An essential part of any renewable energy system is the ability to store energy produced for future use. This is were your battery bank comes into play. Sizing a battery system to match your renewable energy system is dependent on three main factors, the size of your system, how much you intend to store for future use and how many hours needs to be covered. Once we have this information we can design a battery bank that is tailor fit to your needs. You may also use the calculator on this page to help in determining the number and size batteries you will need. Use the calculator below to see what size battery bank you will need. The number of batteries within the bank will depend on power rating (capacity for each battery).
Considerations when getting batteries should include cost, cycle life, installation and maintenance. There are 3 main types of battery technologies available, Lead acid and Lithium-ion. Lithium-ion batteries will deliver more cycles in their lifetime when compared to Lead acid and also provides higher charge and discharge efficiency. Lead acid batteries on the other hand are mostly built for standby applications, there has been recent updates to the technology though and the deep cycle feature is now included in some Lead acid batteries the same as in Lithium-ion batteries.
The battery bank has to be accurately sized to ensure the bank is able to store what you need from your renewable energy system and its depth of discharge gives you the back-up power needed. So while getting the right sized battery system, the option for the type of batteries you need is dependent on what and when you need to use them for. The depth of discharge very important though and should never be overlooked, as it is directly affects the operational life of your batteries. This requires careful planning to ensure what you are purchasing will cover the intended use without adversely affecting the operational life of your batteries.
The concept of salt water batteries or Aquion Energy, on a commercial scale was born in 2008 and since then this technology just keeps getting better. They are robust to any variable cycling profiles and long duration intervals while partially charged. Cycling to maintain performance/life is unnecessary. Its mechanical materials can be recycled in normal recycling streams. Chemical materials can be disposed of without special equipment or containers. There batteries are what we would call all around good and the future of batteries on a whole. They are though, very expensive!
We have given in the above section a number of terms which will have anyone thinking, 'what does this mean?' Well we have you covered, here is a brief explanation of terms relating to battery and battery use:
1. Cycle Life: The cycle life of a battery is the number of complete charge/discharge cycles that the battery is able to support before it's capacity falls under 80% of it's original capacity. Batteries exhibit human-like qualities and need good nutrition, rest and care. Care begins by operating at room temperate and discharging them at a moderate current.
2.Deep Cycle: These batteries are designed to be regularly used and discharging most (70-80%) of its capacity.
3.Depth of discharge: Depth of Discharge, is used to describe how deeply the battery is discharged. This will vary depending on the type of battery; for the lowest rated performing battery you may be able to pull 30-40% of stored energy from the battery, without causing any damage, especially if they are being used regularly. On other batteries you may be able to go all the way to 100% discharge; this can be broken down further with regards to the number of times you can fully discharge your battery. For some batteries you can complete this on a regular basis, with no great adverse effect, others, only occasionally if there be an emergency.