Backup Power | Solar Charged Batteries

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The following is a brief outline (with diagrams and images) for creating your own portable solar panel emergency power station that is small enough to be stored inconspicuously on most patios.

How to Build a Solar Energy Generator for Emergency Backup Power

You can make your own home or office powered solar generator that will give you continuous emergency power.  Think about it!  It will take you about a day to put together and you basically have a power source ready to go at any time that never needs gasoline, kerosene, or any other fuel except the sun.

Basically you will need a solar panel (250 watts), charge controller, battery (deep cycle sealed – maximum storage in amps or watts you can get), inverter (600+ watts with a USB port),and assorted wire and wire connectors.  It will be small enough to fit in a storage closet or set to the side on a patio.


Solar Panel:  The solar panel sits in the sunshine (unshaded) leaning at about a 25-30 degree angle and delivers electricity to your battery via your charge controller.  How much juice it gets from the sun depends on size and location of the panel.  A single 250 watt solar panel is usually plenty.  The good thing about solar panels is that if you need more electricity you can usually hook them up together to deliver more electricity.  Solar panels need to be in direct sunlight (no shade or shadowing) so that depending on location, a partially discharged battery can be recharged each day.

charge controller

Charge Controller:  This device sits between the battery and the solar electric panel and regulates how much charge the battery gets (usually 20 amps).  It monitors the battery and will stop charging once it’s full, so that it doesn’t get damaged.  A charge controller prevents overcharging of the battery.  Controllers are specific to the panel and are universal with amperage limits at 25 amps (12/24 volts).  Use #12 or #10 wire to run electricity between the solar panel and the inverter .  I use #14 wire for emergency short term minimal use power because it is lighter and more flexible.


Batteries:  A large capacity deep cycle battery is what holds the electricity for the system.  If you have large electricity demands you’ll need more than one battery in your battery bank.  I figure that one-to-three batteries hooked together in parallel will be enough to meet my needs in case of a 72 hour power outage.  Granted, one battery isn’t much of a bank, but I’ve pretty much determined at this point that the system isn’t going to get a lot of heavy use.  I figure that one 120+ amp hour deep cycle battery could run what I need in an emergency.  Also, batteries create hydrogen when they’re charging and need to be properly ventilated.  Click here for more battery wiring notes.


Inverter:  This is what actually delivers standard electrical outlet 120 volt AC power to your devices.  It takes the 12 volts of DC electricity from your battery and converts it to 120 volts AC.  These days most small portable AC inverters also have one or more USB ports for direct charging of portable devices.  You want to try to run a couple of devices off this once it is set-up so you know exactly how many hours you will actually get out of the battery and the solar panel.  So for a few days go ahead and have some lights and devices run off the system to make sure they are still running without any problem at all.

A good idea is to put the pieces and parts in a closeable container.  Depending on your area you may need this box to be vented.  You can use a plastic bin with a lid and then put it on the corner of your deck, out of the way.  It will protect the equipment from the rain and sun.  The bottom half of the box will store your batteries and the top half holds the inverter, charge controller, cables, extension cord, etc.  The best option if you may need to move it is a wheeled tool box.

Next – Putting It All Together

1) The first thing to do is hook the inverter up to the battery to see how well it worked.  Plug an electric drill into the inverter as a test, to make sure it runs fast.  After the test you should be able to run your laptop, external speakers, and a lamp or two for two hours of use and you shouldn’t notice much of a drop in the battery’s voltage.  Needless to say if you’re in a black out situation you could run several small items like these.  Many inverters these days also have one or more USB port(s) so you can charge USB devices directly.

2) Once the inverter was connected to the battery, you then connect the battery to the charge controller.  It is important to wire positive and negative wires/ends properly between the inverter, battery, charge controller, and solar panel.

3) Then hook up the solar panel to the charge controller and set the panel outside to start charging.
How big an inverter do you need?  The first thing to do is figure out how much power you’ll need if the power goes out.   *Warning* Geeky stuff follows.

You can usually find the electrical information on the back of the appliance, but if you don’t see it, a trusty Google search can usually help you get the information you need.  My freezer uses 115 volts and 5 amps for a total of 575 watts.  (volts x amps = watts)  I have a 1500 watt inverter, so even factoring in the startup voltage (motors have a higher energy draw when they first start up) I still have enough power in the inverter to comfortably run this device.  I could also run the laptop and a few other small gizmos, but if you tax the inverter too heavily it needs to shut down and allow time to cool off every once and awhile.  Still, the freezer doesn’t run continuously, so it should be fine.

In order to figure out how many solar panels and batteries you need and the rating on the charge controller and the inverter you need to start with what you want to run and then give it a healthy boost because we don’t have sunshine every day.

Two questions to ask yourself are:

1) How many watts does it take to power basic items I will need in an emergency?  Essential items will average 2,000 to 4,000 watts of power to run, but usually not all at the same time.

2) Do I know the difference between running watts and starting watts?  Running or rated watts are the continuous watts needed to keep items running such as lights, TV’s, radios, electronic device chargers, and fans.  Running watts relate to batteries.  Starting watts are the burst of energy needed to turn on something quickly or for a short time, like a blender, microwave, or hair dryer.  Starting watts relate to the size of an inverter.

Power Requirements:

Emergency back-up batteries provide 24/7 blackout protection to supply power during a utility outage. Decide whether you want to back up a few essential circuits/outlets or your whole house or business. The number of circuits you back up and the power requirements of the items on those circuits will determine the quantity of batteries you need.

Broiler1,400Personal Computer500-2,000
Central Air Conditioning2,000-4,000Planer300-900
Chain Saw1,000-1,800Refrigerator/Freezer600-800
Circular Saw1,200-1,600Router100-1,300
Coffeemaker400-800Sanders (belt, disc, orbital)250-1,500
Drills (depends on size)250-1,200Shop Vacuum700-1,400
Electric Furnace5,000-25,000Space Heater1,250
Electric Range (oven only)5,000String Trimmer600-1,100
Electric Range (one element)2,500Sump Pump1,500
Hair Dryer1,200-1,500Table Lamp (tri-lite)150
Heater (radiant)1,300Television100-350
Hedge Clippers300-1,0003/4 HP Paint Sprayer1,800
Hot Plate1,250Toaster1,100-1,700
Leaf Blower1,000-1,400Water Heater3,000-4,500
Microwave1,200Water Pump1,000-2,000
Miter Saw500-1,000Window Air Conditioner600-1,500
Outdoor Lighting500-1,000
* This is approximate wattage only. Please refer to your appliance’s owner’s manual for exact wattage.

Running Watts:  Total your equipment’s wattage requirements from the chart above.  Overtaxing a battery or inverter reduces efficiency and in some cases can damage connected equipment. It’s very important to calculate the power output you need and to give yourself some wattage cushioning for running a few smaller items if need be. If you have the owner’s manuals for the appliances and equipment that you want to run, find and add up the start-up wattages for each item. Otherwise, use the chart and formula above to estimate your power requirements.

Starting Watts:  Multiply the total wattage requirements by two, to determine the wattage necessary to start equipment with motors.  Start-up requirements may be as high as three or four times the running requirements, so it’s best to check owner’s manuals for exact wattages; portable generators offer a higher surge wattage to help accommodate start-up requirements.

Lastly:  Having us ship your equipment anywhere in the US, includes 90 minutes of live video conferencing with you to make sure you know everything you need to know about the set-up and operation.  We will do this via Skype, Join.ME, or any other video conference calling method (on your computer, pad, or phone) to get this completely up and running for you.

60-90 minutes is usually all that is needed if you have no technical or electrical background.  After that set-up usually takes less than 5 minutes (We will also send you a quick step-by-step set-up chart).

$1,295.00 for all of the equipment shipped (plug-and-play) to you pre-wired, pre-tested, and ready to use, and this also includes up to 90 minutes of live video conferencing tutoring (shipping and taxes not included).

$595.00 for up to three hours of live video conferencing (you source the materials yourself via Craigslist, Costco, your local Home Depot, as well as the web).

For more information about:

Portable Battery Backup Power Click Here

Backup Generators Click Here

Watts Used By Average Appliance Click Here

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