Most of today’s modern mobility scooters require two, 12-volt, deep-cycle gel cell batteries that are sealed and free from maintenance. Gel cell batteries were developed to stop the battery from leaking acid (like when they used wet cell batteries). Gel cell batteries are sealed and dry with no potential for spills. The silica gel suspends the acids (electrolyte) in the battery so if it is broken or punctured it will not leak. Gel-cell lead-acid batteries were developed to be maintenance free and should be approved for storage on most airlines and cruise ships. The disadvantage of gel-cell batteries is that they usually have less capacity and are more expensive.