http://www.youtube.com/watch?feature=player_embedded&v=AfkajFBynYo There are two main types of batteries: Nickel Metal Hydride (NiMH) and Lithium Polymer (LiPo). While both are widely used by players in the airsoft community, they each use a different type of charger - and sometimes the same kind. But before we explain which charger is compatible for each battery type, you must first understand the basics of each battery. Usually included in most airsoft guns out of the box, NiMH batteries are most commonly used. They are easy to maintain/charge and generally have a higher MilliAmp Hour rating than other batteries. These batteries come in a variety of configurations and can be used to power any airsoft gun. It's important to note, however, that not all NiMH battery cells are equal. It's all ways a good choice to purchase top grade NiMH batteries to increase the life and output of your battery. But if you're looking to increase your AEG's rate of fire, it's time to look into LiPo batteries. Sometimes referred to as Lipoly batteries, LiPo batteries provide very low resistance power to the airsoft gun, which increases performance. This is why they can last much longer between charges than standard NiMH batteries. However, LiPo batteries require more care and require a specific type of charger. Balance chargers, which equally charge each cell of a LiPo battery, are essential to that process. If a single cell overcharges it can quickly overheat, potentially causing the battery to catch fire. Notably, though LiPo batteries increase the rate of fire of most airsoft guns, the increased speed can wear down your airsoft gun faster, which is why it's important to make sure that it can handle a LiPo battery before using one. Unlike Lithium-based batteries, NiMH batteries can be charged without a balancer. Now that you have a better understanding of the two most commonly used batteries, it's time to talk about chargers. Some AEGs come with a battery, charger or both. However, these standard chargers can potentially destroy your battery and, as noted earlier, they can start fires as well (if not properly monitored). The standard wall chargers that come with airsoft guns are never an optimal way to charge your batter. If left unsupervised, these types of chargers can cause damage your battery. This is exactly why it's important to pick up a good charger from the get-go. Generally speaking, smart chargers are the best choice when charging NiMH batteries because it charges the battery in less than half the time and prevents the battery from over charging. Just like eye protection, you want to make sure you get a good quality airsoft battery charger. Smart chargers use an integrated chip to monitor the level of charge, temperature and will automatically shut off once the battery is fully charged. Some smart chargers will only charge certain type of batteries, while others can charge all main airsoft batteries and include the necessary connections to do so. Though some players are on edge about picking up a smart charger, usually due to the price, we suggest pooling in money with your friends to buy one for all of you to share. If money is not an issue, it's highly recommended that you have one on hand. Regardless of what charger you decide to use or what battery you're using, it's important to always monitor your batteries while they charge.