Familiar sizes, such as AA, AAA, C and D can be found at almost any store imaginable. Concerning cost, rechargeable batteries are a wonderful investment. Rechargeable AA or AAA batteries are known as Nickel Metal Hydride (NiMH). Generally, C and D size are not available in this form.
Watch for the memory effect with your NiCd batteries. The battery life decreases when you recharge the battery before it is fully depleted. So, if you buy a nickel rechargeable battery, make sure you use up all the battery life before you charge it. The aforementioned NiMH battery (especially the new ones) have no memory and can be charged anytime. These are what you’ll generally see in most stores . . . when rechargeable batteries are sold. Choose a lithium-ion (Li-ion) battery if you want to be able to charge it at any time. These types of batteries do not have a memory effect, and they hold their charge for months at a time regardless of when you charge them.
Consider the device you are using the battery for. A high energy item, such as a digital camera, or an LED flashlight will use up the battery quicker than a remote control will.
Look for a charger that is reliable, and utilizes a CC/CV (constant current, constant voltage) algorithm. Some chargers will accept many different battery sizes, and be able to charge both NiMH and lithium batteries at the same time. Most chargers can be used through a wall plug, USB port and even a car charging port.
