14500 batteries are similar in size to AA but have higher voltage (3.7V). They're rechargeable and offer capacities up to 1000mAh. AA batteries typically have 1.5V (alkaline) or 1.2V (NiMH). Using 14500 instead of AA may damage devices due to voltage differences. Check device compatibility before substitution. Learn more info. check out here: https://www.redway-tech.com/can-i-use-14500-instead-of-aa/