A turn-key, portable solar power system that is assembled in the Powerenz shop in Georgia, USA, may include a few types of battery chemistries, primarily lithium or lead acid. Lithium and lead acid batteries have pros and cons. In this short very basic overview, we will focus on lead acid batteries. Lead acid batteries come in liquid, spillable and non-liquid, non-spillable forms. In our portable systems, the non-liquid forms are used. Other terms that are used to describe the non-liquid form include marine, deep cycle, AGM, and gel. Compared to lithium chemistry batteries, lead acid batteries are heavier, less expensive to build, though more expensive to ship (weight), are able to discharge a smaller percentage of their total rated capacity, and cannot endure as many charge – discharge cycles as lithium batteries. For the user of portable solar power who does not mind the increased weight of a system that utilizes a heavier lead acid battery, who does not mind the less expensive “open architecture” set-up, and who does not want to pay the increased cost for a system that utilizes a lighter-weight lithium battery, lead acid may be the better choice. A perfect example of a scenario where a lead acid system might be preferable would be a car-camping adventure (weight is not an issue) where the campers’ budget cannot meet the cost of a lithium chemistry system.
Very small lead acid systems can be enclosed in soft bags or carrying cases, backpacks, or other non-hard case enclosures. As the size and weight of the lead acid battery increases, the system must be enclosed in a hard case for obvious reasons. In a typical hard case system, the battery and other supportive electronics are mounted inside the case, and all of the components are covered by
a fancy, neat and clean, labeled “top panel” that is mounted to the case. The top panel hides the electronic components that are below it and makes the inside of the case look high-tech and neat. Top panels are cosmetic, give an appearance of organization, and may impart a sense of quality, but they require a great deal of extra work to install and they add to the cost of the system. With or without a top panel, the system functions the same. In the absence of a top panel, the appearance of the system in a hard case can be referred to as “open architecture”, and the end user has visual and physical access to all of the components of the system. Many of our clients prefer the open architecture assembly. They enjoy working on their own systems, seeing and testing the components, and having a better understanding of the structure and flow of electricity within. The open architecture design is less expensive.
Lead acid batteries are generally safe in wet conditions, waterproof, and resistant to salt water and salt water mist. On the other hand, many of the electronic that are necessary components of the system are not waterproof or resistant to salt water. For those users who require that the electronics be protected from water, a hard case enclosure that is rated for water exposure/immersion is necessary. In addition to protection against water, a hard case can provide protection against dust, dirt, wind, blunt trauma, smoke, insects, and animals.
Lead acid batteries are very easy to charge using a variety of sources of power, including AC via the utility grid, DC, and a solar panel. To recharge a lead acid battery using a portable solar panel, one additional electronic device is necessary, and that is a solar charge controller. A solar charge controller establishes an electronic relationship between the solar panel and the battery. It processes the electricity that is produced by the solar panel, and makes it appropriate for charging the battery. Add some good wiring and sunshine, and the end user will be the one who has power.
In the event that the battery completes its lifespan, a “dead” lead acid battery is simple to swap for a new battery. Lithium batteries are more complicated and expensive to replace, though they do not need to be replaced as often.