These 3.7 Volt Li-Ion rechargeables are perfect for such applications as: bike lighting, RC toy (cars and airplanes), robots, cameras, DVD external battery, and some for: memory back-up, and use as an external battery bank for MP3s. Lithium Ion Chemistry does not suffer from memory effect. Memory effect can be seen in NiCd (Nickel Cadmium. Information and Product Offerings for 3.7 Volt Lithium Ion Rechargeable Battery Packs Many consumer electronic devices today are powered by battery packs, instead of individual cells. What does this mean? Simply put, a battery pack is a single unit comprised of several (2 or more) individual cells..