There are a lot of different types of batteries in the world. But only a few types are suitable for airsoft electronic guns (AEG). That is because airsoft draws fairly high peak current pulling back the strong main spring. The stronger the spring, the more current the gun draws. In this article, we will discuss the different types of batteries that are suitable for airsoft use.
Nickel-cadmium (NiCd) is the oldest rechargeable battery type. It has the ability to provide high current output. But its energy density is not as great as the newer types of airsoft batteries. Due to its high current output, NiCd batteries are also used in cordless power tools and other high power hobbies. It has a high self-discharge rate, so it is useful the instant you charge it, but not good for long shelf applications like emergency gadgets. Luckily, NiCd batteries can handle high current charging. Therefore a speed charger can quickly charge a NiCd battery pack in 15 minutes. Its charging characteristic is quite tolerant--especially when trickle charged--with very little hazard.
When computing gadgets came about, the NiCd energy density is too low to drive consumer electronic devices for long periods of time. Therefore, the industry invented nickel-metal hydride (NiMH) rechargeable batteries. This type of battery has twice the energy density of NiCd battery cells. And its self-discharge a lot slower than NiCd batteries. The catch is they they provide lower max current output than NiCd batteries. In addition, their maximum charging current is about half of the maximum charging current that NiCd can handle. Combined with doubling the energy capacity compared to NiCd, a speed charger will charge a NiMH battery pack in approximately 1 hour. NiMH has slightly lower charging tolerance than NiCd, therefore a smart charger should be used with NiMH batteries.
Lithium-ion polymer (LiPo) rechargeable batteries are relative recent innovations that have made its way into airsoft. It has the highest energy density of all airsoft batteries. It has almost twice the max current output when compared to NiMH, surpassing NiCd's max current output as well. LiPo also provides higher voltage without needing to increase its packaging by much, a drawback that has plagued NiCd and NiMH batteries.
LiPo batteries are originally invented for computer laptops, where consumer demand for smaller and smaller physical size requires the battery to be in arbitrary shape. Therefore, airsoft LiPo battery comes in assorted sizes to fit all sorts of airsoft guns.
The drawback to LiPo batteries is that its charging tolerance is low. Combined with a potential to catch fire when overcharged and over discharged, safety precautions have to be taken when using a LiPo battery. A fireproof charging bag is absolute necessary. A balance charger that automatically shuts off is almost necessary. An audible discharge monitor is also necessary when using the LiPO battery pack.
Lithium iron phosphate (LiFePO4), or LiFe, is the newest rechargeable battery type. It has all of the characteristics of LiPO batteries, except for the fire hazard risk. Charging and discharging requires similar tender loving care. But when you do overcharge or over-discharge, you only damage the battery and doesn't cause it to burn. Therefore, to keep LiFePO4 batteries in healthy condition, you will still need a balance charger and a discharge monitor. But, thankfully, you won't need a fireproof charging bag.