Bests & Worsts Reviews from Amazon

[Updated on June 8, 2011] Note: Amazon has moved two of my previous reviews (one for Energizer Lithium AA 4-pack, one for 8-pack) under one page. Therefore I have to update my review to add some new information - or else I look like a fool who says the same thing twice. === New information follows === There seems to be some confusion about those Energizer Lithium AA batteries. Several people have bought those batteries under the assumption that they are rechargeable, only to be disappointed later. Despite the name 'Lithium', those Energizer Lithium AA batteries are very different from the commonly known 'Lithium-ion' rechargeable batteries. Namely: - They are single-use batteries (NOT rechargeable like Li-ion) - The terminal voltage for each cell is around 1.65V (compared to around 3.7V for each Li-ion rechargeable cell) The two types of batteries are not compatible. If your camera accepts AA cells, then you should use those Lithium AA cells and not Li-ion rechargeable battery. Alternatively, you may explore other rechargeable battery options, namely: 1. Low-self-discharge NiMH AA cells, such as Sanyo Eneloop or Sony Cycle Pre-Charged. Those have a operating voltage of 1.25V per cell, so some cameras (especially those that use only two cells) may not operate correctly on those. 2. Nickel-Zinc rechargeable such as PowerGenix AA. Those have higher terminal voltage of 1.65V, same as that of Lithium AA cells. The down-side is that the higher voltage may cause some older cameras to burn out, and the NiZn cells themselves have very poor lifespan. No matter which rechargeable option you pick, remember that they each need their own special charger. Choosing a good charger is the key to longer lifespan for rechargeable batteries. I recommend most people to try eneloop cells first. They are the most reliable among NiMH batteries. If it doesn't work well for your camera, you can still use those celll in other appliances such as flashlights or Wii remotes. Finally, it is a good idea to keep a set of those Lithium AA cells as backup, or in case or emergency. They can be kept in storage for ~10 years!