Batteries power today’s electronics like laptops, the ever-present smartphone, to even the medical computers vital to many hospital computer systems.  Without them, the device is basically an expensive piece of junk. 

Yet how does a battery work? And why are most using lithium as their key component? Today we cover batteries: the three normally found in most PCs, the advantages of lithium ion, and what are the best ways to extend a Li-Ion battery life.

The Batteries Powering Today’s Mobile PCs

A battery is a piece of hardware that supplies power to a device like a laptop or medical tablet. Computers come with several batteries. The backup battery, also known as the CMOS battery, holds the computer’s settings from its time to date. Without it, users would have to reset the time, date, and other system settings each time they power up a PC.

Another battery is called the bridge battery. This one allows users to keep their computer powered up while removing the main battery and replacing it with a fresh one. This is called “hot swapping” and can be found in computers like those mounted on a Workstation on Wheels.

The most well-known batteries are “main batteries.” Found powering portable or mobile computers, they free users of the device from being chained to an outlet via a cord. Main batteries are often capable of providing power for several hours depending on device use. 

The most popular main battery for laptops is the lithium-ion battery (LiB).  

Lithium-Ion Batteries – Inside and Out 

Lithium is a light, reactive metal that releases a large amount of electrochemical energy. These characteristics and more make it ideal to power light-weight remote or mobile electronics. 

An LiB is made of two electrodes: a positive one (anode) and a negative one (cathode). When the battery is powering a computer or other device, the lithium ions move from the anode to the cathode through the substance called an electrolyte. Rechargeable batteries work by applying a current to the cathode which releases lithium ions which go to the anode. 

The whole charging/discharging process is called a charging cycle: draining a battery to zero percent and recharging it to 100 percent is one such cycle. 

The capacity of a LiB refers to the maximum amount of power it provides to a device from this back and forth process.

Why Li-Ion Batteries Wear Down

All batteries wear out due to the physical and chemical degradation of the electrodes and the electrolyte. An “end of life” for a battery is when the battery capacity drops below what the user would find disruptive in their use case.  For some this could be 50 percent of the original full capacity but others it could be different, just depending on what level of degradation the user can accept. 

For LiB, three major factors affect its useful lifespan: heat, overcharging, and trickle charging.  

Temperature Extreme

High amounts of heat are very damaging to LiBs. While most can withstand a maximum temperature of 60°C (140°F) for a short period of time. Get higher than this and the electrolyte within starts to break down. This reduces the battery’s capacity to move the lithium-ions between the anode and cathode. The longer the battery is kept at these temperatures, the greater chance the breakdown will be permanent.

This does not apply at cooler temperatures (example: 4°C or 39°F). Instead, back and forth exchange of the ions between the electrodes slows down. This reaches a point when there’s not enough electricity produced to power the device, shutting it off. Raising the battery temperature speeds up the exchange and returns power without permanent harm to the battery.  

Overcharging 

This is the process of attempting to push more current into a battery that’s already fully charged. This can potentially cause it to overheat and catch on fire. To prevent such a catastrophe, battery manufacturers have put protective measures in place. Battery management systems and protection chips tell the LiB to stop drawing current once it’s close to a full charge.

Trickle Charging

Trickle charging refers to the process by which the battery is continually topped up to 100 percent. An example would be a LiB-powered laptop plugged in overnight. This bouncing back between full charge and just under 100 percent charge can elevate the battery’s temperature and diminish its capacity and lifespan.

Best Practices to Preserve Li-Ion Batteries 

Companies like Cybernet Manufacturing whose products use LiBs for their products provide guidelines and specifications to their care. Customers using medical computers with hot swap batteries, for example, should:

  • Routinely check the battery’s charge status
  • Swap the batteries early (example: 40 percent) 
  • Recharge them to a maximum of 80 percent to minimize the wear on the battery cells.

Other guidelines like storing LiBs for long-term storage can include:

  1. Store batteries in a cool, well ventilated storage area, away from direct sunlight, moisture and open flame. The ambient temperature should be between 0°C-30°C (32°F-85°F). 
  2. Keep away from ignition sources.
  3. Keep batteries in original packaging or other non-conductive packaging.
  4. Do not store batteries with oxidizing and acidic materials.
  5. Do not store batteries connected to a power source for extended periods (more than 4 days).
  6. Before storing the batteries, make sure to charge the battery between 90 to 100 percent. 

Closing Comments

Batteries have impacted many industries like healthcare by allowing electronics users to move about freely. Lithium-ion batteries are the most popular to power them. 

If your healthcare group is interested in best practices to maintain the Li-ion batteries of their equipment, contact a representative from Cybernet. Also follow Cybernet on Facebook, Twitter, and Linkedin to stay up to date on this and other relevant topics.

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