Forum Discussion

Jframpey's avatar
Jframpey
Explorer
Sep 10, 2018

Looking for battery controls

I’m about to take the plunge into solar, lithium batteries and residential fridges... I’m giving up on my dometic N811 fridge, it cools too slow - it keeps shutting down on propane - I’m paranoid about leveling... etc. I have a rear kitchen - fridge is on the back wall - I can’t keep it running on propane while traveling - I think the wind buffeting and suction at the rear of the trailer won’t allow the burner to maintain a useful flame...

So, on to a residential fridge. I do a fair amount of boon-docking therefore I will need big time solar and batteries. I was doubting the feasibility until I saw this website MortonsOnTheMove now I want it.

I’ve located a Tesla battery, the inverter, converter, and I have a source for solar panels - on to the controlling electronics. I’ll need a relay to disconnect the battery for low voltage, high voltage high temp, and low temp. I’ll need fuses or breakers and monitoring electronics... who here wants to help me build this thing?
  • noteven's avatar
    noteven
    Explorer III
    Sep 10, 2018
    lithium should lend itself well to rv engine and small generator charging due to the battery’s fast charge rate. As a backup. So the food doesn’t spoil during 10 cloudy days in the forest...
  • Almot's avatar
    Almot
    Explorer III
    Sep 10, 2018
    800W solar should be able to handle 10-11 cf residential fridge. A while ago inverter fridges looked appealing to me in solar setup - from a distance. Lower startup current etc etc. Then I saw, or, rather, "heard" LG inverter in one company office, it was almost as loud as my 20 year old home fridge. If you can fix the wind issues with your propane unit - do it.

    Buying Li battery from a wrecked car = asking for trouble. You could lose more than just the battery cost.
  • time2roll's avatar
    time2roll
    Nomad
    Sep 10, 2018
    I think Dometic makes a panel to reduce wind buffeting.
    Others have added some furnace filter material to reduce the wind effect.

    Best of luck on the lithium and solar project. It's a bit over my head.
  • Itinerant1's avatar
    Itinerant1
    Explorer
    Sep 10, 2018
    Why don't you try to get in touch with him and see what he's using for management system. Didn't he do you tube videos on the system?
  • Jframpey's avatar
    Jframpey
    Explorer
    Sep 10, 2018
    The battery I’m entertaining is a used Tesla model S pack... 1 of 8 or so used in the car. They come from wrecked low mileage cars 24v, > 5Kwh. I’ll start with 1 and may add another in parallel later. I’m shooting for 800-1000 watts of solar. The link I mentioned above uses a heating blanket if needed to warm the battery from solar if needed. I know I’ll need battery management - there are aftermarket bms’s for these packs.

    Weight is a concern - this pack weighs 55 lbs, vs 6 gc’s weighing 450lbs? And 300ah? @ 12v (50%) (3600wh) vs 4000wh (80%)
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Sep 10, 2018
    Are not there forums specializing in Tesla batteries for off-grid living? I've encountered a few that seem to promote PSW inverter only accessories meaning an RV would need an AC power supply.

    Just for my edification (ignorance) how many cells are in your battery and what is the operating voltage and USABLE ampere hours specs?

    What is the EER rating of your proposed refrigerator? It seems my 24 CF Viking refrigerator space is 20% occupied but the freezer is jam packed along with 2 other giant non-RV chest freezers. I have a busy vacuum sealer machine. But this is at an umbilical house. The upright freezer in the rig (24 volt) is in stasis for now. The Viking if I remember correctly has a 10.9 EER
  • azrving's avatar
    azrving
    Explorer
    Sep 10, 2018
    Can't help you with lithium and I just stick with lead acid so far. If weight is a big issue lith is probably the way to go. Running a resi is no big deal.

    I'm interested and following along so post pics or whatever you can.

    Like I said the residential is not a big deal here's what I'm running.
    Six GC 2, 2000 watt xantrex prowatt, 1000 watts of panels, whirlpool 10.7 resi, satellite, 40 inch LED, 19 inch LED, LED bulbs and the rest of the normal RV stuff. I don't invert to the microwave but do for the toaster at times and a hairdryer.

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