The cheaper solution to store power. Although some models are lorry and truck battery look-alikes, their internal structure has nothing to do with an automotive battery. Specially designed for deep cycle use. ideal for the smaller solar setup.
The OpZS batteries are just about the best option battery you can purchase for a decent solar setup. They are extremely long lasting when correctly sized, charged and looked. Although the initial purchase is more expensive than monoblocks, they work out a lot cheaper on a long term.