People install battery systems for many reasons and likewise people choose battery technologies for various reasons.
For many years people have used lead acid batteries as a known battery technology, particularly in off grid installations. A battery of choice has often been used Telecom batteries which are replaced regularly from telecom installations that need guaranteed UPS (uninterrupted power supply) capabilities. As these batteries are often sold at a vastly reduced cost it is economical for off-grid households to add a large number of batteries to an off-grid system to allow for reduced capacity of the batteries.
Unfortunately, for lead acid battery systems the battery system operates at the capacity of the weakest battery so you are unable to use new lead acid batteries in older systems and would need to replace the whole bank of batteries when more capacity is needed.
Lead acid batteries are well known for having a “falling off the cliff reputation” and degrading very suddenly and quickly, often with no warning. This happens particularly often in cold or hot weather. Coincidentally this is often when batteries are needed the most for heating and cooling. At the same time, most people who live off grid have learnt to manage their electricity usage to only use what is available and to use a generator when batteries are unavailable.
