Solar panels produce energy from the sun that is immediately available or it may be stored for later use by your electronic device. There are several configurations that you will want to consider when purchasing your portable energy system. For most of our customers, we feel that the best configuration to consider is (a) a solar powered device with integrated panel and rechargeable battery, (b) a solar panel with its own integrated battery for storage, or (b) an independent solar panel configured with a controller and then used with an independent battery for portability and storage.
In all these configurations, an independent battery becomes an important variable in serving your needs. We've outlined several tips for you to think about when considering your needs and portable energy system configuration.
A. Battery and Electricity Flow Control. A Solar panel recharger connected to a battery is generally safer and presents less potential for damage from power fluctuation from a single solar panel connected directly to your electronic device. For instance, on a cloudy day or in cases where an independent solar panel is not equipped with electrical control circuity, fluctuations in energy flow can harm certain sensitive phone, camera or GPS type devices. iPhones in particular may require special control electronics compatible with the device. We feel that a solar panel is best when used to charge up a storage battery rather than the electronic device directly. It is important to check.
B. Convenience for Charging and Portability. During the daylight hours, solar panels can be working for you by gradually charging the battery for use later. Some batteries are small and very portable. Other battery packs are much larger with power capacity to charge multiple devices for long periods of time. In general, an integrated storage battery offers you the all-in-one convenience of a power generator to create power and a battery to store it, for later recharging use. Independent solar panel(s) connected to an independent batter offer the same. Also, having an independent storage battery offers you the flexibility to leave the solar panel at home, hotel or base camp, and take only the battery.
C. Basic Battery Specifications. Your battery, whether internally integrated with a solar panel, electronic device, or independent, is one of the key components in your portable energy system, and it is important to pay attention to the battery specifications.
1. Storage Capacity - Storage capacity is the specification that tells you how much charge the battery can store for later use. How much energy do you need to operate a camp light, weather radio, recharge a phone, camera or GPS device before recharging? You can also estimate the number of times a device may be recharged before the battery needs recharged by knowing the storage capacity of your battery. By comparing the storage capacity of a portable or integrated battery to that of the battery in your electronic device, you can get an idea of how many recharges you have available.
2. Storage Capacity Terminology - Storage capacity unit of measure for a battery is usually stated in the product description or detail tab using milliamp hours (mAh) or Amp hours (Ah). For example, 2200 mAh = 2.2 Ah. Another storage capacity unit of measure you may see is the Watt hours (Wh). To convert watt hours to mAh: (Wh /Volts) x 1000 = mAh. Keep in mind that transferring energy from one battery to another is not 100% electrically efficient. For instance, a power pack batter rated at 2000 mAh most likely will not fully recharge a 1000 mAh electronics battery twice because of normal energy loss.
D. Energy Transfer Power Output Volts - Remember, in order for you to recharge or top off your electronic device, you need a battery pack with enough storage capacity. You also need enough output voltage from the battery to move energy into your electronic device. For electronic devices with integrated batteries, you can check the technical specifications for the battery on PhotonBuzz.com. The fundamental point here is that output of the charging solar panel or charging device (measured in volts) must be equal or greater to the input battery voltage requirement of your electronic device. If the voltage of the battery recharger is lower, you may actually drain the energy from your phone, camera, GPS battery, instead of charging it. This is clearly not good. Check the input voltage of your devices when comparing battery charge outputs.
E. Charging Devices. It's important to remember that most portable battery packs (integrated with a solar panel or not) will charge small personal electronics like cell phones, cameras, GPS devices, mp3 players, and similar small electronics. However, relatively few can recharge a laptop battery. Small electronic devices that can be charged with a USB cable typically need a 5V output rating. Larger electronic devices that require a DC power input (for example, laptops) may need a 12V – 24V output rating. These 12V and 24V battery chargers are available from the largest portable battery pack makers.
F. Battery Technology Options. Portable battery packs vary in not only capacity and output, but also in the type of energy storage technology, size and weight. See the tips below that will help you become acquainted with some options:
1. Nickel Metal Hydride. On of the most common form of battery on portable solar configurations is the Nickel Metal Hydride battery (NiMH). These batteries are most likely to be rechargeable AA or AAA batteries. A battery pack that uses NiMH is a convenient choice for devices that use replaceable batteries like a GPS, camera or headlamp or LED lights. Instead of recharging your device, you simply replace the batteries.
2. Lithium-ion and Lithium Polymers. The Lithium-ion (sometimes Li-ion battery or LIB) and the Lithium Polymer (sometimes as LiPo, LIP, Li-poly) are the most common type of portable battery packs, being the same technology as the built-in batteries in many personal electronic products.
3. Lead Acid. Lead acid batteries are the large, bulky and heavy batteries we think of in an automobile, boat or ATV. These batteries provide the greatest power capacity and output, but are not common in personal solar electronics or small devices.
G. Connectors and Adapters. Remember that if you buy a solar panel with an included battery—either integrated or independent—any necessary connectors between panel and battery will be included. As we have mentioned above, these devices are very convenient and portable and read to charge. However, if you buy a solar panel and battery individually, you will need to check the output voltage levels and the output connector to ensure it is suitable for charging your device directly (if recommended) or connecting to a separate storage battery. Connector options range from a USB (standard, mini, micro), a connector (with a selection of adapter tips) or DC output with voltage control.
We hope this primer has helped get your mind thinking about your battery pack, whether internal or external for you needs. Tells us what you've noticed about your battery and how it is function with your electronic devices.