DIY trailer conversions

[2rocky]

I'm in the process of upgrading things on my 3 horse Gooseneck and I've been devouring youtube content on batteries, lights, wiring and charging systems.

Interested in hearing other folks experiences with adding electrical to vehicles or trailers particularly what Li batteries, inverters solar setups and shore power decisions you made , what you liked and disliked...

 

[WinkB]

I have done it to a couple different trailers. Personally, I like to put a standard 30A 120VAC twist lock connection on the outside of the trailer for shore power. This then easily adapts to any general extension cord or RV cord and makes it easy to use anywhere. I can top off the batteries at home on a small circuit, It I happen to stop at an RV park you are good to go and you can also plug it into a generator.

I also prefer to purchase a charger / inverter in one unit. There are many reputable names out there, just ensure that the one you purchase has the ability to provide the correct battery profile for charging. Some of the lower end ones do not support Li batteries.

With a charge inverter combo you can use your shore power when available and the AC is a pass through, while it is doing that it will also keep your battery charged. Then when you remove AC, it auto defaults back to DC.

I create two output panels one for AC and one for DC. The AC come out of the inverter and then you wire it like your home with each circuit you want.

Directly off the DC, I would create a 12V or 24V volt system to run interior/ exterior lights and such.

The solar tie in is relatively straight forward as well and can be either independent or integrated into your charger. Typically, I have done them as independent.

You should determine what you want to be able to power and for how long. That will aid you in determining how big a system you need to plan for.

 

[Sytes]

I'm in the process of upgrading things on my 3 horse Gooseneck and I've been devouring youtube content on batteries, lights, wiring and charging systems.

Interested in hearing other folks experiences with adding electrical to vehicles or trailers particularly what Li batteries, inverters solar setups and shore power decisions you made , what you liked and disliked...

Progression pics, if you think of it as you continue your conversion.

I dig DIY projects of this sort! Tons to learn and enjoyable to follow along.

 

[2rocky]

If you were doing it in phases what would you do 1st?

my mind set so far is:

1. Battery 12V system (Power Box) - wire lights and charger
2. Inverter for 110 (size?)
3. Shore Power (30 A gives most options)
4. Solar panels and charger

I'm looking to run

1. CPAP (110)
2. overhead interior lights in stock compartment, and Tack room
3. exterior lights to saddle in the dark ( and maneuver at night)
4. Additional reverse light above back door

 

[WinkB]

Take a look at this inverter / charger: https://xantrex.com/library/inverters/pro-series/data-sheet/ I have used a couple of them and they are pretty nice. Not the cheapest, however they perform well. with the 1,000 you can get away with running a small microwave as well. The 1800 will handle the start up of a circular saw without issue.

Do you know what your CPAP draws for power when running or do you have a way of measuring it.

The exterior lights would be 12 V then. The reverse you could hook into the trailer wiring, so you don't have to mess with much there.

I have added exterior drivers' side, passengers' side, front and rear all on different 12V circuits. Each with a unique switch easily accessible depending upon what you are doing you can then pick which ones you want on. I am sure you are well aware you can never have too much light when trying to back a trailer at night.

Take a look at battery price vs performance. You can get a lot of battery in a AGM or comparable vs Li. Li is great if it were not for the cost of entry.

Don't skimp on your power wire from the batteries to the inverter. Try and keep those runs as short as possible and use as large a cable as possible. You want to achieve as small a voltage drop as you can between those two.

 

[Cammy]

I did a 2 horse conversion years ago. No power installed. From my RV experience:

1. 30 amp for shore power
2. 2- 6 volt golf cart batteries. Skip Lithium due to issues with cold
3. Minimum 1000 watt inverter
4. Go as big as you can on solar. Think 400 watts or more
5. spray foam insulation
6. Jakery for CPAP

 

[Arcola]

New lithium battery technology is amazing and it’s only getting better. I have a 460Ah 12V in my camper that lasts at least six times longer than my previous dual golf cart battery setup. Paired with quality converters, inverters and charge controllers and we really have no need for the grid.

Victron is the gold standard for components, though there are other reputable brands as well. Check out the diysolar forum and you’ll find enough rabbit holes to fill 150% of your free time.

I’ll also plant the seed that you should possibly consider 48V over 12V. Much easier cabling and components are typically more affordable. Kinda wish I’d gone 48V over 12 on mine, but 12 seemed easier at the time.

At the end of the day, it depends on how deep you want to go and how much you want to spend.

 

[jason66]

great advice

 

[2rocky]

Progress is slow. I found a DC power cord (12V power outlet) for my CPAP so that can simplify that part.
Considering building a cabinet in the tack room to hold batteries versus mounting them outside under the gooseneck. This should reduce Cold Stress on batteries too. Still thinking LiFePO4 batteries. Wondering about inverter size but it is moving down the Priority list.

Can run LED Lights on 12V. Can Charge Cell phones on USB.

Shopping list is

100Ah LiFePO4 battery
30A shore power outlet
30A/110converter connection (supply side)
Battery monitor https://www.victronenergy.com/battery-monitors/bmv-712-smart
Battery charger
Cables and 12V outlets

 

[Marshfly]

I went LiTime Lithium on my AT Overland camper build. Love it. Internal heating so it can charge no matter what the ambient temp is and bluetooth so I can monitor it from my phone. You won't need the Shunt if you go with this battery.
View attachment IMG_5767.jpeg

 

[2rocky]

Put all the components into an Amazon list and the total came to over $600.

Found a video of a fella who built one in a toolbox. Found the toolbox for $20 off.

I thought this was supposed to be cheaper than buying a Jackary! So I asked Chat GPT

Here’s a side-by-side breakdown to help you decide:

---

DIY Solar System (600W Inverter + 100Ah LiFePO₄)​

Component	Example Product	Est. Price
Battery	12V 100Ah LiFePO₄ (Renogy or similar)	$300
Inverter	600W Pure Sine Wave Inverter (Renogy/Rich Solar)	$100
Charge Controller	Victron SmartSolar MPPT 100/20	$90
Solar Panels	2x 100W (already owned)	$0
Wiring, fuses, connectors	MC4s, cables, ANL fuses, lugs, etc.	$50
Battery monitor (optional)	Victron SmartShunt or similar	$50–100

Total Approx. Cost: $550–$640

---

Comparable Power Station (600W Inverter, 100Ah LiFePO₄)​

Model	Inverter	Battery	Price
Bluetti EB70S	800W PSW	716Wh LiFePO₄	$499
EcoFlow River 2 Pro	800W PSW	768Wh LiFePO₄	$599
Jackery Explorer 500	500W (not LiFePO₄)	518Wh Lithium NMC	$499
ALLPOWERS S700	600W PSW	606Wh LiFePO₄	$399–$499

To match your 100Ah 12V battery (≈1280Wh), you’d need a larger unit:

Model	Inverter	Battery	Price
Bluetti AC180	1800W PSW	1152Wh LiFePO₄	$699–$899
EcoFlow Delta 2	1800W PSW	1024Wh LiFePO₄	$799

 

[2rocky]

I think I'm going to copy the system I saw part for part to learn the process. Then i can upgrade parts as I find my needs exceed the capacity of the unit.
This could lead to a battery backup for my Home Well and electric fence.