# Battery-power explained



## NaeKid (Oct 17, 2008)

I have been looking at / researching what I can about batteries, solar-systems, wind-generators, wiring, etc for quite a few years now. I have been using a calculator to try to figure out what works in theory vs. what works in reality.

This morning I found a quote that explains very well what I have learned over the years:



> Amps are how many electrons flow past a certain point per second. Volts is a measure of how much force that each electron is under. Think of water in a hose. A gallon a minute (think amps) just dribbles out if it is under low pressure (think low voltage). But if you restrict the end of the hose, letting the pressure build up, the water can have more power (like watts), even though it is still only one gallon a minute. In fact the power can grow enormous as the pressure builds, to the point that a water knife can cut a sheet of glass. In the same manner as the voltage is increased a small amount of current can turn into a lot of watts.


For a solar-panel to "push" power into a battery, it must be able to do so faster than what the draw out of the battery is. My 80-watt solar panel on my camper pushes (calculated) 5-amp of power into the batteries at high-noon. For me to replace my 80-watt panel with a 120-watt panel, I would only gain approx. 3-amp of power (about 8-amp calculated). To put on a pair of 120-watt panels would give me about 16-amp (calculated) worth of power into the batteries.

Now, if I run all the lights / pump / furnace in the camper at the same time, the power-draw exceeds the maximum amount of power that the panel can provide, so, the power must come from the batteries, draining the power from them (think of the battery as a water-reservoir). If the solar-panel doesn't have enough time to refill the battery before the end of day, the amount of available power leaving me with less than a full "reservoir" of available power.

For a short night in the summer where the power-draw is low, I should have more than enough power in the batteries with my current setup. For a long night in the winter (and a very short charging day-time) the power-draw could bring the batteries down to "dead" state where there isn't enough available voltage to run the camper.

To compensate for that, I could add even more batteries to the mix for more "reservoir" available but I would still need to add more solar-panels to make sure that there is sufficient "flow" into the batteries. It is a never ending cycle of adding more till you reach a point of "more than enough" - and at that point you can stop spending money on wiring, panels and batteries and start living again.

*How do you decide when it is enough?*

Trial - trial - trial. Live it and you will figure out fairly quickly what is enough. But, sometimes that answer isn't good enough. Sometimes hard-numbers are needed and an electrical-engineer might need to be hired to really work your system over to locate areas of phantom power draws. If you cannot afford to hire one, see about talking to some teachers / students at the local college to see if they could help you out with the math as part of a "practicle" portion of the class.

*Closing-thoughts*

We have members here who are living off of solar-panels and batteries and they have shared their experience with all of us. If you are seriously considering making your own power, search the forum and answers will slowly appear.

Good LUCK!!


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## nj_m715 (Oct 31, 2008)

The best way to save when using solar is to cut usage as much as you can. Running energy star appliances, using cf or led bulbs and stop phantom loads etc. A kill-a-watt will tell you how much any item is using. Needing less solar is the cheapest way to use solar, if I'm explaining myself well enough.


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## mosquitomountainman (Jan 25, 2010)

nj_m715 said:


> The best way to save when using solar is to cut usage as much as you can. Running energy star appliances, using cf or led bulbs and stop phantom loads etc. A kill-a-watt will tell you how much any item is using. Needing less solar is the cheapest way to use solar, if I'm explaining myself well enough.


Very, very good point!!!! The biggest mistake we see is people trying to live off-grid the same way as they did on the grid. It won't work unless you have lots of money to invest. It's much more economical to cut your needs than to expand your soalr power system.


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## mosquitomountainman (Jan 25, 2010)

NaeKid said:


> *... How do you decide when it is enough? ... *


Generally, if by sundown your batteries are not fully charged you need to add more generating capacity (more or larger solar larger panels) or reduce daytime usage.

If by morning your batteries are drawn down to the minimum you need to add more batteries or reduce your night-time usage.

Use power strips everywhere and shut them off when you aren't using the appliance hooked to them. Televisions, computers, microwave ovens and many other appliances have circuitry that draws power even when the appliance is turned off.

Learn to use less power on overcast days.

There's an article on the web that's somewhat dated now but has some good information for those contemplating an off-grid life. The title is "paring down for off-grid living." Run a search and it should turn up. I believe it was first published in Backwoods Home magazine.


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## Sonnyjim (Sep 17, 2009)

mosquitomountainman said:


> There's an article on the web that's somewhat dated now but has some good information for those contemplating an off-grid life. The title is "paring down for off-grid living." Run a search and it should turn up. I believe it was first published in Backwoods Home magazine.


Paring down for off-grid living by Steven Gregersen Issue #93

Just read it, great article.


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## The_Blob (Dec 24, 2008)

mosquitomountainman said:


> Generally, if by sundown your batteries are not fully charged you need to add more generating capacity (more or larger solar larger panels) or reduce daytime usage.
> 
> If by morning your batteries are drawn down to the minimum you need to add more batteries or reduce your night-time usage.
> 
> ...


and once you're dialed in... *add 30%* 

once thing many first time solar panel owners forget... keep them accessible enough to keep clean easily! IMO that means only put them on the roof if you *have* to


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## NaeKid (Oct 17, 2008)

Sonnyjim said:


> Paring down for off-grid living by Steven Gregersen Issue #93
> 
> Just read it, great article.


That guy sounds like he knows what he's doing ... would love to meet him and chat with him in person some day! :beercheer:



The_Blob said:


> and once you're dialed in... *add 30%*
> 
> once thing many first time solar panel owners forget... keep them accessible enough to keep clean easily! IMO that means only put them on the roof if you *have* to


The best reason to put panels on the roof is so that they are relatively protected from certain elements that can do them harm, but, they become a "fixed" asset and it is difficult to adjust them due to the angle of the sun through-out the year. A combination of fixed panels and adjustable panels might just be the better choice to go with.

IE: If you are running independant power circuits for charging batteries that are dedicated to certain sections of the home, you could use smaller fixed-mounted panels to keep those batteries topped-up. Main living areas such as living-room / kitchen are primary zones of the house, so you would want the best panels / batteries dedicated there. For other zones of the house where you visit for short amounts of time (like a bedroom or bathroom) a small battery and small panel could keep that area safely powered all year long.


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## Tirediron (Jul 12, 2010)

The other thing to remember is that Lead acid batteries involve the transfer of material every charge/discharge cycle and have a life span, factor this in when planning a system , also bear in mind that one bad battery can wreck the others.


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## labotomi (Feb 14, 2010)

NaeKid said:


> I have been looking at / researching what I can about batteries, solar-systems, wind-generators, wiring, etc for quite a few years now. I have been using a calculator to try to figure out what works in theory vs. what works in reality.
> 
> This morning I found a quote that explains very well what I have learned over the years:
> 
> ...


Sorry to nitpick...If this works for you then great, but it is flawed in it's explanation and actually it's logic.

Increasing the resistance in a circuit does not increase the voltage, so increasing the resistance will decrease the flow and therefore reduce power.

A 40W light bulb has more resistance than a 100W light bulb (and 100W is definitely more than 40W)

Power in a simple DC circuit is equal to (current squared*resistance)
if resistance is doubled the current is halved and since it's effect is squared it has more of an effect therefore actual power is reduced.


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## labotomi (Feb 14, 2010)

Tirediron said:


> The other thing to remember is that Lead acid batteries involve the transfer of material every charge/discharge cycle and have a life span, factor this in when planning a system , also bear in mind that one bad battery can wreck the others.


This is true, but a properly maintained battery can last for quite a long time. We had a very large battery on submarines. 128 cells, each over 1100 lbs dry with a 11000 amp hour capacity (3 hour rate). I was involved in one battery change out and it was just due to scheduling not because of any problems. The battery was over 15 years old and not a single cell had gone bad in that time. We charged it weekly and discharged it very slowly the rest of the time (trickle discharge). Once a month we discharged it rapidly and then performed an equalizing (conditioning) charge.

If you don't abuse the battery it will last a long time. If it's neglected (over discharged, overcharged, never conditioned, too hot/cold, electrolyte levels not maintained or improper acid concentrations) it will fail prematurely. The electrolyte concentration shouldn't change if the level is maintained. Just remember that *any* charge or discharge causes hydrolysis turning the water into hydrogen and oxygen. this causes the level to go down so you routinely should monitor the level and add water to maintain level and thus acid concentration.


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## The_Blob (Dec 24, 2008)

a good Ohm's Law chart










you should be able to do any DC calculations you need with it

AC only takes a little more math, but not much 

Ohm's Law for AC

is a simple calculator


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## labotomi (Feb 14, 2010)

The_Blob said:


> AC only takes a little more math, but not much
> 
> Ohm's Law for AC
> 
> is a simple calculator


LOL...It may seem simple to you *now*, but it looks intimidating to those who haven't studied the subject. How many here would have an idea of what CosΘ represents or even that voltage and current aren't necessarily in phase with each other?


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## nj_m715 (Oct 31, 2008)

http://www.preparedsociety.com/forum/f26/how-many-posters-does-take-change-litebulb-5010/

9th line down? eep:

all in good fun bro.


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## The_Blob (Dec 24, 2008)

labotomi said:


> LOL...It may seem simple to you *now*, but it looks intimidating to those who haven't studied the subject. How many here would have an idea of what CosΘ represents or even that voltage and current aren't necessarily in phase with each other?


luckily, I've *always* been an 'engineering nerd'... ever since I found a Radio Shack 200-in-1 electronics hobby set at the flea market for $1, I was *hooked*


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## labotomi (Feb 14, 2010)

nj_m715 said:


> http://www.preparedsociety.com/forum/f26/how-many-posters-does-take-change-litebulb-5010/
> 
> 9th line down? eep:
> 
> all in good fun bro.


:beercheer:
That was my point


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## dawnwinds58 (Jul 12, 2010)

Could you please relate the patterns of "trickle discharge, and conditioning" as it applies to the use of deep-cycle batteries in an energy array? 

We're aimed more at wind being the primary source and solar for selective potions of the load here. 

Let some dummy set off a bomb or one volcano have a "hissy fit" and sunlight is reduced which in turn reduces your ability to produce enough energy, and reduces daylight for plant growth. I figured on having a backup plan. No matter how hot, or cold, or dark, there is always wind being produced somewhere due to temperature fluctuation and base topography. We're in a wind funnel here between lakes and rivers which gives a higher than average wind speed for this area.


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## CulexPipiens (Nov 17, 2010)

Take a look at

DIY Solar Panel help - tutorials, calculators and design tools for solar power

and specifically the "Solar Simulator" and "Design Tools" buttons near the top.

I'm following these solar discussions with great interest as I'd like to setup a system that will supply power for 3 days with no sun for the following:

a refrigerator (24 hours/day), 
a couple of lamps (3 hours each/per day, CF or LED bulbs)
15 minutes (per day) of some other high capacity load (microwave, for example)

So enough batteries to supply all of above (for 3 days), plus solar panels to refill the battery bank in one day winter or summer. Eventually I'd like to add a small scale wind turbine as supplemental power when the sun isn't shining.

Ideally it would also be grid tied but with a cut off switch to keep it running isolated from the grid if/when it goes down.

Those are my goals, but this is still very preliminary as I know very little and am trying to learn enough to be able to spec out a system at which point I can first see if/when I'll be able to afford it.


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## NaeKid (Oct 17, 2008)

Culex - if what you are hoping for is a grid-tie system, you might want to look at something like a UPS ( Uninterruptible power supply - Wikipedia, the free encyclopedia ) to provide your power for you. There are some units available on eBay right now (search-term: *5000 inverter* will find it or look for member *dcacpower*) that will pass-through 120-volt and will charge batteries attached to the unit. When the power goes out, it will automatically switch-over to the battery-power and continue to provide 120-volt AC to anything downstream. You don't need to worry about back-feeding the grid with this as it is directional-power (only feeds power to stuff attached to the unit).

You can also attach solar-panels and/or wind-generator to the system to keep the batteries alive in case the power goes out for long-term (anything greater than a week).

You can see a picture of the 5000 watt (10,000 watt peak) unit below and there are also 2500 watt (5000 watt peak) units available as well. The best prices I have found are around $600 for the "inverter" (which is more of a UPS-based controller) in 5000-watt draw and only slighly cheaper for the 2500-watt units ...

As as aside: there are some inverters designed for OTG as well that do not have the 120-vac system to charge the batteries and they are significantly cheaper than the ones that have the built-in battery charger.


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## dawnwinds58 (Jul 12, 2010)

I've done alot of "surf, save, and study" looking for wind power ideas. And as I my husband says, I never leave it alone but modify and customize everything. I spent mu whole life in a world that didn't "fit" me, so I'm used to changing things to fit my needs. These 3 links are the plan right now, unless we come up with a better modification.

Link 1- information on building a vertical axis turbine based on the mag/lev design to take friction out of the rotation.

NEODYMIUM MAGNET LEVITATION Vertical Axis Wind Turbine






Link 2- set up multiple vertical axis with no expensive tower, roof mount, that will have rotation no matter which direction the wind comes from and that can handle severe gusting like we get here, freak gusts 50 to 70mph (note, though we like these winged ones made of a boat repair type fiberglass product, I doubt they can survive the gusts we have)

Vertical Wind Turbines Santiago, Dominican Republic






Link 3- user made verticals from metal barrells, but alternate the fin cuts so each one it working counter to the one beside it in pairs to increase wind force between barrels just as you would get a jet effect between two buildings close together, squeeze it and force increases. We plan on changing the design to generator on top, levitated over magnets for ease of turn and securely anchoring the low-rpm generators to the type of structure shown in the Santiago link. It will give better maintanence access to the mechanicals, and the secure mount should keep them quiet. The structure mount also allows weatherheads to cover the mechanicals and take the belts out of direct sunlight. Yes I know belts break, but they also will be readily available if any pulse takes out a vehicle, and there are tons in wrecking yards. In a pinch, leather or hide strips braided will work. (haven't worked out a manual brake on this yet, suggestions??)

Gwindoline - vertical axis wind turbine






Link 4- a low-rpm generator that makes 12volt at 40rpms, that is the icing on the cake, just remember a charge dump is necessary with wind to keep from over charging your batteries

Hurricane Cat 5 MARK I Low Wind Wind Generator PMA

Hurricane Cat 5 MARK I Low Wind Wind Generator PMA


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## CulexPipiens (Nov 17, 2010)

NaeKid said:


> Culex - if what you are hoping for is a grid-tie system, you might want to look at something like a UPS.


Interesting suggestion... I'm quite familiar with them as they are involved in my day job, but had not thought of using one for a disaster... instead I was focusing on the solar panel aspect.

The long term idea is that I can have power in the even of an outage and with surplus feed back to the grid... but if the big one happens, I'd still have some basic power capabilities (lights+) along with working refrigeration... and would continue to have this even if power never came back on.

Utilizing a UPS and a set of solar panels/wind to act as an alternate to the grid charger might be a viable alternative. I'd have to look for something that would play nice with future battery needs but it just might work.

Thanks for the nudge to look at this from a different angle.


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## NaeKid (Oct 17, 2008)

CulexPipiens said:


> Thanks for the nudge to look at this from a different angle.


Not a problem. I only became introduced to this product a short while ago myself. I saw how well something like that would work for powering a fridge / freezer and a furnace-fan. After reading a little further into it, I realized that putting on your own batteries would make for a system that is scalable to personal needs / requirements.

For someone who has a machine that "makes" oxygen - it could mean the difference between life and a slow suffocating death.


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## Nadja (Jan 12, 2011)

mosquitomountainman said:


> Very, very good point!!!! The biggest mistake we see is people trying to live off-grid the same way as they did on the grid. It won't work unless you have lots of money to invest. It's much more economical to cut your needs than to expand your soalr power system.


Forgive me for just jumping in here, but I already do live off the grid and have for about 16 years now. Anybody like some practical and very useful knowledge about this. Forget the so called experts, as most of them live in a normal elect house and work in an elec office. I do not and never will. But my wife and I are pretty much comfy living as we do.


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## Nadja (Jan 12, 2011)

CulexPipiens said:


> Take a look at
> 
> DIY Solar Panel help - tutorials, calculators and design tools for solar power
> 
> ...


It is not nearly as hard as the techies and salesmen types would have you believe. Lets turn this to living totally without the grid. I already do and it is not as hard or as expensive as they would have you believe. There are tricks to it of course, but I have been doing it for about 16 years now, and believe me when I say this, if it can be done wrong, I most likely have already done it and learned from it. I can't tell you watts from amps , but can tell you what works and what doesn't. Period.


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## dawnwinds58 (Jul 12, 2010)

Grid-tie here requires insurance to protect THEIR equipment, and would cancel any savings from being on a grid-tie. We want off. 

How did you set up your system? If it has worked for 16 years, it has stood the test of time, and I'd like to use yours as a working model. 

Would you tell me about it?


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## The_Blob (Dec 24, 2008)

:scratch seems to me that the liability would be on the utility company, since it is their equipment AND installation

State Bill 247 was enacted in Kentucky in 2004, requiring all investor-owned utilities and electric co-ops (TVA excepted) to offer free net-metering to customers with photovoltaic solar-electric installations of 15 kW or less. A single, bi-directional meter is to be supplied by the utility; additional meters or distribution upgrades must be installed at the customer-generator's expense. Excess power generated will be credited to the customer-generator at the utility's normal retail rate.
Kentucky Revised Statutes

The Tennessee Valley Authority (TVA) offers an interesting program through participating Green Power Switch (GPS) Generation Partners. Solar or wind power produced by residential or small commercial generators can sell 100% of their output to TVA for 15 cents per kilowatt-hour. An additional $500 incentive to help offset start-up costs is also available to residential users who qualify.
TVA: Green Power Switch Generation Partners

The Kentucky Solar Partnership (KSP) and the Mountain Association for Community Economic Development (MACED) offer a Solar Water Heater Loan Program, available to both commercial and residential users. It is a monthly installment loan program, with 5% down and a low rate of interest for a fixed term of six years, covering the full equipment and installation cost.


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## Nadja (Jan 12, 2011)

dawnwinds58 said:


> Grid-tie here requires insurance to protect THEIR equipment, and would cancel any savings from being on a grid-tie. We want off.
> 
> How did you set up your system? If it has worked for 16 years, it has stood the test of time, and I'd like to use yours as a working model.
> 
> Would you tell me about it?


For grid tie, you need ins. most likely to cover any damages, but also for the lineman down the street that could be killed should your sell back system be wired wrong.

I am not on the grid or anywhere near one. I have about 16 panels , 12 of which are in the 80 watt range and 4 that are 125 watts. I run 18 T-105 trojan golf cart batteries, 2 trace (xantrax) c.-60's for charge controlers and a 2412 mod sine wave invertor. I also have a 500 watt wind gennie which has it's own c-60 charge controller. I recently bought a 2512 Trace pure sine wave invertor and hope to get it installed today. It will turn on my kohler 7k generator which for now is gas, and soon to be on propane. For most intents and purposes , my entire house runs just like yours does. The only thing different is that I have my refere/freezer and chest freezer on timers so that they are not running at night. As I enlarge my stystem soon I will throw away the timers hopefully.


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## mosquitomountainman (Jan 25, 2010)

CulexPipiens said:


> ...I'm following these solar discussions with great interest as I'd like to setup a system that will supply power for 3 days with no sun for the following:
> 
> a refrigerator (24 hours/day),
> a couple of lamps (3 hours each/per day, CF or LED bulbs)
> ...


When figuring the watt usage of a fridge or freezer you cut the watts down to 1/3 of those listed because the average run time is aobut 30%. For example if the fridge is rated at 900 watts you figure the watt rating when sizing batteries at 300 watts. This will of course vary according to how hot it is where the fridge is operating. Basements tend to be cooler so this might be a good place to put the fridge or freezer if you plan on running it off batteries.

To run on batteries for three days figure up the number of watts you'll need to use to operate without the sun for three days then size your battery bank accordingly. For example: fridge at 300 watts for 72 hours equals 21,600 watts. Five 60 watt bulbs for six hours per day for three days comes to 1080 watts. 15 minutes per day times three days using a 2000 watt microwave comes to 1500 watts. The total watt usage is 21,600 + 1080 + 1500 = 24,180 watts of storage power. Now you know how uch storage capacity your battery bank must have to run those laods for three days without power generation. If you want to be able to recharge the battery bank in one day the amount you drained it in three days you'll need to be able to generate a minimum of the 24,180 watts you drew it down plus the amount of electricity you used during the day and any additional power lost through resistance in the wiring, inverter(s) charge controllers and connections. We'll estimate that number at 8,060 watts (one third of your daily usage). Add 8,060 watts to the 24,180 watts you already used up and you'll need a system producing 32,240 watts to recharge the batteries and allow for the daily amount you use normally. Now figure an average of five hours of direct sunlight in winter you can divide 32,240 watts by five (number of hours charge time) and you come up with 6448 watts. In short, you'll need enough solar panels to charge almost 6,500 watts. That's twenty-nine, 225 watt solar panels. If you can find them at $500.00 each that comes to $14,500 dollars for solar panels alone. The batteries and inverter are the next two big expenditures. And Like the Blob said, add 30 percent to what you think you'll need just to be safe.

As I said earlier it's much more economical to cut your needs than to expand your system. My advice would be a low-draw, energy efficient fridge or freezer with fewer batteries and solar panels and a generator for back-up. If it's a true TEOTWAWKI situation then can whatever is in the freezer that you can't eat before you run out of power.

Now the true cost of providing the power will depend on many things that you'll have to figure out such as the actual watt rating of your appliances, if you use low watt bulbs, amount of sunlight you actually get, etc. Most of us who live off grid use a multi-level system of batteries, panels, wind and a powered (gas, diesel, propane, etc.) generator to balance out the variables. To expect the solar power system to completely recharge everything on a short winter day after three days of cloudy weather adds a bunch to the estimated costs.


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## Nadja (Jan 12, 2011)

CulexPipiens said:


> Take a look at
> 
> DIY Solar Panel help - tutorials, calculators and design tools for solar power
> 
> ...


Unless you intend to buy submarine batteries and lots of them, you will NOT be able to run all you mentioned above for three days of no sun. What most of us do is simply have a back up generator which I will most likely run for a few hours today, as we are getting very little sun. The refer/freezer, tv, computers lights and what not will work just fine by doing this.

Also, the more batteries you have espeically wanting to recharge them all in one day, would require an awful lot of solar panels to be able to achieve this fact. Remember even though you are chargeing your batteries back up for a long night etc, you are also useing normal power during the day, which is robing your batteries of much need fresh fuel.


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## CulexPipiens (Nov 17, 2010)

mosquitomountainman said:


> When figuring the watt usage of a fridge or freezer you cut the watts down to 1/3 of those listed because the average run time is aobut 30%. For example if the fridge is rated at 900 watts you figure the watt rating when sizing batteries at 300 watts. This will of course vary according to how hot it is where the fridge is operating. Basements tend to be cooler so this might be a good place to put the fridge or freezer if you plan on running it off batteries.
> 
> To run on batteries for three days figure up the number of watts you'll need to use to operate without the sun for three days then size your battery bank accordingly.....


Thanks for the lengthy explanation MMM.

Coincidentially I found similar info on line this weekend and spent a number of hours pouring over old electric bills and checking appliances and such. I then ran through all the calcs and checked online sources for parts. Bottom line is that I ended up with a 22 panel system to support the load. The fridge we have is a smaller and very energy efficient unit so the numbers worked out better. Factoring in inverter, charger, batteries and incidentals (wiring, panels, mounting, etc.) I had a total system around 22K and the panels around 14K (very similar to your estimate, I had less panels but I was seening about $600 per without searching much).

I wasn't sure if I had done it correctly or not but now when I compare the process to what you described they match nearly perfectly.

For reference, I'm looking at the fridge listing 3.5 amps on it's label so I calcualted 420 watts for 36 hours (3 days, assumed 1/2 usage per day to account for when it is running) 15,120 watts. Then I cut the bulbs down to 4 - 15watt CFLs (60 more watts) for 4 hours 240 more watts per day (x 3 days) 720 watts and finally I went with 1 hours of misc usage for a 400watt item. I figured this would accomodate a few battery chargers for a full hour one day or a microwave for a few minutes the next day, etc. So, another 1200 watts (400 x 3 days). So about 17,040... lets just say 17K watts for the 3 days. I then put in the overage calcs and the allowance to avoid drawing the batteries completely down and then found products to meet each requirement.

End result it is doable, but not in one big chunk. I'm thinking perhaps getting the base equipment, then adding panels and batteries as funds allow. If there isn't a permanent power loss for at least 3 years I might be able to get enough completed by then to get by although it would take a few more years after that to get the rest of it. I still want to look at ways to tweak it. For example, in winter, I could simply store stuff outside instead of the fridge so even with the decreased solar hours, I'd be able to compensate by having decreased usage of the big item. In summer, the fridge would definitely be hitting the estimates but I'd also have more daily solar hours. And the minor loads would be less likely to be used as there would be more light.

Of course I'll continue canning and preserving and dehyrdrating and such as much as possible but having a working fridge post SHTF would be a nice bonus.  And I hope the solar panels would be less noticeable to the hordes than a running generator would be.

A wind turbine, for about $3k (plus mounting, pole or tower, etc.), and assuming 24x7 12mph wind, would easily also provide the needed power. I was planning to eventually add one to the mix and given the prices it might make sense to get one in sooner rather than after completing the array. Obviously, I'm not going to get the 24x7 wind but even if I got it just 1/4 of the time I'd still be slightly ahead financially vs the price for 1/4 of the panels.

Of course, if I was in one of Jerry's stories I'd have a few million from some settlement or inheritance that I could just have this done turnkey!


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## mosquitomountainman (Jan 25, 2010)

CulexPipiens said:


> .....Of course I'll continue canning and preserving and dehyrdrating and such as much as possible but having a working fridge post SHTF would be a nice bonus.  And I hope the solar panels would be less noticeable to the hordes than a running generator would be. ...


You just have to decide if having refrigeration is worth that much. Refrigeration is a relatively recent innovation. Mankind survived for a looonnnggg time without it. We lived without it for several years. Could the money be spent better elsewhere?

We put our system together a piece at a time. We have refrigeration during the summer and unplug it in winter. The fridge is outside and it's cold enough on winter that we don't need to plug it in. That said, we see it as a novelty. In a true SHTF situation we plan on being able to live just fine without it.


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## Nadja (Jan 12, 2011)

CulexPipiens said:


> Thanks for the lengthy explanation MMM.
> 
> Coincidentially I found similar info on line this weekend and spent a number of hours pouring over old electric bills and checking appliances and such. I then ran through all the calcs and checked online sources for parts. Bottom line is that I ended up with a 22 panel system to support the load. The fridge we have is a smaller and very energy efficient unit so the numbers worked out better. Factoring in inverter, charger, batteries and incidentals (wiring, panels, mounting, etc.) I had a total system around 22K and the panels around 14K (very similar to your estimate, I had less panels but I was seening about $600 per without searching much).
> 
> ...


I have about 3,000 into my first wind turbine and that includes the tower, guy wires and post, trenching, conduit , wire , rectifier and charge controller. I am getting ready to put my second one up now. With an average wind speed of about 12 miles an hour, you are in good shape wind wise. You have already gone with a super efficient refer and are definately on the right track to achieving off grid . When looking at solar, until 2016 , you can get a rebate from uncle sam which is usuaally about 1/3 of total cost over a three year period ON top of that, my state goes yet another 1/3 so it helps out a lot. You want to go top of the line in your panels , charge controllers and inverter no matter what. Stay away from the "bargin" deals especially those made in China , as they are most likely junk. PM me for more personal info on solar/wind Nadja


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## CulexPipiens (Nov 17, 2010)

mosquitomountainman said:


> You just have to decide if having refrigeration is worth that much.


It definitely isn't going to be put over and above the more basic needs (adding to LTS, etc.) and my current plan is to be able to get by without it, however if the necessary funds are available, it is something I'd like to pursue. At the very least, having an applied knowledge of an alternative power system is another skill I'll be able to add to my list once I've set up at least a basic one. I can then work towards the target goal as money and time permits.


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## mosquitomountainman (Jan 25, 2010)

CulexPipiens said:


> It definitely isn't going to be put over and above the more basic needs (adding to LTS, etc.) and my current plan is to be able to get by without it, however if the necessary funds are available, it is something I'd like to pursue. At the very least, having an applied knowledge of an alternative power system is another skill I'll be able to add to my list once I've set up at least a basic one. I can then work towards the target goal as money and time permits.


Sounds like a good plan to me. :2thumb:


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## gypsysue (Mar 27, 2010)

To add to what MMM (my husband) said, yes, we run a refrigerator half the year, but we're in NW Montana. The nights drop into the 40's even in July, so the fridge rarely kicks in at night. 

It's also light out until around 10:30 or so, and light again by 4:30 in the morning. LOTS of solar charging hours. 

But I'd say the cold nights and the fact that the fridge is outside on a covered porch on the north side of our cabin, is the main reason we can run our 10-cf frost-free fridge half the year. The rest of the year we try to keep everything from freezing! 

We didn't have a fridge for many years. We've only had it for a few years. Things like butter and cheese keep well in a root cellar or can be canned. Eggs can be dehydrated. Milk can be powdered or canned. Meat can be canned. Condiments can be kept in a root cellar (ketchup, mustard, salad dressings, etc.). 

If you lose power, long-term, and need a quick cool place, dig a hole and put a cooler in it, and put anything but meat or milk into the cooler. If you don't have a bale of hay or something to set over it for insulation, pile blankets, boards, leaves, anything you can find over it. 

Dig the hole in a shady place, or even under your house in a crawl space if you have one. If you can't dig a hole, use a cooler anyway, and insulate it with mattresses, towels, whatever you can find. If you have cold nights, uncover it at night to help chill it. 

Don't try to keep milk at that temperature longer than a day. Don't try to keep meat more than a few hours at that temperature, and cook it thoroughly when you do cook it. 

Lost your power and aren't set up to can the meat in your freezer? If you're able to, build a fire in your yard and start drying the meat. Cut it into thin strips and hang it from anything you can string or lay over and near the heat, without burning it. Never use plastic for this. Eat the meat within a few weeks if possible. 

This is primitive suggestions. There are many fancier ways of doing these things, but if you run out of time, try these if you have to.


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## CulexPipiens (Nov 17, 2010)

Thanks for all the suggestions GypsySue! They'll be added to my idea list. I've also been acquiring various books on doing/making/etc. without power to further add to my skill set in knowing what and how for a given situation.

On the web I stumbled upon something that was very interesting. A refrigeration system that uses about .1 kwh per day. http://www.energyconservationinfo.org/chestfridge.htm. Click the "chest_fridge.pdf" linke for a nice document on the process. Not sure if this is 100% legit but if I can find some supporting proof, then I could reduce the solar system from $20K+ to well under $5K and perhaps even a fraction of that amount... Although that is keeping in mind there is refrigeration, not freezing, with this.


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## labotomi (Feb 14, 2010)

dawnwinds58 said:


> Could you please relate the patterns of "trickle discharge, and conditioning" as it applies to the use of deep-cycle batteries in an energy array?


Given my time away has cause my memory to fade and that my knowledge was based on a battery bank with much higher voltages and AH capacity, I'd rather just point everyone at a source that can be adapted to any setup.

Normal Charge Procedure

Equalizing Charge Procedure


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