As long as you keep the drain low you can indeed use a shallow cycle battery for storing power and a steady discharge.
Car batteries for solar power storage.
Capacity is the total amount of electricity that a solar battery can store measured in kilowatt hours kwh.
Although a car or truck battery may be used for a small solar power system it may only have a life of 2 to 3 years if used continously compared to 10 to 15 years for a deep cycle battery.
Moreover since the panels produce energy during the day and you may not use all the energy at the time a stable power bank is essential to store this energy.
Most home solar batteries are designed to be stackable which means that you can include multiple batteries with your solar plus storage system to get extra capacity.
Solar batteries are crucial to help you keep your system running.
According to iea s global ev outlook 2016 report more than one million evs were on the road in 2015 globally compared with just hundreds in 2005.
This is very similar to an energy storage system where you may be generating power from solar wind water or magnetic power even as you are using electric devices that feed from the batteries.