Battery standardization is critical in reducing the cost of aircraft batteries. Past and present methods of battery procurement result in many different batteries that are either to expensive, unreliable or require extensive maintenance. Standardization reduces cost by replacing small numbers of expensive batteries with large volumes of a standard battery. Battery quality and reliability is also improved. The inclusion of new advances in battery technology is also simplified.The use of new battery technology has improved battery performance and increased reliability. Advances such as sealed lead acid batteries and improved separator material have reduced the cost of batteries and increased service life.