Why Lithium-Ion ?
Lithium-ion batteries are safe to keep inside your home, have far superior performance
and are longer lasting that other commercially available alternatives, such as lead-acid or
dry gel batteries, which is why they are used in the SkyLED Smart Energy System.
One of the major advantages of lithium-ion batteries is their long life compared to lead-acid or dry gel batteries. While these batteries have to be replaced every 1.5 to 2 years, lithium-ion batteries last for a minimum of 5 years but can typically go on for more than 10 years.
This difference in the lifetime between the two battery types is due to a difference in ‘cycle life’. A cycle is when a battery undergoes a charge and discharge. Batteries are rated according to their cycle life, for example a battery may have a cycle life of 6000 cycles before its capacity to store energy drops below 80% and it has to be replaced. Cycle life becomes very important in extreme load shedding scenarios where batteries have to be charged and discharged frequently. Lithium-ion batteries have powerful cycle life advantages over lead-acid batteries (6000-8000 cycles versus 1000 cycles) hence they do not require frequent replacement and maintenance.
Replacing batteries is inconvenient and also increases your costs over time. Although, cost of lithium-ion batteries are initially a bit more expensive but in a relatively short period of time they provide a greater economic advantage.
Energy density is a measure of the amount of energy that can be stored per unit volume or mass. Lithium-ion batteries have very high energy densities and can store up to 3 times more energy compared to lead-acid batteries of the same mass or 6 times more than lead-acid batteries of the same volume. This is highly beneficial in situations where space is limited. Due to their high energy densities, lithium-ion batteries are ideal for homes and businesses that have space constraints and high power requirements.
In an unstable grid environment where outages can occur every hour on the hour, it is extremely important that your batteries are charged and ready to provide backup next time the lights go out. Lithium-ion batteries have a much faster charge time as compared to lead-acid batteries, making them the ideal choice for markets suffering from aggressive load shedding, such as Pakistan, India, Bangladesh and other parts of the developing world.
Furthermore, lithium-ion batteries can safely discharge up to 90% of stored energy without significant reductions in battery cycle life whereas lead-acid batteries can only safely provide 50% of the energy stored, without suffering reductions in cycle life.
Lithium batteries have a much greater round trip efficiency compared to lead acid batteries and over a greater charge level range. Lead acid batteries can have a round-trip efficiency ranging from 40% to 80%, depending upon the charge level of the battery. By contrast lithium ion batteries have round-trip efficiencies closer to 100%, over a wider range of charge levels. The greater the round trip efficiency of the battery, the less energy is wasted as it is cycled between charge and discharge cycles. Round-trip efficiency has direct economic impacts for you. If you charge a battery that has 50% round-trip efficiency, then for every unit of energy stored in the charge cycle, you only get half a unit when that same energy is discharged, causing a loss of 50% of the costs of the cycled energy.