FREQUENTLY ASKED QUESTIONS
Lead acid batteries have a limited lifespan of about 350 full cycles, i.e. from 100% down to 0%. For this reason, we limit the depth of discharge to 50% when installing lead acid batteries as this increases the number of cycles to about 700.
Lithium ion batteries can be cycled to 0% over 3000 times, giving a much longer lifespan. This is increased to 6000 cycles if we cycle down to 10%.
The lifespan of a typical lead acid battery in residential application is very seldom longer than 5 years. Lithium ion batteries should last at least 15 years and probably more. Lithium ion batteries have a higher energy density, which means they take up less space for the same amount of power, and are smaller and lighter than the equivalent power lead acid battery. In addition, Lithium ion batteries are supplied with an intelligent battery management system (BMS), which helps to maximise the utility, efficiency and lifespan of the battery.
Some solar companies charge up to R7500 to assist with submitting the City of Cape Town declaration for an off-grid Small Scale Embedded Generation system (i.e. a residential solar system). We believe this is unfair, as it is a relatively simple administrative exercise and so we absorb this cost as part of our installation service.
Many companies charge a separate fee of R1500 for an electrical Certificate of Compliance (CoC). As this is a requirement for the City of Cape Town Off-grid SSEG declaration mentioned above, we include it as part of the installation fee.
With the right maintenance, we expect an installation to last more than 15 – 25 years.
Any savings made by waiting will in all likelihood be outweighed by other future price increases, such as the increase in labor, and cost of traditional electricity suppliers. By investing now, you start saving on your monthly electricity bill immediately!