The summer brings everyone’s favorite friend and enemy – the sun. People rush to get outside, then slather on sunscreen and hide under large umbrellas so their skin won’t burn. Fair enough – the sun can be tough on everything.
While being outside is peaceful and quiet, there are times music and other entertainments are desired. Radios, TV’s, bug-zappers and laptop computers are wonderful to use but require a great deal of battery power. Instead of using disposable batteries, which fill landfills with toxic waste, rechargeable batteries are used. These take time to recharge though and waiting for that to happen is a pain.
One eco-friendly solution within pocket book reach is to build a portable solar power pack. It doesn’t cost much, can go anywhere and can provide power in an emergency.
Any 12- volt deep cycle battery will store the power for this pack. Most are available for well under $100 in battery stores and online. It needs to be deep cycle because that allows for continuous power use over time instead of the “all-at-once” power of the cranking battery in a car.
Several models are available online and some even have wheels and a handle. These boxes are vented to allow the batteries gas to escape. All lead acid batteries produce gas. The boxes come in different sizes to match your battery and vary in price.
A portable icebox can be used as well- one with wheels and a handle allows the unit to be mobile. Holes drilled into this will allow for wiring and for venting.
Prices have come down over the years so these are very affordable. One 12-volt (adequate) or 16-volt (better) panel is needed.
Solar panels today aren’t stiff board-like panels any more. Some are flexible enough to be rolled up and stored in a carry bag. Be as innovative as you like.
Amazon and other online stores carry panels designed for battery charging that include battery clamps with the panel. These are terrific buys.
DC Input or Plug
With many wonderful products being produced as 12-volt, these can run directly from the battery itself. A DC input which can be purchased at electronics stores or online allows these products to plug in. It looks a lot like the cigarette lighter plug in the car.
They are available as single plug inputs or as double or triple input units. These are the most versatile as they allow more than one device to be used at a time.
To use electronics that require AC power, an inverter is needed. This changes the DC power from the battery into AC. Inspect the AC-powered item to be used- find out the wattage and amperage required to power it. Take this information and match it to the inverter needed. Any salesperson, online or in a store will be happy to help make the right selection.
To find out how much power is left in the battery or to know when it is charged, a 12-volt DC meter is also needed. These are found online and in electronics stores. They are inexpensive. Think of this as a “fuel-gauge” for your power pack.
They can be wired to the battery terminal; some come with battery clips. Check with the salesperson to find the right type of insulated wire to use. Amazon carries a DC meter that plugs into a DC input (see the triple input) to reduce the number of wires going to the battery. This costs around $10.99 as of the time of this article.
Let’s Put it Together
If using an icebox, drill 3-4 holes in the sides for venting. Then attach the DC inputs and meter to the top. Run the wires or connectors to the inside of the box through a drilled hole. These can be sealed with a dab of silicone caulk so they don’t pull out. I tend to go a little overboard and use epoxy and screws as well. No harm in making sure things stay put.
Insert the battery attach the negative wires and clamps to the negative terminal first. This is a matter of safety. If the positive is attached first, sparks will fly (literally) when the negative terminal is attached. Once the negative clamps are in place, attach the positive.
If using a battery box and a luggage stroller, keep the box in place with bungee cords, wire or other means.
Attach the wires to the solar panel and place the panel in the sun. It will take between 5-8 hours for the battery to fully charge.
Once charged, 12-volt or AC products can be used.
Larger systems with more power can be built, but require ammeters, charge controllers, larger inverters, circuit breakers and more. They will be more expensive as well.
When the battery’s useful life is over, it can be recycled by taking it to a battery store when its replacement is purchased. The solar panel can be recycled as well. Check in the phone book for local recycling centers.
This is the most versatile and portable of the power packs. Have fun with electronics this summer and forget about bringing different sized batteries.