Please help

hello folks, first i feel i should introduce myself, my name is jim, am a bee keeper, age around 50 give or take, am a physicaly challenged with lupus and osteo arthritis guy thats raised his own kids for 25 some years now, am finally going to be moving into the middle of the ozarks onto 8 acres of wooded forrest, no well, no electricity, no powerr lines, so my situation is this, i had some joker try n kill 13 of my bee hives with raid, so i bought some land in south missouri, i am wanting to have some sort of electricty, i have looked into the harber frieght solar kits and have been advised that they arnt much good, i bought an old 1972 camper, it has , was told it has a 750 watt inverter , id like to be able to either use this inverter that allready has the camper wired to it, i will not be using any heat/blower or ac, just want something large enough to run a small 18 amp table saw, will get a 12 volt tv, maybe run a stereo/radio, skill saw, drill, just the basics and like charge laptop. am thinking a two battery system would have plenty of juice, i have been reading and studying but i get lost real easy due to the pain medications including morphine. what id like to find is a shopping list on a smaller 2 -6 volt = 12 volt golf cart battery system . or what i would need to utilize the camper inverter and using solar pannels. i know it be a tall order but hopefully someone can tell me about what they have , or what i need to buy for the camper inverter set up, is just me with 4 chijuajuas, and thankyou much, in advance


  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Please help

    Welcome to the forum, Jim.

    Something large enough to run an 18 Amp table saw is called a big generator. Trust me. There is no sense in building a solar power system for the occasional use of a table saw. You'd end up spending lots of money for a large capacity that you would not need most of the time. I actually tested my 13 Amp table saw and while chewing through wood it was also chewing through 1015 Watts.

    Which brings us to the all important Kill-A-Watt meter. About $30, and very useful. With it you can measure your actual power usage per day on everything you normally plug in and turn on. That will give you some realistic numbers to work with. It's very important to know the peak Watts you would use (everything that might be on at the same time) which determined inverter size and the total Watt hours used daily which is the key to sizing a battery bank. From that you can figure out how much panel you'd need to recharge.

    Things that are big power users and problematic for off-grid include any type of AC induction motor (like the table saw) including refrigeration, water pumps, and air conditioning. Heating is a definite no-no; propane is your friend there. Otherwise its pretty easy to put together a small system that can handle a few lights (CFL or LED for preference) and the miscellaneous stuff that makes life a bit more bearable.

    The golf cart based 12 Volt system is probably a good plan if you're not running an AC 'frige. Otherwise it can be a bit dicey. 225 Amp hours @ 12 Volts is good for right around 1.2 kW hours max per day, which is about the same as my off-grid AC fridge uses.

    Morphine; done that, didn't like it, put up with pain. Between the years and the miles it's a wonder we aren't worse off, eh? :cry:
  • System2System2 Posts: 6,290 admin
    Re: Please help

    oh lets say its a realy super cold day, id be cooped up, hav the wood stove going, a $15 window fan running to circulate air from the wood stove, am board so i have the 12 volt tv running, in facxt i bet they make a 12 volt fan, and lets say i have a dvd/vcr running, recording a program, than while thats recording, i plug in my 15 amp guitar amplifier and then turn on the radio for something to jam to, and while i,m playing with guitar, it gets dark and i turn on a couple 12 volt lights, and trhat would cover every single thing id have running at the same time and is all id have that ran off the solar power.
    cooking, bottle gas and woodstove and open fire pit
    hot water, heated via wood stove in a pot.
    heat, wood stove in a lean-to air circulated via window fan, .
    air conditioning, none, window fan.and a wet shirt.
    power equipment, i have looked at a small less than 200$ genny.
    i also have an inverter that hooks up to truck battery, its a 7 amp inverter and will run my skill saw and drill for building, .
    is why i was thinking buiolding off of the inverter in the camper 750 wat, the fernace and hot water could be disconected from that inverter???so i only would use the electric outlets and 12 v lighting system. no toasters, no coffee makers, no can openers, no microwavem no hair driers, no curling irons, .
    am usualy early to bed and early to rise so there wouldnt be much electrical activity going on other than the fan for circulating air during the dark hours accept in winter when its dark from 5pm till 7 am. there would be say 5 hours with all that listed running, and truthfully would be mindfull of batteries and wasting energy, only one thing on at a time, and will prolly burn beezwax candles for lighting as well.
  • System2System2 Posts: 6,290 admin
    Re: Please help

    i havnt got a fridge or freezer listed, this winter i wont need one and planning to realy go primitive here, do canning and only cook portion sizes, no lewftovers, dogs will eat what i dont , am using powder milk, and non parishable food items, have done this at least two months this summer and am ok with it and eventualy will be canning soups and stews via the wood stove. and wont have any well or water pump for a while, so i basicly need a smaller affordable, not elcheapo equipment, safty is a must here, is why i thought about those 300 dollar kits, but would rather have qualitry, something that i can use for now and possably expand/add more pannels as time and cash permits, the only think else i might add in the future woulds be a small chest freezer and that could be two years from now, and can allways add another system by then cause am wanting to build a secondary caretakers cabin
  • BB.BB. Super Moderators, Administrators Posts: 32,027 admin
    Re: Please help

    I would avoid the $200 generator... Typically, at light loads (200-400 watts), they really suck the fuel down (most non-inverter generators run at 50% fuel flow for 0-50% of rated load).

    The Honda eu1000i/eu2000i (and Yamaha's new models) will use much less fuel to run smaller loads than the cheap genset (work out some fuel usage numbers--many times, the savings in fuel usage will pay for the much more expensive gensets of $700-$900 or so). If you can save 100 gallons of fuel over the life of the genset, you will come out ahead with the better genset.

    Marc/Cariboocoot has >6,000 hours on one of his Honda eu1000i's... And I would expect >2,000 hours with proper oil changes for any of the small Honda (and probably Yamaha) gensets.

    Those are difficult numbers to meet with $200 generators.

    Also, watch the mixing of Watts and Amps between voltages... For example, is the 15 amp amplifier at 12 volts or 120 volts? There is a 10:1 difference in energy usage between the two.

    In general, extreme conservation of electricity usage will be your watch word. A Kill-a-Watt meter is great for 120 VAC loads. One of these is great for measuring DC AH/WH of smaller loads. A Battery Monitor is useful for watching your battery bank capacity. And for general measurements/system debugging, a DC Current Clamp Meter (this $60 DC Clamp+DMM is a great value) will be a lot of help too.

    To build out a smaller solar PV system (lights, computer, recharging batteries, etc.), here is a nice thread with all the details:

    Emergency Power

    Basically a very long thread that starts from the beginning with a few vague requirements through design and assembly for a "portable" solar RE off-grid power box.

    And here is another example by Mike90045 called the Solar Monolith:



    Update pictures/information here.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 32,027 admin
    Re: Please help

    No $300 kit is going to work well for you... See the above thread about emergency power--can work nicely for you with smaller loads.

    For a refrigerator/freezer, you are up into the mid-sized solar system (~1-3.3 kWH per day). No cheap there.

    For a chest freezer conversion, read about one here.

    Chest freezer as a chest refrigerator

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Please help

    Frankly it sounds like a 750 Watt inverter would do it. But you never know; loads can add up surprisingly fast. Your obviously conscious of that and have the right attitude for minimalist living.
    Now let's through a monkey wrench in the works. That inverter in the trailer is probably one of the type euphemistically 9and inaccurately) referred to as "Modified Sine Wave" or MSW for short. Some things do not like that style of waveform, as it isn't a true sine wave. Some of them are just plain square waves for that matter. You might hear noise in your radio, TV, or guitar amplifier. AC motors may not run at all. Battery chargers might malfunction. It's one of the things you should know about before you plug in.

    If you find you do need a bit of refrigeration, look for used RV units. Some of them can be had quite cheaply and have the ability to run off propane/110 VAC/12 VDC. Some of us here have tested refrigerators and found the small AC units aren't very economical in terms of power per cubic inch, but they do use less than the full size units. Just thought I'd mention that if you were to decide you did need refrigeration.

    As for cheap generators, better you should buy a used good one. The cheap ones are that: cheap! They're not easy on fuel, don't produce much power, make a lot of noise, and tend to fail early. Some folks here have bought the "Honeywell" units and complaint #1 is having to pull the rope for 20 minutes to get it to start. My Hondas cost a fortune, but my wife with her broken back can pull-start the 2000 on one tug. You can barely hear it run, and it burns a couple of litres a day on average (Bulk charging in bad weather).
  • System2System2 Posts: 6,290 admin
    Re: Please help

    when i bought the camper, the guy handed me the 1972 paper work, i will go out to the truck here in a bit and look and see if there is any paper work on the camper inverter, might even be a wiring diagram and it may have a place for battery hookups
  • drew4justicedrew4justice Solar Expert Posts: 36
    Re: Please help

    I'd like to reinforce what Cariboocoot said about the modified sine wave (MSW) inverter, which in my opinion should really be called a modified square wave inverter.

    You mentioned that you plan to run an LCD tele? I tried a 24VDC 5000W AIMS MSW inverter (PLENTY of power, right?) and while it might have it's place, it didn't find welcome in my abode.
    For example; ceiling fans sang songs I never heard before.
    ..I have a 55" LED tv and when it's on it's maximum power savings mode, it only consumes about 60w. When driving with the MSW, the TV made a loud buzzing noise which was NOT eminating from the speakers. Perhaps a switching supply? Therefore, I didn't even bother with trying it on my computer.
    ..I ended up canning the MSW and bought an affordable pure sine wave. But I quickly found out that even a cheap ($700) pure sine wave has it's drawbacks as well. For example, it doesn't have the surge capability to turn on my high end stereo.

    You mentioned that you play guitar, etc. so I thought you might be interested in hearing my story. Just don't let your expectations run too high.

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