If maximized battery life is what you are looking for, Luminous Tubular batteries are your best option. These deep-cycle batteries are rigged to deliver incredible amounts of power and efficiency. They are suitable for areas with long and arduous power cuts. The life cycle is between 5 to 6 years. An electrolyte level indicator is also included. These batteries are available from 60Ah to 220Ah along with a warranty lasting between 15 to 75 months.