More and more consumers are opting to switch to solar power solutions for residential application in the face of ongoing load shedding and a need to save on electricity costs. Solar batteries incorporated in these solar solutions allow for the realisation of full off-the-grid living, allowing green and clean energy accumulated from the sun during the day to be utilised at night or when the power grid is off.
Battery PowerZone delves into the topic of solar batteries, answering frequently asked questions about solar batteries.
What is the best battery for solar power?
Solar sealed lead-acid battery
A deep cycle lead acid battery, either a refillable or the sealed option is a good affordable option to be to be linked to a solar array. Lead acid batteries have evolved and remain popular for their large storage capacity, cost efficiency and the fact that they are available in many capacities and application options. Important factors with lead acid batteries is that when sizing them into a solar system, calculations should only allow for 50% of the capacity of the battery to be utilised as a maximum. This is termed DOD – Depth of discharge. The Cycle Life capability is also critical as these specifications indicates how many discharge/ recharge cycles are permissible in a particular battery technology at various depths of discharge e.g., 3000 cycles at 20% DOD, 1500 cycles at 50% DOD, 800 cycles at 80% DOD. Effectively, this is how many times the battery can be discharged and re- charged at the various depths of discharge – in few words the “LIFE OF THE BATTERY.” Lead acid batteries need to be recharged fully in the quickest time after discharge to avid plate sulphation and a direct consequence premature failure
Solar Lithium-ion Battery
Invented in 1985, the modern lithium-ion battery has become the battery of choice for most portable electronics such as cell phones. It has gained a majority share in electric vehicles with leading companies such as Tesla preferring to use lithium-ion batteries. The reason for its success is the fact that it is lightweight, which makes it portable, and if you consider its high energy density and low maintenance requirements, it is the perfect solar power solution.
That being said, its high price remains a barrier for wider adoption in different areas of application. Other drawbacks include restrictions on shipping large quantities of lithium-ion batteries and requirement of protective circuitry to keep the voltage in a safe range as the battery contains flammable electrolytes
These batteries can be discharged by 100% of their capacity unlike the 50% for lead acid batteries. Further, if one for example has a 100-ampere hour Lithium battery, the battery will produce 100 ampere hours until the battery reaches its low voltage cut out level. Lead batteries capacity start to diminish the minute you load the battery, meaning you will not have the full ampere hour capacity for the full duration of the discharge cycle.
A Summary for Lithium Ion Batteries
- Lowest cost of total ownership over extended time periods (no need to replace)
- 50 % of the number batteries can be used as they can be discharged 100%
- There is no adverse effect when subjecting them to PSOC – partial state of charge. If they are not fully charged after use, there is no sulphation build up on the plates as with lead acid
- They will supply the full power capacity of the battery till low voltage cut out – essentially almost double the run times
A very important consideration in the utilisation of Lithium-Ion batteries in temperatures below Zero degree Celsius.
- They can safely be discharged at zero degrees
- They CANNOT be recharged at these temperatures unless some “warming provision” is made
How much is a solar battery?
Solar battery banks can vary greatly in price ranging from as little as R500 to R300k plus. How much a solar battery will cost is dependent on the size of the solar array that it is linked to, the capacity of storage required and the type of battery to be used. The rule of thumb is to ensure that the battery will receive enough charge from the solar panels during an average winter’s day, when the solar panels receive the least amount of sunlight.
It is advisable to do a comprehensive consumption analysis to confirm exactly how much power is used by a household prior to the installation of a fully-fledged solar system with battery storage. A young couple will consume far less energy than a big family that is running a pool pump, for example.
Another factor that weighs in on the solar battery capacity debate is how much power will be needed between sunset and sunrise. A household may use more power in the evenings than a commercial property will, as it is closed at night with minimal power usage. In this scenario, a household may require greater battery capacity than a commercial property may. On the flip side, a property that is in an area that is prone to power outages may be using its battery capacity more frequently during the day, which also affects the battery capacity required.
Making an informed decision hinges on the size and capacity of the solar battery bank that is required, and the subsequent cost, once the numbers have been crunched. There is a lot to consider.
Do I need special batteries for solar lights?
The installation of solar lighting around the perimeter of a building is a handy solution in areas where power is not readily available. These lights have grown in popularity for its versatility in providing ‘powerless’ solutions. Rechargeable battery options utilised in the application of big-scale solar lighting such as flood lights or streetlights are usually more compact and lightweight and is available from Battery PowerZone.
However, the batteries contained within the field of decorative garden-variety twinkling solar lights remain a bit of a myth. People are generally not aware that garden solar lights contain rechargeable batteries, with many landing up in landfills because they ‘stopped working’ as opposed to simply replacing the rechargeable solar battery. Rechargeable batteries utilised in decorative garden lights are the size of a normal AA or even AAA penlight battery and are readily available from retail outlets.
Can solar batteries be recycled?
Solar batteries can be recycled. In fact, it is important for human health and environmental safety for all batteries to be recycled as most batteries are filled with harmful and hazardous materials. A lead acid battery for example, contains lead and sulfuric acid, which can be harmful if not disposed responsibly. The best option is to engage the services of a battery recycling centre who has trained staff along with the necessary equipment to complete the recycling process safely and efficiently.
Can solar batteries be recharged?
Solar battery banks are normally comprised of deep cycle batteries that have high power density, meaning that it can output a large amount of energy. Solar batteries are charged when energy generated by solar panels is fed through a controller into the battery bank.
How do solar batteries work and what is the difference to a normal battery?
Solar batteries normally comprise of deep cycle batteries that have high power density and essential design criteria, meaning they can output a large amount of energy. Solar batteries are charged when energy generated by solar panels and controlled by means of controller is introduced into the battery bank.
Most solar batteries are deep cycle batteries that are designed to provide a steady current of relatively low magnitude for longer durations. This is a desirable feature for a solar power system where the battery may need to power electronics for an extended time. On the other hand, automotive batteries can be damaged permanently if they are regularly discharged below 50% of their full capacity. Automotive batteries or SLI batteries (starter, lights, ignition), prime purpose is to provide a short burst of current and not extended deep discharges. These properties make automotive batteries unsuitable for a solar power system for any reasonable life expectancy.
Can I get solar batteries from Battery PowerZone?
Battery PowerZone has a vast selection of batteries ranging from deep cycle, high cycle and Discover batteries incorporating computer aided grid designs to optimise high power density. Deep Cycle and Solar batteries are ideal for usage in frequent cyclic applications, such as solar power.