Lithium Polymer Batteries
Lithium polymer batteries also referred to as LiPo batteries are rechargeable electrochemical cells popular among radio control hobbyists and also used in cell phones, wireless phones, notebook computers, PDA’s and other applications where weight and versatility is a consideration.
LiPo battery packs by weight store more energy than their counterparts. These battery packs are also lighter and retain their charge longer. The energy density and average operating voltage of LiPo batteries of today are two to three times that of nickel-cadmium batteries. Lipo battery packs do not develop "memory," and therefore do not need to be fully discharged before being re-charged. A stack of Lipo cells forms a battery pack, adding cells in a series increases the voltage of the pack whereas adding cells in parallel increases its capacity. One should always observe battery specific instructions when charging and using Lipo packs in order to avoid dangerous situations.
LiPo battery packs by weight store more energy than their counterparts. These battery packs are also lighter and retain their charge longer. The energy density and average operating voltage of LiPo batteries of today are two to three times that of nickel-cadmium batteries. Lipo battery packs do not develop "memory," and therefore do not need to be fully discharged before being re-charged. A stack of Lipo cells forms a battery pack, adding cells in a series increases the voltage of the pack whereas adding cells in parallel increases its capacity. One should always observe battery specific instructions when charging and using Lipo packs in order to avoid dangerous situations.
Charging
Improper or overcharging LiPo batteries can cause out gassing, fire and even an explosion. Explosions can also occur if the battery is short-circuited, as tremendous current passes through the cell in an instant. Furthermore fires can occur if the cell or pack is punctured or otherwise damaged.
Lithium polymer-specific chargers are required in order to avoid fire and explosion
While charging LiPo batteries, the individual cells in the pack should be charged evenly. For this purpose, the cells are to be charged with special LiPo balancing chargers. This entails special care while charging the batteries and additional expenses on procuring the chargers specific to lithium polymer batteries.
Lithium polymer-specific chargers are required in order to avoid fire and explosion
While charging LiPo batteries, the individual cells in the pack should be charged evenly. For this purpose, the cells are to be charged with special LiPo balancing chargers. This entails special care while charging the batteries and additional expenses on procuring the chargers specific to lithium polymer batteries.
Advantages & Limitations
LiPo batteries produce twice the energy, weigh half as much and hold a full charge longer than nickel cadmium batteries. Longevity is a drawback, though, because their life span tends to be only about four years.
Warning!
LiPo batteries can be extremely dangerous if used improperly. They have caused fires in homes and automobiles after erupting during charging or after impact. They are also extremely sensitive to high temperatures and must be properly stored to avoid spontaneous combustion. They should be stored in fireproof containers when not in use, and not left unattended when charging.