What type of battery is most commonly used in aviation aircraft?

Lead-acid batteries are the most commonly used type of battery in aviation aircraft due to several key factors. They have a long history of use in the aviation industry, which has resulted in a well-established standardization around their design and performance. Lead-acid batteries are known for their reliability and capacity to deliver high discharge currents, which is essential for starting aircraft engines and providing power to critical avionics systems.

Additionally, lead-acid batteries are relatively cost-effective compared to other battery types, making them a practical choice for aviation applications. They can also be easily serviced and recycled, which is an important consideration for sustainability in aviation. While newer technologies like lithium-ion batteries are emerging and show promise for certain applications due to their higher energy density and lighter weight, lead-acid batteries remain the predominant choice in many aircraft because of their proven track record, established manufacturing processes, and compatibility with existing aircraft systems.