An 18650 battery is basically a rechargeable lithium-ion battery. They tend to have a low voltage of approximately 3.6 volts and vary in capacity from 1800mah to 3600mah. In a nutshell, the entire name of the 18650 is quite ingenious. It stands for the age-old battery cell which was first introduced about a century ago!
You will discover two main types of 18650 battery cells. The first type is called the Parallel Line Battery or the PVC. These 18650 battery cells are used to power small hand-held devices such as cellular phones, mp3 players and the like. The second type is the Continuous Charge Battery or the CCA. As its name suggests these 18650 battery cells are used to replace the lead acid batteries in heavy duty electrical power supplies.
The overall performance and life of the 18650 batteries will depend on the capacity of the circuit that it is placed in. As a general rule, the higher the load the greater the life and the higher the capacity. As you would be well aware of the capacity is expressed as mAH. Thus, the higher the mAH of the the greater the power supply can be. The mAH rating is in turn denoted by the table indicating the maximum continuous application (C.C.P.) of the circuit.
There are various advantages inherent in the use of the 18650 li-ion batteries over the older lithium-ion battery models. This type of battery has been developed specifically to substitute the old-style alkaline batteries. This means that there is less pressure and heat released during the normal operation of the battery. The general perception from the outset was that this new type of battery was superior to the previous battery types. This perception has now been thoroughly challenged.
The main advantage is that the 18650 battery provides high discharge currents which make the devices that require high currents easier to operate. In addition to this, manufacturers managed to pack more power into a smaller package. It is able to fit into a space that was formerly occupied by the larger and heavier lithium-ion batteries. It has also enabled manufacturers to produce devices that are smaller and lighter, in effect shrinking the form factor of devices.
A major disadvantage is that the higher the mAH, the lower the power density. As a result, devices using the older style of deep cycle batteries would tend to use a high amount of energy but would have low power storage capability. This would reduce the lifespan of the devices. Also, higher power density may have resulted in increased cost and manufacturing costs. As a result, a manufacturer might have considered including a device with a lower mAH capacity as a way to reduce overall cost and improve profitability.
The present situation sees the need for manufacturers to reconsider their earlier decisions and rethink their strategy. The results of current research and analysis would suggest that increasing the capacity by as much as two times (i.e., to fifty percent capacity) will allow manufacturers to address power usage issues while maintaining reliability. As it stands presently, the majority of devices that use standard two-chamber eighteen650 batteries would only need an average of three or four hours of charge for a full charge and performance.
There are a number of manufacturers that have already taken this critical step. Panasonic, for example, has recently introduced a new device called the Pancho Kit. The kit offers a series of batteries in a variety of combinations that include higher capacity cells. They also have introduced a new line of NiMH rechargeable batteries, which boast a higher capacity than the company’s older line of 18650 batteries. All this speaks to the need for manufacturers to revisit their earlier decisions and consider a change to a higher capacity, higher performance batteries.