Lithium-ion (Li-ion) batteries are very stable and reliable sources of power for two-way radios, laptops and many other devices. Lithium-ion batteries are widely used because they have a high energy density, resulting in a much lighter weight than other rechargeable batteries. Li-ion have other advantages too. They hold their charge well, losing about 5% of their charge per month as compared to ~20% for nickel-metal hydride (NiMH) batteries. Li-ion batteries have no “memory effect,” which means recharging them before they are completely discharged is not an issue. Li-ion batteries can handle many recharges before the end of their useful life.
However, Li-ion batteries have some disadvantages too. They begin to degrade as soon as they are produced, resulting in a 2-3 year life span. Additionally, Li-ion batteries don’t like high temperature. If a Li-ion battery fails, it may rapidly burst into flames. There have been occasional reports of these batteries exploding.
Because every battery depends on a chemical reaction to provide power, it is important to monitor the number of cycle charges and the age of the battery. These factors determine the proper time to replace and recycle units. Old batteries and/or batteries that exceed the number of charging cycles may cause increased internal resistance. These cases of chemical instability often result in excessive – and sometimes unsafe – heat generation.
It is recommended that batteries be tested for safety and capacity regularly on a battery analyzer designed for lithium-ion batteries. If your Li-ion battery has 1000 cycle charges or 5 years after date of purchase, it is well past the time to replace and recycle it. In fact, it would be wise to replace your Li-ion battery every 2-3 years.
Batteries should always be charged and stored in a dry, cool and well-ventilated location. Icom also recommends the following:
- New batteries do not have a full charge when you purchase them. They must be fully charged before use.
- Unless otherwise noted in the charger instructions, do not charge batteries with the radio power on.
- Charge your Icom radio batteries in Icom chargers only.
Battery Storage and Life Cycle
- Batteries in storage for extended periods lose their charge and should be fully recharged before use.
- Remove batteries from chargers when the charge cycle is complete. Continuous charging will shorten battery life.
- Batteries should not be left in chargers in an unmonitored location.
- Batteries lose capacity over time, regardless of whether they are used or in storage. After five years, the battery chemistry can become unstable. Use beyond this range is not recommended.
- Regular testing of batteries with a specified battery analyzer is recommended.
- Properly dispose/recycle batteries after their useful life.
- Using a battery past its useful life increases the possibility of battery failure (e.g. generating excessive heat; causing smoke or flame). Any battery exhibiting these conditions should be removed from the radio and disposed of properly.
- Never use a battery that has been physically damaged or is generating excessive heat.
- Never charge or use batteries above or below operating temperatures of the radio.
- Water or any other conductor across the contacts can short circuit the battery, resulting in smoke or flame.
A lithium-ion battery is a superior rechargeable battery for two-way radio applications. With basic attention to their use and life, these batteries will perform well with Icom radios.
Further reading: Safety Issues for Lithium-ion Batteries (source: Underwriters Laboratories).