The short and sweet answer is no. Mixing various types of batteries, or old and new batteries, can contribute to leaking or rupturing, which could ultimately cause personal injury or property damage. It's best to keep like with like. Another tip from Energizer is to replace all. . Here's what you need to know about keeping batteries long-term to maintain their integrity and extend their shelf life. From common alkaline AA/AAA batteries to lithium-ion smartphone batteries, and even to. . When you pick up a pack of batteries and see an expiration or “best before” date, it doesn't mean the battery will instantly stop working after that date—it signals when performance may begin to degrade noticeably. If stored incorrectly, they can lose their charge faster, corrode, or even overheat.