The best way to go about it when getting any renewable energy system is to identify the actual and real needs of the user and build the system around them. When choosing the right solar batteries to use, the same thing applies. One has to know to what extent the solar batteries are to be used and what kind of requirements the owner is having before choosing among the different types and sizes.
What type of system will the solar batteries be used in?
There are typically four common types of set-ups of a solar power system. These are:
1.) Back-up system
This installation uses solar power systems to provide needed electricity in the event of outages. Since outages often times do not last for more than 24 hours, solar batteries required for this system need not be high capacity types.
2.) Partial use
This is a set-up where a selected set of appliances are wired or connected to the solar power system as its main source of energy. Like the back-up system, solar batteries that are usually called leisure batteries, are used for this type of set-up.
3.) Grid-tied or grid-interactive
This set-up gives the system the capability to feed a load from a solar power system and the main grid system simultaneously. Should the circumstance arise where power generated by the solar panels exceed the actual need, and all solar batteries already have been fully charged, the excess power is fed to the grid. On the other hand, when solar power supply is low, the system can get the extra power needed from the grid. Depending on the reliability of supply from the grid, small to medium capacity solar batteries may be used.
4.) Stand-alone systems
This is a set-up where electricity is fully supplied by the solar power system. The type of solar batteries to use for this set-up will now depend on the use of the system. If it is just for a hunting cabin that only gets to be used for short periods in a day, small capacity solar batteries may be used for homes and small processing units, where intensive use is constant, industrial type batteries would be ideal.
Solar battery types and specifications
Aside from the size and degree of use, there are also other considerations that you need to look into when purchasing and choosing the right solar batteries for your solar power system.
Batteries are built for many applications. The renewable energy industry is a relatively new field and many manufacturers may not have perfected the technology for solar batteries. It is safe to choose manufacturers that are trusted when it comes to renewable energy technologies. It would also be good to check-out the list of batteries in the manufacturer’s list. In most cases, manufacturers have a separate list of batteries that are appropriate for renewable energy application.
These are numbers and letters that producers use to “name” a set of batteries with similar characteristics, and distinguish them from other battery lines that may be designed for another application. It is always recommended to use batteries with the same model numbers within a battery bank. Mixing different models of solar batteries may create imbalances which might lead to poor system performance or premature system failure.
There are several battery types that are used in many applications but can be used in renewable energy systems as well. These are:
Flooded lead-acid or FLA – these are the most commonly–used solar batteries, particularly for off-grid or stand-alone types of systems. They are also least expensive but may require a certain degree of maintenance when operating. Depending on how deeply they are cycled, distilled water will need to be added to the battery cells on a regular basis. However, with proper preventive care and maintenance, these battery types could last for a long time.
Valve regulated lead-acid batteries or VLRA – they are also known as sealed batteries. There are two types of VLRA solar batteries. One is the absorbed glass mat (AGM) lead-acid battery. The AGM have very similar chemistry with the flooded lead-acid batteries. The difference is that these batteries don’t need to be regularly refilled with distilled water. The downside is that they have a relatively shorter life span and may be more costly compared to FLA.
Gel cell batteries – The same is true for the second type of VLRA which are the gel cell batteries. These are sealed batteries and do not need refilling. However, since gel electrolytes within the cells cannot be replenished, they may not last for periods longer than the FLA types. Both types of sealed batteries required light charging to avoid drying out the cells.
You might wonder why some people would choose the more expensive sealed batteries over the FLA which can be used for a long time. The reasons may vary but oftentimes, the battery type with the maintenance free features is the most popular. Especially as FLA batteries, when not maintained properly may be outlasted by the maintenance free types.
Dimensions and Weight
When designing the battery bank, the length, width, and height of your batteries will be a major factor. This factors in the total cost of your solar power installation as batteries are usually bulky and heavy. When designing the containment areas, it is a rule of thumb to allow for a one-half or one inch of space in between the batteries. This will help in regulating the temperature of the batteries especially during heavy charging regimes.
As most batteries can be heavy, floors within containment areas need to be sturdy to withstand the total weight of the battery bank. It is also important to remember that the batteries will have to be moved at one time or another.
Warranty and After Sales Service
Manufacturers all offer warranty for their products. Five to eight years is the usual length of time that their warranties cover when it comes to these types of batteries. Solar batteries with longer warranty periods are guaranteed to be heavy-duty and have a long life.
The quality of after sales is also another important consideration. The promptness of the service, the skill of the technicians and the proximity of the service centers are things that you should look out for. Complex installations such as a solar power system often require service at one time or another whether it is preventive maintenance or repairs. It is good to have a trusted service provider that is ready to respond with a single phone call.