Lithium Ion Battery

This section describes the general guidance on care and expected lifetime of the Lithium Ion Battery used with the Vocera Badge. Vocera batteries can be used for approximately 18 months after which it should be replaced.

A key reason for replacement is due to the charge capacity of the cells diminishing over time as they undergo discharge and recharge cycles, resulting in a battery not being able to support powering a badge for a full work shift. Another factor is the 24x7 operation of Vocera badges where batteries are frequently moved between many badges during their operational life. The continual handling of the batteries introduces a much higher likelihood of physical damage that may occur to the batteries.

Batteries are consumable items and as with most Lithium Ion batteries used in mobile electronics, the structure of the Lithium Ion cell inside the battery pack degrades over time. Consequently, metal impurities in the cell can cause the cell to be more susceptible to internal shorts. If an internal short occurs, the Lithium Ion cell may experience thermal runaway creating heat and releasing gases that can cause the plastic enclosure of the battery pack to melt.

The gases caused by the thermal runaway event could contain oxides of carbon, aluminum, lithium and copper. Although these gases are released in small quantities, they may be toxic and should not inhaled.

The gases released and the visible damage to a battery pack during a thermal runaway are expected and do not indicate that the battery has caught fire. However, among the gases that might be emitted is Hydrogen and if exposed to a spark or naked flame, this may cause combustion. To mitigate this,Vocera battery chargers are built using flame resistant PC-ABS and each battery slot is isolated from adjacent slots. These events may be alarming if you are not familiar with the characteristics of Lithium-Ion batteries. These events will usually occur only when a Lithium-Ion battery has been in operation for far longer than its intended lifetime.

As a general guideline, Lithium-Ion batteries should be replaced every 18 months, and no Lithium-Ion battery should be in service after 3 years of use. Any battery that displays physical damage should be discarded to avoid the battery cell getting damaged and triggering a thermal runaway event.

To understand the health of batteries, Vocera battery chargers use LEDs in the charging slots. If the charging LED is blue or flashing blue, it indicates that the charge capacity of the battery is down to 60% and the battery should be replaced soon. If the charging LED is red, it indicates that the battery did not recharge completely within its allocated timeframe. In this case, Vocera recommends removing and reinserting the battery to check if the battery completes its charge cycle. If the LED returns to a red state, the battery should be removed from use.

For any incident of a battery displaying signs of thermal runaway or damage while in a battery charger, contact the Vocera Technical Support team to RMA the battery and battery charger to investigate the incident.