converting my van...

Okay, so I have a '97 e150 van that I want to convert into a micro-RV. Currently, I have a 400 watt inverter, which is good for my laptop, external hard drive & cell phones; but I want to install a 3.4 cu. ft. refrigerator/freezer, which will require much more power. Currently, I run the van w/ a 850 CCA battery, but don't want to kill it by trying to run a frig off it. I currently live in this van and will do so for quite some time, yet. My cooking/heating are supplied by propane, so that's not an issue. The following questions are what I need to figure out:

1. Which is best for a battery bank? 6 volt batteries {x8}; 12 volt [x4]; or two 24 volt batteries?

2. Assuming I buy a 3000/6000 watt inverter, how many batteries would be needed in the battery bank, considering the frig would need to be powered 24/7?

3. How do I keep this battery bank charged up, w/o draining my start-up battery?

4. I have no plans to tow a trailer or get a different vehicle, so those type of responses are not welcome; but I'm willing to consider other power ideas that would get me the same results or close to it, yet not cost me my first born to afford it! (I only get $1K/mo. in SSDI!)

5. My original post, several months ago, was unrealistic, so I have scaled it back; although, at some point, I'd like to install a propane water heater and a tiny 12" RV-style oven; which is why I'm looking at the larger inverter--so I don't end up upgrading the inverter again.

I would try reading "Inverters for Dummies"; but I think even that would be too confusing! So, basically, any ideas that could be translated into a really dumb-downed language would be greatly appreciated!!!


  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: converting my van...

    Have you got the refrigerator? Nothing is better than having the actual load and plugging it in through a Kill-A-Watt to see how much power it really consumes during a day.

    You do not need a 3kW or 6kW inverter to run a refrigerator. Nor do you want one, especially at 12 Volts. Really a 2kW sine wave unit will be more than enough.

    Size of inverter is not directly correlated to size of battery bank. The inverter needs to be able to supply the maximum Watts at any given moment. In this case the start of a refrigerator plus a little headroom; 1000 Watts + a bit. The size of the battery bank is a function of how many Watt hours are needed. At this point that is an unknown, but most refrigerators will be around 1kW hour per day (+/-) regardless of cubic capacity (smaller ones tend to be less efficient).

    You're in a van, so that is a big incentive to stick with 12 Volt system so that the van's engine can be used as a back-up generator. Otherwise much will depend on the available sunshine and how much of that you can capture.

    Very basic system:
    Two 220 Amp hour 6 Volt GC2's. At 50% DOD that's about 1kW hour (the bare minimum).
    To recharge that from solar you need 343 Watts of PV minimum and a 30 Amp MPPT type controller.
    15.-2kW sine wave inverter.

    How minimal you go will depend on what happens if the system fails. Start a generator? Start the van engine? Do without?
  • scrubjaysnest
    scrubjaysnest Solar Expert Posts: 175 ✭✭✭
    Re: converting my van...

    I'd search the used RV yards for a working 3 way refrig, ac/propane/dc......the Dc side will typically be 1 amp per volt. In other words at 12 volts the refrig draws 12 amps. Running on propane will save you on inverter size and panels.
  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    Re: converting my van...

    Maby you will find something here interesting.,642.0.html

    He has other post around his living in a van.
  • ZoNiE
    ZoNiE Solar Expert Posts: 100 ✭✭
    Re: converting my van...
    gww1 wrote: »
    Maby you will find something here interesting.,642.0.html

    He has other post around his living in a van.

    Interesting Story. 2 years old. Wonder what he's doing now? Gotta go spend some time at that site. Thanks for the link.
  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    Re: converting my van...

    He now bought a uhaul truck and is decking it out.
  • soylentgreen
    soylentgreen Solar Expert Posts: 111 ✭✭
    Re: converting my van...

    The newer DC fridges (which all seem to use Danfoss compressors) are way more efficient (on 12V) than the 3-way fridges of old. For example, I installed a Vitrifrigo C60i in my Eurovan, and it uses roughly 30 amp-hours per day @ 12V. With a 85W solar panel on the van, this will pretty much run indefinitely.

    Expensive fridges, but super efficient. I believe the C60i is roughly a 2 cubic foot fridge. They make bigger ones.

    You should definitely do the math and see if a better fridge would save you money on batteries & inverters.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: converting my van...

    Vitrifrigo has 2 larger models the C85i and the C115i ( 3.0 and 4.2 cu ft ) page 15...

    And a top freezer/fridge at ~ 10 cu ft

    I had trouble finding some specs...
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Mark_Bolton
    Mark_Bolton Registered Users Posts: 6
    Re: converting my van...

    Same as everyone else said. I looked into this and thought a regular fridge running off an inverter might be a better alternative. Read some websites authored by folks who spend more time studying Politics than Thermodynamics. In the end I went with the crowd and bought an 12v Engels 40l fridge since I was well desperate for a cold beer. The plan is eventually to have 2 of them and a styrofoam esky.

    Use one to keep salad fresh and one to keep frozen goods or any combination. When you have plenty of sun I "store" cold in frozen 4 liter fruit juice bottles and put them in the esky to thaw and keep the salad fresh.

    They are super efficient but you cant take them for granted like a regular fridge. It will take all night to get a load of meat frozen and then you need to open them as infrequently as possible.

    Works brilliantly...