How to Build a Solar Battery Charger

A cursory glance at the personal electronic devices market shows a strong consumer's market, with suppliers competing to sell an assortment of battery powered cameras, phones, tablets, laptops and other communications devices.

Keeping those devices powered falls to the supply side of the market, where consumers can easily find both ready to use and build it yourself solar battery charger options.

Single device consumers, for example, seeking extra power for a tablet or a digital camera, can easily find a small, 4-6 watt, solar charger that comes with a supplemental battery. Charger prices can range from $30-$100, and each charger package includes a set of adapters suited to specific device brands.

Substantial increases in solar charger power capacity become more readily available at the top of the price range.

Build it yourself solar charger conversations often start with solar panel cost comparisons.

In the build it yourself solar charger category, the same $100 price range is capable of providing anywhere from double to triple the charging capacity of the more portable, commercial devices.

With solar panels measuring in the 3-4 square foot range, the home built solar charging system remains small enough for placement on most decks, patios and porches.

Building a solar battery charger can be a relatively simple task, involving five separate solar battery charger parts, put together in two steps.

The five solar battery charger parts include:

• Solar Panel: Three different types of solar panels can be found on the market today, silicon based polycrystalline and multicrystalline models, and the non-silicon based, thin film models such as Copper-Indium-Gallium-Selenide, or CIGS, for short.
  
  Most panels in the 6 Watt to 15 Watt range produce sufficient power to charge a storage battery. Costs range from $3/Watt to $5/Watt for polycrystalline and multicrystalline models, and $10/Watt to $15/Watt for the foldable CIGS models.
  
  
• Solar Charge Controller: A solar charge controller insures that the power coming from the solar panel reaches the battery without damaging the battery. Controllers are rated according to both watts and amps, and the controller capacity should be larger than the solar panel capacity.
  
  For example, a 100 watt, 7 amp solar charge controller would be suitable for handling a 12 watt, .7A solar panel. However, that same controller would be too small to handle a 125 W, 7.3A solar panel.
• Battery: For solar battery charging purposes, any 12 volt battery will do. However, 12 volt deep cycle batteries are the common solar battery type because they are built to efficiently discharge a consistent amount of power, over long periods of time, to operate many consumer products.
  
  12 volt batteries are measured in amp hours (ah), and battery charging time depends on the size of the battery as well as the size of the solar panel. Batteries with a higher ah rating provide more battery storage capacity. Larger panels provide more power for faster battery charging times.
  
  For example, in optimal sun conditions, a 12 Watt panel with an output rating of .7A could recharge a 10ah battery in approximately 14 hours (.7A x 14 hours = 9.8ah). A 20 watt panel with an output rating of 1.25A would charge that same battery in approximately 8 hours (1.25A x 8 hours = 10ah).
• Inverter: Inverters are devices for converting the 12 volt DC power to the common 120V AC power used in homes. They typically come with AC plugs. Consumer familiarity with inverters continues to grow as models capable of working in cars for use with personal electronic devices reach the market. Plug an inverter into the car battery socket, or in the case of a solar battery charger, connect the inverter to the 12 volt, deep cycle battery, and it is ready to recharge most personal electronic devices such as laptops, tablets, music devices and cell phones.
• Connecting Wires: Depending on the choice of panel, controller, battery and inverter, three or four sets of wires are necessary to connect the solar charger.
  
  Caution is advised in any activity involving electrical and battery work. Many solar battery charger parts come with compatible wires, making for and easy plug and play process.
  
  In instances where a consumer chooses a different wiring option, the usual connect the red or positive wires to positive terminals and connect the black or negative wires to negative terminals, applies.

With the five parts of the solar battery charger in hand, solar charging personal electronics turns into an easy, two step process.

First, charge the battery by connecting the solar panel and the battery to the solar charge controller.

Once the battery is fully charged, connect the inverter to the battery and plug in your electronic device of choice for recharging.

Experts recommend using only one-half of the battery's charging capacity to keep it in optimal working condition. For example, a quick look at a laptop adapter shows its output as 19v and 3.95A. A 10ah battery (assuming only 5ah are used to keep the battery in top condition) would be capable of running the laptop for a little over one hour or fully recharging a depleted battery.

Small in size, these solar battery chargers can be placed anywhere around the house that receives adequate sun, providing consumers with a green way to maintain their personal electronic devices.

The video provides additional visual help for the building process.

© 2011-2012 Patricia A. Michaels