A recent uptake in loadshedding, coupled with current availability of affordable, reliable, and energy-efficient alternative power equipment, has seen more South African consumers purchasing batteries for home use and storage.
With a selection of affordable, high performance, modern and legacy products, home buyers must come to grips with the unique properties and use cases for each type of battery under consideration.
To help consumers make better power technology choices, Matthew Hall, product director at Rectron South Africa, offers the following basic guidelines when buying and using a battery to power the home or to store electricity from alternative sources, like solar.
Charging and discharging (usage) hours
While some options may be more affordable, they don’t possess the durability and prolonged lifespan necessary for powering a home regularly over an extended period.
With longer periods of outages and limited opportunities to charge the battery packs due to short periods of grid availability, traditional lead acid (LA) batteries are more suitable as an uninterrupted power supply (UPS) during stages 4 or lower.
Beyond stage 4, when there are shorter grid uptimes, an investment into Lithium-ion (Li) offers greater usability, resilience, and return on investment.
Lead acid still has a place
The lead-acid battery’s affordability will sustain its appeal provided it is housed properly in a dry, ventilated space and used well. It is perfect as an interim UPS solution in critical service environments, like data centres, hospitals, and banks.
Here, the battery is only discharged for short periods as systems switch over to alternative sources, like diesel.
Depth-of-Discharge (usable capacity)
An important consideration when choosing a battery, that most people are not aware of, is the depth of discharge rating, or usable capacity.
This percentage value measures how much of a fully charged battery can be used before it begins to negatively affect its life cycle significantly. At this point, it must be fully charged again, which varies greatly according to type.
Lead-acid (LA) batteries are typically much more affordable than Lithium-ion (Li) batteries, but they also have a lower depth of discharge of around 30-50.
* When 30% or less of the LA is used in a discharge session, it can last up to five years and endure 1 200 charging cycles before it is unusable.
* When 30%-50% is used, the number of cycles drops all the way down to around 500 cycles.
* When 100% of the battery is used each time, the number of cycles drops to under 200.
This means that, at Stage 6 or beyond, when used multiple times a day, with shorter charging and longer discharge periods, the battery may not last beyond three months from purchase, as consumers unknowingly regularly discharge it far beyond its 30%-50% range.
Added to this is the fact that LA batteries are much slower to charge, with the shortest period being six hours to fully charge, as the chemicals inside are much less tolerant to heat.
Home users looking to invest in a long-term energy storage solution are increasingly considering li-ion batteries despite their higher cost. By leveraging various payment options and incorporating these robust, longer cycle batteries into a comprehensive solar system, the higher initial capital outlay pays for itself in savings in as little as 12 months.