• AA batteries have a few options for power and ability.set of batteries image by KtD from Fotolia.com
  
  Metal detectors need powerful batteries to run for a long time. When you use a metal detector, a powerful AA battery will last longer than a low-power battery which is drained of power quickly. While AA batteries are not typically the most powerful type of batteries available, there are some batteries that are more powerful and longer-lasting than other batteries.
  
  

Nickel-Metal Hydride

• Nickel-Metal Hydride, otherwise called NiMH, batteries are a rechargeable and powerful AA battery option. The batteries have a high capacity for power and are ecologically friendly since they are not thrown away, but are instead recharged for later use. For a metal detector, which uses four to eight batteries at a time, a NiMH battery with charger is a powerful and efficient option.
  
  

Alkaline

• Alkaline AA batteries are considered the standard battery. These are cost effective, and some manufacturers suggest the use of alkaline batteries for their devices. These are powerful batteries, but they are not rechargeable. According to Battery Guide, alkaline batteries come in two options: regular and high-drain alkalines. For most metal detectors, the high-drain option is the best.
  
  

Lithium

• Lithium batteries are the most powerful battery options on the market. They are not rechargeable and they must be given to a hazardous waste facility when the charge runs out, because they contain toxic chemicals. Lithium batteries will last much longer than any other type, but they are not environmentally friendly and are expensive.