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drizzt321 avatar image
drizzt321 asked

Travel trailer/caravan wiring diagram, please critique

I have a small travel trailer (caravan) which I want to add a 100Ah LiFePO4 12v battery and charging from car while towing, solar, and shore power when I have it, which won't be always but enough I want it around.

Here's the system I'm thinking:

  • Victron SmartSolar 150/45
  • Victron Orion-Tr Smart DC-DC Charger Isolated 12/12-18 (18a, 12v to 12v)
  • Victron BMV-712 Smart monitor
  • Victron Blue Smart charger (110v to 12v, 15a)

Solar will be ground mount, mostly so I can have shade over the trailer and still have solar. It'll probably be a 150 folding "suitcase" solar panel for trips where I don't anticipate a lot of loads and I'll be there a fairly short time (1-5 days). For longer trips, I have a couple of old 235W 56V Vcc house panels in parallel.

I don't particularly expect 110v AC loads, so no inverter, only DC loads.

Short trip expected loads:

  • Basic LED 12v lighting, some LED strips, some LED string lights or the like on the awning outside. If I have everything blasting probably 50-60W, but I rarely expect that, and I'll have interior vs exterior on separate circuits.
  • 12v pump for clean water tank (no model yet picked, I expect ~10a or less, on rarely)
  • Some 12v->USB chargers for phones/tablets and the like
  • Small speakers (guesstimate 40-50W speaker system, maybe less)
  • 12v compressor RV fridge, 50-80W depending on model/size that will fit
  • Possibly my laptop, might just do a 12v->19v boost direct to it
  • Possibly a fan or two

Longer trip additional loads:

  • Evap Cooler for hot dry locations (2-4a for fan and water pump), running for a few hours during the day
  • Charging Li-Ion battery packs for e-bike/lighting (think festivals), 12v balancing charger, up to 30a total load, would only do during day when solar is producing

I plan to mount everything to an appropriate piece of 1/2" plywood, run all the wiring I can, and then put standoffs and a piece of acrylic/plexi over top, which will have a section that's hinged for the disconnect switches (other than the battery, which will be placed right next to it). That will then go into a compartment which does have venting up at the far top to the outside. I might add a small temp sensing fan so if the compartment gets a little warm, it'll turn a small 12v fan on to help provide a little extra airflow.

Solar will be some MC4 pass-through to the outside more or less in the same compartment as the components.

Battery will be in a separate compartment, smaller, with I think 6-8 feet wire run length. Should be close enough for the shut wiring, and I plan to run 4 or 6 awg wiring.

I have cut-off switches on everything so I can isolate them from the battery when not in use, so there won't be any non-useful loads. Also planning on cutting off the battery when parked in storage, although as you'll see the BMV will still be connected since I've ready it's idle draw is in the mA range, so should be fine since it won't be sitting there for too long.

All of the loads will go through a 12v blade fuse box, each fuse sized to the load.

An outstanding question I do have is can I hook the BMV VE.Direct to SmartSolar, it's shown that way in the wiring diagram, but I'm not sure if it does function the way I expect that way.

So, what am I missing, what have I forgotten, what am I doing wrong or could be doing better?

proposed-wiring-for-trailer.png

MPPT Controllersorion-tr smartwiring diagram
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2 Answers
skapicioglu avatar image
skapicioglu answered ·

Hello,


I was wondering if you completed your trailer? If you would like to share news about it, I would be happy to discuss it with you.

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drizzt321 avatar image
drizzt321 answered ·

@skapicioglu so yes, more or less.

I used double pole non-polarized DC breakers for the disconnects, and only fuses are an 80a Class-T at the battery and ATC distribution fuse panel for the distribution to the various lights and such.

I also have a pass-through through a side panel for 12v power outside for some lighting, etc, as well as the MC4 connectors for the ground-mount solar.

I also haven't hooked up the 120v charger permanently, I'm actually considering getting a Phoenix 12/1200 inverter, and either adding a 2nd 100Ah, or getting one of their 270Ah batteries as a replacement instead. Mostly my use has been fully off grid, and the solar/Orion charger from the tow vehicle has been plenty.


When I do add the inverter I'll also hook up the charger full time. However, I'll have to add in a relay or something with the NC position being the charger, and when I flip the inverter on it disconnects the charger and connects the inverter, otherwise it'd lead to some weird charging from the battery and probably all sorts of bad things, with a loop like that.


*sigh* I do dearly wish Victron would have a ~1500-2000W inverter-charger 120v

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