Here is the best batteries for Solar Photovoltaic. I hope this article can be useful
Low Cost Batteries
# Generally, sealed lead acid batteries are the lowest-cost option for a photovoltaic charging system. These batteries, which are common in cars and trucks, can be purchased in both new and used condition. These types of batteries are best for a power system that is not drained constantly but, instead, stays charged regularly.
Long Life Batteries
# Gel-cell batteries, such as those found in boats, offer longer life than their sealed lead-acid counterparts. Unlike car batteries, gel-cells are not damaged when they are drained and charged repeatedly. This makes them ideal for heavy-load solar-charging applications. However, they are significantly more expensive than lead-acid models.
# Users should consider the intended purpose of a solar photovoltaic system before purchasing batteries. A standby backup power system that will stay charged constantly can use lead-acid batteries, while a system that is frequently drained should use more reliable gel-cell units.