Electricity outages: battery backup for computers, lighting?
 

For electricity outages I was wondering about battery backup for computers, and a couple lights? I have a UPS system for my computer but that only lasts a few minutes--and those which provide power for a long time seem expensive.

So I am thinking of a deep cycle battery plus inverter? What size?

Or what?

How often do you have to recharge deep cycle batteries to ensure they are not rundown when you want to use them?

Thanks.

Re: Electricity outages: battery backup for computers, lighting?
 

the key to answering the first part of your question is ....how many watts you are planning on using for how long.....

the amount of watts you use will determine the size of the inverter, if you dont know you might want to buy a "kill-a-watt" meter and put it on the things you want to run and see how many watts they are using


the length of time you plan on running them will determine how many and how large of batterys you will need.......batterys for this type of service are rated in AH...or Amp hours

as for maintaining your batterys you can use a battery maintainer type charger that you just leave hooked up all the time

Re: Electricity outages: battery backup for computers, lighting?
 

What do you guys think of this thing? Seems like it could come in handy.

http://beprepared.com/product.asp_Q_...er%20Generator

Power Dome EX Portable Power Generator

When an emergency strikes at home or on the road, you'll be ready with this all-in-one generator. The Power Dome EX can recharge depleted batteries with its built-in cables and inflate tires with the air hose. The work light is a cluster of bright LEDs to provide light for emergencies. In emergencies, blackouts, and campouts, the self-contained 400-watt generator will run appliances or electronics, and it gives you news or music via a built-in AM/FM radio.

1. Automobile Jump-Starter

600 cranking amp jump-starter
Storage area for booster cables
2. Air Compressor

260 psi air compressor
Inflates tires in 5-10 minutes
Tire pressure gauge reader
Sports ball needles included
3. Power Inverter

Two AC plug-ins
Runs a variety of devices
400-watt AC power inverter
4. AM/FM Radio

Allows you to receive critical information in an emergency
Adjustable antenna
5. USB Power Port

Allows you to charge cell phones, MP3 players, Digital Cameras, and other devices
6. Audio Input Socket

Play music or information from external audio sources, such as a television set, MP3 player, or radio with an audio-out port
7. DC Power Source

DC portable power outlet for 12V appliances
AC and DC charging adapters included
Charging time: AC 34 hours, DC 12 hours
8. High-intensity 5-LED Light

Provides a bright light source in an emergency or when you need to illuminate your automobile to work on it

Re: Electricity outages: battery backup for computers, lighting?
 

I watched one of the videos about; it said it could power a laptop for 3 and a half hours. In other words it just has a small battery in it; maybe something like an 18 amp hour battery some of jump starters have. Anyone find the specifications which list the battery size? I couldn't. To me it just looks like one of these jump starters with more features.

Re: Electricity outages: battery backup for computers, lighting?
 

Probably.

I was thinking one of those in addition to a portable solar panel might do the trick. That way you can recharge the battery during the day.

Re: Electricity outages: battery backup for computers, lighting?
 

You need enough battery capacity to last you while the sun is not shining. This unit doesn't have it.

Re: Electricity outages: battery backup for computers, lighting?
 

That is a neat little all in one unit but probably doesn't provide much time for most devices. Most of these portable units have a small battery- less than 20AH. AH is amp hours, and if everything else is the same should give you a rough guideline to runtimes. A 40AH battery should run a device twice as long as a 20AH battery. If my math is correct a 20 AH battery would probably only power that 400W inverter at capacity for 10-15 minutes without excessive battery discharge.

For close to the same amount of money you could buy a deep cycle marine battery, a standalone 400W inverter. and an inexpensive float charger You could keep this unit on your battery all the time to keep it topped off. It would be heavy and not transport well but you would get 5X the runtime of that little unit. Even better would be two golf cart batteries wired in series to provide 12V and about 200 AH.

What is your budget? It's always fun trying to figure out how to spend OPM. :)

ETA: found this battery specs for this unit. It's a 18Ah battery. It's also a good bit cheaper at Amazon.

Re: Electricity outages: battery backup for computers, lighting?
 

I'll delve a little deeper. I'm certainly no expert. But a few things may help.

Look on most devices and it will show the draw in watts or amps. Just remember: Volts(v) X Amps(A)=watts(w)

So if you made it through seventh grade math like I barely did then you probably quickly realize that by dividing watts into volts can help you solve the problem for battery capacity.

So lets say we have a 60 watt light bulb at 120 V

60W/120V= .5Amps (but remember, that's at 120 volts)

Storage Capacity: Batteries store energy at 12V and we convert it to 120V via inverter so in reality to give you a better idea of storage capacity divide the 60 watt light into 12V. So the math is 60W/12V=5amps. To run this light for one hour would require 5AH of battery capacity. But, the inverter is not 100% efficient, so we must add another fudge factor of 10-15% there to account for conversion loss. So lets just say the 60 w bulb draws 5.5 amps@12V Finally the rule of thumb is do not draw batteries down more than 50% of capacity or you risk shortening the life of the battery significantly. So this unit listed has an 18AH battery with a "practical" capacity of 9AH A 60 watt light bulb through inverter would draw 5.5AH. Battery 9/5.5=1.63 hours run time, or about 97 minutes off this pack.

Re: Electricity outages: battery backup for computers, lighting?
 

Some people here have a long way to go lol............

Re: Electricity outages: battery backup for computers, lighting?
 

"Finally the rule of thumb is do not draw batteries down more than 50% of capacity or you risk shortening the life of the battery significantly."

I don't know that this is a major concern if you are only interested in using the unit in emergencies or other rare occasions. Suppose you never used this unit at all? How long would it last? 5 years? How long would it last if you used it a couple dozen times and drew it down all the way some of the times? About the same length of time?

Anyone know?

Re: Electricity outages: battery backup for computers, lighting?
 

Do you ever contribute anything here? (or anywhere for that matter)

Re: Electricity outages: battery backup for computers, lighting?
 

Back up power for this machine is cheepo consumer grade 'CyberPower' 825 VA unit, I removed the original 7 amp hour battery, (about the size of a soup can) and ran a couple leads out from the original battery compartment to a sealed AGM 8D battery.
rated 250 amp hours, it weighs 155 pounds. I expect it will run the computer and monitor for at least all day.
Battery has been in service since 2003, seems to be holding up well.

Re: Electricity outages: battery backup for computers, lighting?
 

Hint: Laptops run off DC. Measure the voltage across the battery and replicate that with a jesusbig marine battery that you charge from a solar cell and you might have a workable proposition.

With a desktop you'll have to play with inverters.

Re: Electricity outages: battery backup for computers, lighting?
 

Most laptops seem to run around 19V. My Asus netbook is right at 12V! I thought about rigging up something so I could connect straight to a 12V battery. (probably never will though)

I've thought about doing this exact same thing! The stuff that I've read is if you run an extended period of time on the battery, the charger built into the UPS can't handle recharging such a large battery. Have you experienced anything like this? Which AGM battery did you get?

Re: Electricity outages: battery backup for computers, lighting?
 

The battery is an 8D marine deep cycle battery. built by exide, sold through NAPA distribution.
measures about 21" long, 11.5'' wide, and about 9.5" tall.
weight around 155 pounds.
A good price on one is anything under 500 bucks.

Re: Electricity outages: battery backup for computers, lighting?
 

From the discussion so far, it seems extremely few GIMERs have a battery backup type system. This surprises me. The vast majority of electrical outages last no more than a few hours. For me the lack of computers and lights is a significant annoyance; conversely for a few hour period of time lack of furnace running, refrigerator running, stove running... is not.

Could anyone else describe their specific battery backup system?

Re: Electricity outages: battery backup for computers, lighting?
 

I am completely off grid, But Nub was the brains of it, I know what I have and how to keep it running but not nearly the expertise you need to get started.

Try this site lots of help there.

http://www.wind-sun.com/ForumVB/sear...earchid=380666

Re: Electricity outages: battery backup for computers, lighting?
 

I have two systems One is two GC batteries hooked in series that provide a total of 220AH of electricity. These are hooked into a Trace DR1512 inverter/charger. This unit is a smart modified square wave unit Just plug it in and hook everything up, it will keep the batteries topped off and switch to battery power almost instantly if 110V drops out. I've had the trace for 10plus years and once had a larger bank connected to it. The second system is a 110AH AGM battery hooked to two unisolar 64W panels via morningstar charge controller. I have an exeltech pure sine wave inverter that I could connect to this system, but don't have anything currently connected to it. I live in the burbs and both systems are underutilized. I'm not even doing anything with the solar panels except keeping the battery topped off.

In theory I would use these systems in a longer term scenario. The primary purpose would be to keep my Engel refer running, and to recharge my NIMH AA batteries for LED lights and handheld devices. But in all honesty for short term situations where fuel access is not an issue I prefer a Honda eu2000. It is much more portable, versatile, and one gallon of gas will run 400W of stuff for 8 hours or more. I guess it just depends on your goals with the system you design

Anyway, good tidbits at both these sites.

http://www.donrowe.com/inverters/inverter_faq.html


http://www.backwoodssolar.com/

PastTense, if you will share with us the watts of the loads you want to run, and how long you want to run them, we can figure out what you need to accomplish this.

the case for a small generator.....
 

If you are prepping for the short term outage of a few of hours, a small battery/inverter system may be for you. However, if you encounter situations where the power is out eight hours or more, you will have to have a way to generate power to replenish those batteries.


I propose The EU series of Honda, 1KW is less than $700, EU2000 is $900. In my area both lightly used can be found on CL fairly regularly for 30-40% less. You can essentially plug up any one item that will plug into a household standard outlet. It will run a refrigerator, or a hotplate, while running these it can also run a TV and some lights. It is poretable enough for camping or tailgating. The EU2000 weighs fifty pounds, less than one good deep cycle battery. Run time calcs- not really needed. A five gallon can of gas will run the device for a few days. The power is a pure sine wave, smoother than inexpensive inverters. Other than price (or perhaps you live in an apartment), what's not to like?

Re: Electricity outages: battery backup for computers, lighting?
 

Lifestyling off grid is one thing.....waiting for the power to come back on is another. When we lose power I tend to turn off the main and enjoy a little quiet time. My many many UPS's are used as buffers, not power replacement.
People pursue their best interests, and keeping things normal (power on, food in store) is in the best interest. When things go down despite the best interest, then my priorities stray away from electronics. God help the folks that need medical devices......

Re: Electricity outages: battery backup for computers, lighting?
 

Whenever I start up my lawnmower in the spring it takes a while to get it working. This is only a minor annoyance since the weather is nice. The thought of spending an hour or more out in freezing weather with high winds trying to a generator running doesn't appeal to me at all. No one has any problems getting a generator running (which hasn't been used for months) under these conditions?

Re: Electricity outages: battery backup for computers, lighting?
 

Thanks. I am ordering one of those Kill A Watt Electricity Usage Monitor meters to see exactly how much load various things use.

What is the best source for batteries? Online suppliers have high shipping charges. Walmart? Auto parts chains?... (I am not near a major metropolitan area, so going there would be inconvenient--but doable if price savings justify it)

Re: Electricity outages: battery backup for computers, lighting?
 

Not being an expert on battery loads and such, I would consider starting with a normal Walmart (or whatever) deep cycle battery with the idea of adding on more batteries of the same type/size later on. I'd rather start with something that could last two hours then save up for (and live without until then) something that will last 8 hours.

Re: Electricity outages: battery backup for computers, lighting?
 

Walmart or local boating sporting goods stores. True deep cycle batteries are supposedly the better battery for this application. They make dual- purpose marine batteries that are also designed to provide a compromise between cranking amps and running low amperage draw devices like a trolling motor. If it has a Cold cranking Amps it is dual purpose. Buy a battery that has rating in AH on it.

Supposedly better than a standard consumer grade off the shelf deep cycle battery is two golf cart batteries. These output 6V so you must wire two in series to provide 12V. They have heavier plates than most deep cycle and are considered a good bank for the buck. I bought mine at Sam's.

The best batteries are industrial types used in some heavy duty systems- brands like Trojan. these are usually available mail order through alternate energy stores/websites.

One more linky -a good site to learn more about batteries than you probably want to know here's the chapter on Lead acid batteries:

http://www.batteryuniversity.com/partone-6.htm

Re: Electricity outages: battery backup for computers, lighting?
 

Got a Honda lawnmower? I run my generators quarterly. No problems yet getting it to crank in under two minutes. Usually by the fourth or fifth pull. I do use gas stabilizer. but I'm also in a very mild climate compared to many of you.

Re: Electricity outages: battery backup for computers, lighting?
 

Got a chinamart 1000 watt 2hp 2cycle generator for $80 at deep discount 2 years ago. It will run my 8 amp large frig with icemaker on a short heavy extension cord. It will also run my computor and equipment without a gilch. Runs 8+ hours on a gallon of mix when hooked to my computor, TV and a couple of lights. Need I have anything more???

Yep, waited till I got another deep discount opportunity at chinamart[Meijers]and bought another one for $76