For devices that can accept individual standard batteries we recommend purchasing quality replacement batteries through local brand name high-volume merchants such as "big-box" retailers and battery specialty stores. For devices with custom size rechargeable battery packs, such as older canister style dive lights and DPV's, our recommendation is to contact the service department of the original manufacturer to arrange a return authorization. For our detailed recommendations on where to purchase and where not to purchase replacement batteries, read our TekTip titled Replacement Battery Solutions.