire length. Can sit on the ground, in the T@G or in the vehicle. When not camping, my power station is normally kept in my house, garage or shed.
 
» Bottom line, I would strive for flexibility. The PRO 4000 can be used for a lot of purposes besides just the T@G.
 
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MarkL

Thank you, thank you.    Very helpful.   Yes, I bought the power station for home use in case of a power outage or emergency.   I am a CPA so I visualized that this purchase cost was part of the home budget and not part of my camping budget (so my camping will benefit from a pretty nice power station).   I do not own a Tag yet but I am looking at a new or used XL.   If I get the 2025 model, I can order it without the microwave which will give me valuable storage in the galley.  That is near the A/C, heater and water heater units in case I need to modify wiring there.   I could put 12 volt outlets for example in the sleeping area from the power station by going through the wooden wall between the kitchen and sleeping area.   I am trying to ask questions to people with experience (such as yourself) whether my ideas have any merit.  YouTube is also very helpful.  

Thinking about the electrical system and trailer options is new to me but as I mentioned I am doing my homework upfront so I can cut down on mistakes later.     - Thanks again, James -