from Keeping the Grid Up, part 4
Some people have been discussing a way to capture some power in the event that we have rolling brown outs but not complete loss of the power.
DennisC posted some helpful ideas which I will copy here. I am interested in trying this and thought others might have some ideas too; we can capture them here to help others.
From DennisC — who also refers us to Eccles for more information! (-:
First this is just a “small system” just for a few lights, a computer, radio, that kind of thing. It is not for refrigerators, electric heaters, power tools and the big current type of items. Just a Quick and dirty start.
I will give the Wal-Mart type of items since that is what most people have access to. However, I would just shop locally and see what “deals” I may find. (For example, you sometimes find good deals on inverters in pawnshops).
The key thing is the battery. You will want to be sure it is a “deep cycle” battery. The kinds they use in golf carts or marine electric trolling motors. Auto batteries will “die” after a few dozen deep power drains. You can start with one battery and then connect more in series with them. (I will leave it to Eccles to suggest any optional protective circuits). Wal-Mart has marine batteries. I would just start with which ever one you can afford. The larger the amp-hour rating, the more “power” (OK energy for purists) you can store.
The inverter should be rated for about twice the load you expect to be using. Wal-Mart has a Whistler 800-Watt Power Inverter for about $57. It can put out 800 watts continuous or 1600 peak. You should be able to use it for 500 W with no problems.
For the charger, just use a regular automotive 12V battery charger. The kinds that are “automatic” are the best. They are designed not to over “cook” your battery and you can just leave them on all the time (in case you don’t know when the power will be on). I use the 6-amp Black and Decker “smart battery charger”.
All you do is connect the charger to the battery (red to positive and so on), connect the inverter to the battery (red to positive- see its directions), then plug in the charger. You should now have a back up power system. (I am guess, at a price around 120 to $200).
You now can plug in a few items into the inverter and have power even when the there are “rotating blackouts”. If you want to get fancy you can add a small solar array (like from Real Goods) where the charger is. Or you can even run a jumper cable from a running car to the battery to charge it. (But do your homework first on that).
One of the most disappointing aspects of arranging for backup power is how expensive it can be to have even a limited amount of power available when your regular electric service is interrupted. What Dennis C has described will work when the normal electric service is intermittent. To have some power stored for long term outages, the best solutions are to store energy in your battery from solar panels or a wind powered generator. This is where you can put a real drain on your bank account. As I stated on the “Grid 4″ thread, all of this has been discussed in great detail on the “Solar etc.” threads.
To make the most of the power you have stored in a deep-cycle battery, power as many things as possible with 12V DC. I bought DC cords for my laptops and also purchased a battery charger (AA, AAA, D, etc.)that can run on DC. I have rechargeable lanterns and a small TV that can also use DC power directly. Use an inverter to convert your DC power to AC only when necessary. There are losses involved in the conversion, plus the inverter draws power to operate at “idle”. The two combined can pull your battery voltage down in short order.
Thanks HillBilly Bill!
I have briefly followed the “solar etc.” thread but pretty much everything there is outside my pocketbook.
What Dennis C. suggested seemed at least do-able.
Average Concerned Mom – at 08:20 You can start with one battery and then connect more in series with them.
I submit that you will have more success by connecting those batteries in parallel rather than in series, unless you have an inverter designed to operate on 24 or 36 volts.
Average Concerned Mom – at 08:38
I wholeheartedly agree with you. For normal outages, and intermittent service, the batterycharger→battery→inverter setup works well. Just remember that what you can power is limited. Also, a small battery charger is all you need for all but the most dire situations.
just need to power my breadmachine! (-:
Oh, and maybe the video player.
And not at the same time.
But seriously — I’m realizing my idea now is a lot like what everyone else (I mean TPTB) seems to be doing —planning for what you can reasonably afford, not for what you think will be needed. )-:
Sorry for thread drift.
if you want to extend the idea for times with no grid power, you just add a solar pannel instead of the battery charge. Real Goods has a small 15 watt pannel (though it took me 2 months to get it delivered). The solar pannels run up the cost a lot. But you can get small solar pannels for keeping car batteries charged from a lot of places. They won’t give you a lot of power, but even a single small light in the darkness can work wonders (almost a mystic saying) and it would let you use a radio, a small “RV TV” or DVD player or other small item.
If you have gas for the car, you can jump charge the battery if needed. Fancy people can add one of the quiet Honda generator as a charger. But again, just a simple battery charger will do a lot.
Better to charge a single small battery than to curse the darkness.
Just wondering … how does one calculate the amount of time a battery will provide sufficient juice to an inverter to run an 8.5 amp (110 volt)device (water pump)? My plan is to plug in our water pump to an inverter connected to 1 or 2 deep cycle batteries. Then as power is available …. or more likely I run my generator for a period of time each day, I can recharge the battery(s).
Average Concerned Mom – at 08:59
Interestingly enough, the main reason I invested in my alternative energy system was mainly to power my Bread Machine. I couldn’t justify running a generator for 3 hours just to bake a loaf of bread, and using the Bread Machine was the least energy consuming way of baking bread with the exception of doing it somehow over an open wood fire.
Be advised that a modified sine wave inverter can cause electronic devices that run on a timer, such as a Bread Machine, to “count” time incorrectly. I would advise practice beforehand to see if you need to make adjustments in the normal settings. Also, the last 30 minutes of the cycle of my breadmaker, when it is actually baking the bread, REALLY draws a lot of power. A single 12V deep cycle battery may be discharged below an acceptable level (50%) so you should consider purchasing more than one battery and connecting them in paralell. I used ready-made cables from Advance Auto and have had good results with them.
RBA – at 09:11 to estimate the “power” needed or you can get out
The thing is that energy is conservered. You multiple the time time the power (watts times hours). About 80% or so of what you put in you can get out (that number depends on a lot of things). If you are using a generator or charger you can mutiple the watts (use the amps on your charger multiplied by 12 volts to get the watts or just the wattage from a generator) by the time it is on. That gives you how many watt hours you have stored.
How much you get out is the same. Just look at the wattage your load needs and the time you run it.
Hope that is clear. energey (watts multipled by time) in and energy out (watts multiplied by time). About 80 % or so of what you put in you can get out (some systems are better some or not).
DennisC – at 09:24 Thanks so much for the info.
So am I correct in the following calculation … if I have two deep cell batteries wired together providing a combined amperage of 600amps, I should be able to run a 120v, 8.5 amp pump motor (1020 watts) around 7.06 hours. (I recognize that I would not want to run the batteries down that much … but theoretically there would be enough amps)
I got this by using the following formulas:
Does that sound right?
RBA – at 19:21
Eccles or Will would be the guys to give you exact calculations, but I see some errors in your thinking. First off, I’m sure your pump will take a much greater amount of power to get going (surge) than the running amperage you are using. Next, there are losses in converting DC to AC and also in the resistance of your wiring. Finally, a deep cycle battery should never be discharged past the 50% level, and you are better off staying on the high side of 70%.
My suggestion, run the pump for a shorter length of time with your genny and at the same time charge up your battery bank for other tasks that are less energy intensive.
Just for a comparison, I have a battery bank of three 115Ah deep cycle batteries. If I run my Bread Machine through a normal cycle that takes 3 hours, my battery bank goes down to about 70%. That Bread Machine only really pulls a lot of power during the last 30 minutes and then the max is 500 watts for about 30 seconds to heat up the element every couple of minutes.
To quote my mentor, the Great Professor Eccles:
“The goes-outa is a lot quicker than the goes-inta”.
Yes, that is a lot of current so it will really heat up the wires and you will need very heavy guage wire. I don’t know what your system is exactly, but if your pump is above ground you may want to get a 12V pump to keep the amps down and the inverter cost down. I use a Real Goods 12V pump that is designed for solar operation. Again, the system I was talking about was just a simple low wattage thing for just a light load. Pumps and motors are a different problem. They take a LOT of current at start up (they have to store energy in their magnetic fields to get started).
Question… we have one deep-cycle battery (amp hours unknown), purchased at Walmart (I think) a few years ago. We’ve been using it at our cabin on a fairly regular basis. We’re thinking of adding a second deep-cycle battery connected in parallel. I’ve read that if you’re using more than one battery that they should be purchased at the same time, charged the same, etc. Is this really a big deal, or something that I don’t need to worry about too much? (PS- The battery is used only to run dc lights, a dc ceiling fan, and a small on-demand 12vdc water pump).
Kim – at 22:18
Yes, it really does matter. My advice, bite the bullet and buy two batteries that are exactly the same. Charge them both completely before connecting them in paralell with heavy guage cables. Save the other battery for an emergency backup. A small solar panel would keep it trickle charged and ready to go. Nothing about alternative power is cheap unfortunately.
Thanks HB for the quick response. Now here’s another (maybe dumb) question… We generally don’t leave much at the cabin for fear it will either get stolen or burned up in a forest fire. The battery is one of the things we lug back and forth. If we left our old “backup” battery inside the cabin on a trickle charger over the winter, would that cause problems? It will definitely get way below freezing in the cabin, but I think we could set the battery and trickle charger where it would get at least some direct sunlight thru an upper window. We’d charge the battery with AC from the generator before we left, but I’m wondering if freezing will do bad things to the battery.
Freezing doesn’t ruin a charged battery (the acid created by a charged battery prevents it), although I suppose it may not be ideal storage conditions. If it can get some trickle charge, even ocasionally and started out in a charged state, it shouldn’t lose enough charge to freeze. I have left charged batteries on unheated garage shelves (and in cars) for months (with no charging at all), and they seemed fine. Some solar trickle charge would make it last a winter well, but don’t expect too many years out of a battery, they tend to go through that last half quicker than the first half of power capability. If unattended, you may want charger control to prevent overchargingif you hook the solar panel straight to the battery (unless someone here knows the solar panel won’t overcharge - I suppose a small solar panel maximum power output IS a trickle charge!)
Do note inverters, at least cheap ones, draw up to 1 amp whether or not you plug anything into the inverter to use it! Turn the inverter off or disconnect it from the batteries when you are not doing anything with the power.
Oh, lordy, this is all too complicated. (-: No wonder I am wigging lately. There is just too much to learn. No one thing is hard but all together it is overwhelming. Especially if you haven’t got any money!
I’ve changed my mind (for anyone who cares) about the bread machine. Power goes out, we’re eating gruel. Recipe: 1 cup flour. Add 1/2 liquid. (milk. water. heck, beer.) Mix and eat. See, nothing to learn. (-:
Fiddlerdave, thanks for the warning on the inverter, but our setup doesn’t use one as everything we use the battery power for is DC. Whilst we probably should have a fuse in there somewhere, the lights, fan and pump all run on DC and are all direct wired (DH put these “ring” type connectors on the ends of each Romex cable, so we just unscrew the wing nuts on the battery terminal, drop the cables on, and screw down) to the battery with 12 ga Romex (the entire cabin is 16 x 20, so no long wiring runs!). Each appliance has it’s own on/off switch so there (should be) no battery drain when things aren’t in use.
Sounds like it may not be worth the hassle (and worry) to leave the *backup* battery at the cabin. Think we’ll just keep it here at home and only lug the 2 new batteries back and forth.
Kim – at 10:32
I would not leave the battery in the cabin. While it may not freeze, the temperature extremes would definitely shorten the battery life.
HillBilly Bill – at 22:06 DennisC – at 22:14
Thanks so much for the posts … they were very helpful. After reading your comments and doing some online research I found a highend 12v marine pump that will work for our emergency needs.
Finally sitting down and learning the different electrical formulas was something I have been meaning to do for sometime.
Thanks again!
ACM - lol! I’m right there with you. Those solar/power threads of Eccles make my eyes glaze over. I’ve learned so much thanks to Eccles, HBB and all - they’ve done a great job explaining it to electricity novices like myself as well as those far more sophisticated.
If you want to read it all in one place, I have a section in my book free here online that walks through it step by step.
LauraB
I just wish I could barter with someone. Like, I’ll can some meatballs for you if you’ll hook up a marine battery-inverter-transformer-decoder-ring-photon-torpedo thingy for me. Wish I knew someone around here who wante dthat kind of a trade… (-:
Average Concerned Mom – at 20:42
ROTFLMAO
That is so funny, but I know how you feel. I give massages and can write awesome sales letters for barter!
Thanks everyone! I actually sat down and learned a lot of stuff last night. My wigging out comments notwithstanding. I can do this. Connect red to to red, I can do that.
As with (nearly) all of our preps, having some alternative means of power is a good thing for “regular” emergencies as well. Our power went off in the middle of the night recently and as I gleefully turned on some of my emergency lighting gizmos, DW said “I sure hope we can make coffee in the morning.”
I told her not to worry, I had it covered. I was actually disappointed when the power came back on before we got up.
HBB et al.,
Thanks for all the information — very useful.
I have a quick setup question for you: How do I get power from the battery/inverter to fixtures etc. that are far away? If I have a battery bank in the basement, do you recommend running a heavy duty extension cord from the inverter up to the second floor and then tier off that (i.e., smaller extension cords to different rooms)?
Similarly, how would I get a trickle charge from a solar array mounted on the roof to a battery bank in the basement?
Thanks again.
My 9 year old daughter and I tried an experiment a couple of years ago for her science project. We bought a trickle charger for about $10, and walked through the alleys in our neighborhood till we found a car battery. (no, it wasn’t still in someone’s car!) She towed it home in the wagon, and we plugged it in in the garage. About a week later, we twisted wires together (red to red, black to black) and had lights. We got about 24 hours out of a 12 volt fluorescent lantern. I’d bet we’d get a week out of LEDs.
S. Arlington – at 08:54
These are situations that I have dealt with also. The main rule is to keep your 12V wiring as robust and short as possible between the battery bank and the inverter. Once you have AC flowing from your inverter, you can use the setup you are talking about with no problem. I have a 12 guage extension cord running from my inverter in the basement to the kitchen where I will need the power the most.
Your second question is one I struggled with. The longer your run of wiring from the solar panels to your charge controler/battery bank, the more energy you will lose due to the resistance in the wiring. If you can relocate the battery bank closer to the panels, that would be great, but I understand if you can’t. My battery bank really has to be in the basement workroom also. I ran 8 guage wiring down an unused chimmney and across the basement for a total length of 55ft. to get to my setup. Yes, it was expensive buying the wire, and no it wasn’t any fun running it. I suggest you use the same guage I did unless your run of wiring is significantly shorter. You could possibly double up on 12 guage wire if you have some already on hand.
Hillbilly Bill – at 08:26 “ I was actually disappointed when the power came back on before we got up.”
That cracks me up!!! (been there)
S. Arlington – at 08:54 “How do I get power from the battery/inverter to fixtures etc. that are far away?”
I think Eccles and HB are working on a wireless, power recycling system. Should be out soon!
You do Professor Eccles a disservice by mentioning my name in the same sentence as his. Countless questions and emails have been answered by my mentor so that I could acchieve this lowly level of proficency.
Sounds like it was all for good cause. Now I can be gone for a few days on other issues, and come back to find that the novices are in good hands, and have not blown themselves up, or anything.
(By the way, I like meatballs, but they made me promise not to install any more photon torpedo launchers. I think it’s a Gun control issue or something).
Eccles – at 12:07
Glad to have you back PGFME!
Eccles – at 12:07
Glad to see you are around. No photon torpedo launchers here but since you might get a kick out of it: I am trying to make an infrasound non-lethal weapon deterrent system. If nothing else it might keep the ducks of the pond.
DennisC - You need top be a little careful with such a system. Some frequencies can be very damaging. Be sure you know what frequencies you want to operate on, have a good stable frequency reference, and measure the waveforms BEFORE you transduce it. OK?
Yikes- and “non-lethal” doesn’t mean “non-permanent damage”. article
Spoke too soon, Eccles? ;-) “Now I can be gone for a few days on other issues, and come back to find that the novices are”…
Eccles – at 12:38
Yes, I am working around 5 to 20Hz (fast rise time) and yes I have a Hameg spectrum anayliser and a Clark Hess power meter. (and this is an easy range for scopes) The transducers are will be placed along my outer perimeter and away from the house. It will be my first line of defense and mostly in a warning mode. I already have my second layer in place- motion detector controled sprinkler system (they sell them under the name scarecrows) but I can add formic acit to the water system there. Those are all non- lethal but it should give an intruder pause for reflection.
OOPs I am letting the thread drift- excuss me, just thought you might enjoy what I was up to.
crfullmoon – at 12:45 The article is about high intensity directed weapons. The directional items are at higher frequencies and most are ultrasound items since they require short wavelengths. The item I am constructing is more for harassing an interloper and will be working at around 100 watts of acoustical power (think those loud car stereos). I am working on the very long wavelength that is not directional though you can get standing waves if you work at it for say a gate area. I figure a low level warning should suffice for most “visitors” and I hope to be able to superimpose an audible warning as well. But I need to sign off this thread since I am drifting. If you want to talk more we can open a new thread.
this extraordinary situation planning has some paralles with ordinary lifes policy on energy. Norway a country with plentifull of natural resourses like hydropower has been organized to completly run everthing on electricity. Now when we are conected to the European comon market also with eletric power, the reality suddenly kicks in. Using electricity for heating is not a very good idea, its should be reserved for light, machines and electronics. It will take years before all households have an alterntive way of heathing, And we learn the hard way by paying our blood in electric bills.
Now for emergency and camping this is similar, running a oven on baterys dont make much sence… Propane for those who want to invest, Or small camping stoves for multifuel like parafin/ kerosene /lamp oil (whatever your preferd pricerange) will do fine for baking with one of these:
Urdar, what alternative heating methods are being explored in Norway? Solar would be difficult at such high latitudes, so I’m assuming ground source heat pumps, higher insulation, and biofuels are the likely alternatives.
I recommend this if you can afford it; LSER
Will – at 07:24
coincidentally my link is shows it in the Netherlands.
Backup power for a small town: