All my work is done for the day, I made $200 and scored a free rototiller to rehab and resell later. So I have earned my bread for a few days. Then something horrible happened... I started to think.... and scribble and play with a calculator. :help: I have been rethinking the electric usage thing, because I was charging up a car battery and got to wondering how much 12v light I could string the house with, run the light circuit on 12v car batteries and keep them charged with cheap $20 solar car battery chargers. I figured, one battery, one charger, and this would light a string of nice bright parking light type bulbs for a good long while a day, I figured about 6 hrs a day. I wont bore you with that math but I was surprised, that a good sized common car battery will indeed keep a half dozen really bright 12v bulbs lit for 6 hrs before they begin to dim. Halfway good sunshine would recharge the batteries, and presto free evening light for a small investment. I may still do it just for those blackouts or tight months where a spare 5 dollars would make a difference. For now its not worth my investing the cash in itâ¦ but I think I may make ONE circuit and one charger, just to test the working theory. Then I got to thinking, a trickle charger actually puts out more and more reliable steady charge than a cheap solar battery charger panelâ¦ I wondered what does a trickle charger use? So I plugged it into a kill-o-watt meterâ¦ 22 watts draw. Skip the math, thatâs only 5 cents to charge the battery for 24 hours. In fact, one could leave a maintainer charger, running on 22 watts, 24/7, in the circuit, and it would only cost a nickel a day for a long string of maybe 5 lights. If you can cope with dimly lit rooms, its brighter than an oil lamp. Thatâs only $1.50 cents a month, per battery, to keep topped off, maybe less if you donât use the lights that often. A cheap solar charger is $30, thatâs 20 months of charging on the grid! The more I think about it the more it sounds like a good idea.. Lets assume, in my caseâ¦ I need about 20 little 12v bulbs (bright ones, like a back up light) to supply all my dark spots with a happy pool of light. If each room has a switch to turn on and off, I think I can make due with 2 large batteries. (big truck batteries) now to keep a 22 watt maintainer running on each thatâs $3 a month. This will keep me lit up for about 6 hrs every night. If they shut off my power, at least I can have light! And when I drive somewhere, put the battery in the bed of the truck hooked to a splitter and charge it for free while I run around, worst case scenario. At best, I am going to pay the power plant $3 to light my whole house, each month. Its an interesting theory. This leaves me with no hot water, or Tv, or computer. BUT lets think, we can skin that cat two ways; buy a 750 watt inverter at wal mart (about 30 bucks) and bada bing, I can recharge my laptop, my cell phone, and since my Tv and sat receiver takes only 100 watts, even watch a little tv every eve. Hot water, well I got a gas stoveâ¦. Or the wood stove. Iâm not that desperate yet or that gung ho, but itâs a good thing to have already thought over. So for $3 to $5 a month, I could recharge my battery bank, have tv, light and a computer. If I am willing to watch a 4â tv screen, I have a really nice color TV for camping that runs on12v. But I did more figuring and until I get this theory in practice, I had to figure again, the cost of a KWH. They raised mine a whole penny! Now I have to pay total cost, aa whole 7.5 cents a kilowatt hour. What can you do for a measly 7.5 cents? I was surprised actually. Using the trusty kill-o-watt meter, I checked all my stuff, and did some figuresâ¦ based on my cost of power. A shop light fixture on the bulbs says it uses 40wx2= 80 watts, but the meter sez it draws 60 watts. So based on a 60 watt figure I got some interesting numbers to cope with. Skipping the math you can do yourself, you can run a 60 watt shop light for Â½ of a penny an hour, or .11 cents for a 24hr day. You have to admit, this is cheap, considering you could use oil lamps or 12v car batteries. So for about 3 cents, you can run a shop light (60 watts of florescent light) for 8 hours, the same as it costs to pay to charge one battery for 24 hours. I have 7 shop lights total, I use them less than 6 hr a day (night, actually) so my power use, for a whole house full of light comes to a whopping $5.50 a month. For a 6 hr eve of nice bright light, I think thatâs a bargain. Looking back at the math, it will take $3 to $5 a month to maintain a 12v battery system, plugged into the grid, just to keep the same areas lit. assuming you have no solar panels, the battery idea has only one real upside; youll have light and useable 110 power with an inverter, when the power goes off. Use a big deep cycle battery, and a 220v inverter you can pump your well water for a short burst a day, maybe get 30 or so gal before the power drops and the deep cycle needs recharged. For the cost of the inverter, and the big deep cycle battery, this is a great idea to set up on your well system; power blacks out, unplug the well and plug it into the 220 inverterâ¦. Same AC power, the well wont know the differenceâ¦ for a limited time, till your battery weakens. At least, you have way to get water out of the well. Invest in a solar panel and a controller box, and bada bing, charge it the next sunny day. Just for kicks to occupy my head, I figured out that at my present power cost, one watt hour (one watt consumed for one hour) costs .00008 cents. So a 60 watt bulb costs Â½ a penny to run for one hour. A 40 watt bulb costs 1/3 of a penny for one hours light. Broken down, its actually quite a bargain. Until you start to use it for heat. I can heat a 12x24 room with a 1000 watt baseboard heater, and keep it about 60 degreesâ¦ a livable temperature. This works out to $1.80 a day, or $54 a month. WOW thatâs a lot. But $54 will buy 21 gal of kerosene, at a gal a day in that same room I will be cold for 10 days out of a month. So by the numbers, the baseboard, compared to the kerosun heater, is a deal. Kerosun heater = 2.50 a day, 1000 watts of baseboard heat, $1.80 a day. For the cost of the kerosene I could run two 1000 watt heatersâ¦. And have change left over. But I burn wood so the heating is an emergency backup if I run out of wood. No worries there. Good numbers to know. The power hog in the house is the hot water tank. The fridge only consumes $4.00 of power a month. On paper, my Tv and sat uses 100 watts, if I left it on 12 hrs a day (yeah right) thatâs about $4.50 a month. This new laptop uses significantly less power than the tower/monitor setup, drawing over 600 watts. Plugged into the power pack, the laptop uses only 65 wattsâ¦ and actually is a lot more powerful than my old 600 watt system was. The dryer uses only $3 a month (Iâm single, based on 1 load a week). The washing machine with cold water uses .20 a load, with the water pump running to fill it lets say .25 cents a load. Thatâs a dollar a month. I figured out that the power it uses for one load, a deep cycle battery would run about one large load before it was spent. So if a small solar panel had a week to charge it upâ¦. You could, in theory, wash one load of clothes off grid, per week with a deep cycle battery and an inverter. Not a trolling motor battery, you need a big fork lift battery. The last for about 5 yrs, normal use. Depending on the draw, a smaller deep cycle might do the job, actually, depending on the amp hour ratingâ¦. Or you could chain more than one together to up the capacity.