Wet batteries are devices that contain liquid electrolyte inside. These are also known as lead acid batteries, flooded cells, or vented batteries. They are commonly used in cars, boats, and backup power supplies. Some synonyms for wet batteries include flooded batteries, vented cells, liquid electrolyte batteries, and lead-acid accumulators. These batteries have several advantages over dry cells, such as a low cost per unit energy, high energy density, and ability to deliver high current loads. However, they require regular maintenance and need to be fueled with distilled water periodically. With advancements in battery technology, wet batteries have become less common in some applications, being replaced with newer, more convenient battery types.