Hello from the Chicago-St Louis neighborhood

[bluegoatwoods]

I have now built two battery/inverter systems of 2000 Watts each. I'll start buying solar panels next. The purpose of the two power stations is mostly kitchen appliances. Of course they'll also power lights in case of power failure on the grid. That's one of the big reasons I've built them.

Another reason is that my wife and I might just choose to do some downsizing. We're already pretty tiny. Our home is modest. But now that the kids have grown and set up on their own, it's more home than we need and wish to maintain. I also don't really want to pay real estate taxes anymore. And I kinda don't want to pay the rather steep costs of being hooked up to the grid before consuming even 1 kw/hr of electricity. I'm not wildly ideological about these things. They just stick in my craw a bit. So it's possible that we could become nomads. Probably not, I suppose. We're aging and time is growing short for that. But if we decide to "bug out" I want to be ready. In fact, if this place............pleaassse NO...............burns down or gets wiped out by a tornado I'm not going to rebuild the conventional way. We'll regard the decision to downsize for real to have been made for us. Plus....we are considering wintering in the desert south-west in the future in order to escape the darned ice and snow. My wife, for that matter, seems to be very enthusiastic for this and might be disappointed if I don't take her there this coming winter. I can still see reasons that it might not be practical. But I'm friendly to the concept and do hope to do it sooner or later. I'd better make it sooner.

So I need off-grid capabilities.

I started with a 2000 W inverter and two standard lead/acid automotive type batteries in parallel. The batteries are on the patio just behind the kitchen. I bought a long and heavy duty set of jumper cables to feed through the wall and floor down to the basement and the inverter went there. This is a 'modified sine wave' inverter and does not seem to power a microwave very well at all. But I've not even yet managed to squeeze very much Wattage out of those batteries and this might have something to do with unsatisfactory microwave oven performance. The cables are certainly stout. Those conductors are nearing a half inch in diameter. The run might be fifteen feet. The connections to the inverter feed are mechanically stout. Though they might not be electrically great. About an inch of exposed cable is hose clamped to a spike of about 5/16 inch diameter. Presumably steel. They were painted. But I wire brushed the paint off. I drove the spikes through a 1 x 2 to keep them from ever touching. Two stout alligator clamps from each pole of the inverter clamp onto the other end of the spike. I add that detail in case anyone can spot some clear flaw which I've overlooked. The microwave made an awful sound when powered up by this and I gave that up immediately. This setup certainly powered lights. And it powered hand drills, random orbital sanders and my modest drill press well enough. Though I could sense that it was all a bit weak. I don't think I ever squeezed more than 1000 W out of it. I should have thought to check that with a clamp meter. I have also used "Kill-A-Watt" type meters at times. Handy gadgets. I especially like the ability to measure total electricity use over a specified time in a circuit with varying loads. Yet they seem to have a very high failure rate. I don't think I want to rely on them in the future if I must regard them as a quickly consumed resource. If I can only get two or three tests out of one before it goes blank or gives nonsense numbers, they they cost too much for their usefulness. My track record so far is not that bad. But it's not a whole lot better. I have ridden on this system for a couple of years now, regarding it as a source of light and small electrical loads in case of grid blackout. But I've kinda neglected to keep a close eye on the batteries. I know I've allowed them to discharge and sit that way. I haven't really paid enough attention. I've only needed it once in this time for an overnight power failure. And it did the job. With this plus a 2000 Watt gasoline generator, I have felt that I'll probably have enough power for a day or so in any other blackouts. Cooking? No. But I've got a few propane camp stoves which would get us by for short periods.

Eventually I bought a 12 V/100 Amp/hr life po4 battery. About a year ago. During this time it has set around only doing small jobs. Occasionally powering a 12 V tire inflator, for instance. But a couple of weeks ago I set it up with the inverter and started playing around with kitchen appliances. It operates a standard drip coffee maker, small air fryer, electric hot plate/burner just fine. The other day I ran a toaster oven at 375 deg on it for an hour. That nearly depleted a full charge. So I guess I gotta regard toaster ovens as being a bit too power hungry. But if I can build the capacity, then it'll find some use. For a few tasks it is just the right thing. This setup has only been in use now for a couple of days. I'm still getting accustomed the "reading" the charger and the charge on the battery with any confidence. And I've found it awkward to get all of our cooking onto this unit. When the main/stove oven plus a few other things are still powered off the grid, it is difficult to test our actual power usage using this rig. But I've got some rough figures together. It looks like a full charge delivers about 3/4 kwhr before undervoltage shuts down the inverter. This would seem to make sense since...........correct me if I'm wrong here, please................a 12v/100 Amhr battery ought to deliver about 1 kw/hr in one cycle. Ideally, that is. Once you take inevitable losses into account, I'd be happy with .9 or even .8 kwhr. .75 seems believable, if only a bit disappointing. But it still could be that I'm merely inaccurate and the real figure is somewhere around 90% or so. That would be fine. So I'm in the testing and "acquainting" stage of this setup. I'm not displeased with it's performance and feel confident that it's manageable.

 

[bluegoatwoods]

It looks like I went over the character limit in my post above. So here's the rest of it:

And then I also bought another inverter a few weeks back. A 48 V, 2000 Watt model. Pure sine wave. This one is meant to power the microwave oven. The reason I chose a 48 Volt model is that I have on hand five 48 V e-bile batteries which, not very long ago, sure seemed to take a full charge and push those bikes about as far as they ever did. We've aged beyond 2 wheel riding in this household. It just beats us up too much and we can't ride seriously enough to justify maintenance and general upkeep. One of the great tragedies of our lives.........and that's only slightly exaggerated...........but we gotta live with it. So why not put them batteries to use? Three of them are 11 Amp/hr and 2 are 14 AH. I figure that's the 12 Volt equivalent of 288 Amp/hr. My mouth watered when I made that calculation. I wasn't going to turn that down. So I went with 48 V.



But I haven't succeeded. One of the batteries did manage to warm a coffee cup full of water in the microwave with, seemingly, enough power. But it also seemed to be exhausted only doing that much. Two others went into low voltage cutoff the very moment I switched on the inverter. I can't test the two last batteries yet since I need to modify their outlets in order to connect electrically with the inverter. I had one clue that not everything was on the up and up. My chargers for these batteries.......three different ones..........did not change from red to green when I expected based on previous use. So I started checking voltages. On all five batteries and on the outputs of all three chargers I got readings of 46 Volts. Okay...this makes sense and it would seem to demonstrate that I was working with under-voltages. But different batteries? And different chargers? All at once? This was odd enough to make me check that multimeter against wall current and other batteries of other voltages. And I got nonsense figures out of them. I repeated it quite a bit since I felt as though something was very weird here. They weren't just a few volts low, and stable, like the e-bike batteries. It was giving me readings all over the map. So I changed the multimeter battery even though the old one was not very old at all. And I still got nonsense readings out of it.



It's kinda frustrating, isn't it? You suspect something is wrong and you start looking for the problem. Then you get a hint that one of your diagnostic tools might be leading you down the garden path. So you start looking into that and the answers you receive are very literally undecipherable. It's an outrage. You're carefully trying to figure out reality and your own tool is hinting that the trouble might be that you've got a hole in the head. I took that multimeter to my old friend, Elon, and had him fling that stupid thing right into the face of the sun. That multi-meter was begging for it!



Then I came back to reality and simply got myself a new multi-meter. It seems to work okay. I might go back one day to those e-bike batteries. Not right now, though. I have higher priorities than that malarkey. And maybe I won't go back. They are lithium ion batts, after all. And maybe they're getting a bit old? And maybe I ought to get them out of my tinder-dry house and into retirement? Lithium ions who may not be trustworthy? Maybe I won't go back. Hate to lose those Amp/hrs, though.



But anyway I simply bought five 12 Volt/20 AH life po4s. I do know better than to connect five in series. The fifth one is merely meant to be a spare, a stand-in, to do other small 12 V tasks. It's doing one of those other tasks right now, as a matter of fact. The main four are hooked up in series and powering that microwave oven just fine. I haven't cooked all that much with it yet. But very preliminary results seem to say that .75 Kw/hr per day will be plenty.



And I feel pretty certain that one day soon I'll build one more 12 V, 100 Amp/hr battery and 2000 Watt inverter setup. This one will be for refrigeration. Could I get by with less than 2000 W? I'm sure I could and I might downsize that just a bit. But I do want robust refrigeration when off the grid. So it'll be powerful and it'll be independent of other electrical tasks.



But before I do that, I'm going to get my first solar panel setup. Maybe 100 Watts, but 200 seems more likely. I won't expect this to power anything more than one of my individual power stations. I'll figure on adding more solar for the other two when I've got a better notion of just how much collecting power I need for a particular station.



My reasoning: If all goes as planned we will be using the solar from spring to fall here in the midwest and then in Arizona during the winter. In my neighborhood it seems that people are advised to count on 4 hours per day of usable sunlight annually. But wintering where there's more clear horizons and skies ought to raise that. On the surface, one might guess that it raises it quite a bit. But maybe not. The days are shorter there, as well. So my off-the-cuff estimate is that my average will be raised by 25%. So this means I ought to count on 5 hours per day annually. A 100 Watt solar panel...........again correct me if I'm wrong, please. That's why I'm writing all of this detail anyway................ought to gain me 600 Watt/hours per day. So I'll need 200 Watts of solar for each of those power stations in order to feel confident about gathering the needed 750 Watt/hrs per day. It's beginning to sound a bit cumbersome. I've been calculating that for some time now. Only recently have I been calculating that maybe it's not quite as cumbersome as I've figured. But I feel pretty uncertain.



So if I need two panels for each power station, then I'll be encumbered with babysitting panels quite a bit. I suppose I'll need to tilt and turn those panels in order to garner just as much energy as possible. I'll need to be mindful of the wiring and put time and effort into protecting that from damage. Or repairing damage. I suppose I'll need to monitor the batteries for full charge in order to swap them for other batteries needed in order to maximize available and usable electricity.



I'll make final decisions on how many panels when I've gathered more experience with them. I do feel that I don't like the idea of six panels. I like the idea of four panels better. This would put a crimp on my energy supply, I daresay. But I'm willing to add more batteries to this mix. In order to store what little extra is collected and a given good day to be used on rainy days. Clearly one extra battery for each power station will be needed. Probably two. Yet I do think I'd rather deal with batteries.........life po4, at any rate...........than with another set of panels, controller, wiring and finicking. But..........man, oh man......that's $1500 in batteries. This is painful.



Still.....I'm enjoying myself and the feeling of independence is good. I'll proceed. With caution? Yeah. But that's okay.