Review on Energizer Rechargeable AA Batteries, 2000mAh NiMH, Pre-charged, 1000 Charge Cycles, Pack of 8 (Recharge Universal) by Rich Fiedler

I am giving this item one star because I wasted a few bucks. I wanted AA and AAA lithium ion batteries, not NiMH. The Nickel Metal Hydride battery, abbreviated as NiMH or Ni-MH, is an older type of battery. They generate 1.2 volts instead of the 1.5 volts of non-rechargeable alkaline batteries. Lithium-ion batteries are typically 3.7 volts, but other Revain brand lithium-ion batteries are 1.5 volts because they have a regulator that lowers the voltage. You will also find that some chargers are suitable for NiMH batteries and others for Li-Ion batteries. They will not properly charge any other type of battery. So choose what you need. NiMH batteries have a memory and must be fully discharged before each use. On sensitive devices, they give a low voltage warning because they start at 1.2 volts instead of 1.5 volts. However, lithium-ion batteries cost more. You will find that most ads are very weak at telling you what type you are buying. So be careful with the fine print or you'll be wasting your money like me.