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(continued from Part 3. This concludes the article.)

Battery Safety

If you’ve ever watched the news you’ve probably heard stories about exploding Lithium batteries in cell phones, electronic cigarettes, USB battery packs, etc. They’re all true – lithium is an extremely hazardous chemical; it’s poisonous, it’s unstable, it burns extremely fast and hot (>3500F) and it produces hazardous gas when it burns. So why is it used in all of the most common forms of battery electrolytes? Because it has the best cost/size to energy density ratio currently available and manufacturers decided it’s worth the risks, and consumers agree with them.

The underlying cause of lithium batteries catching fire and exploding is thermal runaway, which is an uncontrollable, self-sustaining chain reaction triggered when heat generation within a battery cell exceeds its ability to dissipate heat. For most lithium batteries that starts at an internal temperature of around 175F, but it can be accelerated by mechanical damage, overcharging, external heat, shorting or manufacturing defects. Shorting out a lithium battery is a sure-fire way to get it to catch on fire, and puncturing the casing can cause it to explode.Continue reading“Mobile Device Battery Management – Part 4, by J.M.”

(Continued from Part 2.)

Battery Drain

While I briefly mentioned battery drain earlier it’s worth going into a bit more detail. Drain rate describes how fast a device uses power when a device is in operation. Examples of high-drain devices include things like digital cameras, GPS devices, portable gaming consoles, high-lumen LED flashlights, radios (when transmitting) and motorized devices like power tools. Some low-drain devices include television remote controls, wall clocks, smoke detectors, and red dot sights. Rapidly draining a battery’s charge can significantly shorten its life, so choosing the right type of battery for each type of device is critical.

How fast a battery can provide power to a device is called its Continuous Discharge Rating (CDR) and is measured in amps (A). A related measurement is a ‘C-rate’, which is calculated as discharge current (CDR in amps) divided by the battery’s rated capacity (in amp-hours). C-rate consists of a number followed by a ‘C’ – ‘1C’ means the battery can discharge it’s entire capacity in one hour, .5C means it can fully discharge in two hours, 2C means it can fully discharge in 30 minutes, etc. The higher the C-rate the faster the battery can provide power.Continue reading“Mobile Device Battery Management – Part 3, by J.M.”

(Continued from Part 1.)

Rechargables

Rechargeable batteries come in a much wider variety of chemistries than primary ones, including nickel–cadmium (NiCd), nickel–metal hydride (NiMH) and various lithium-ion (Li-ion) and Lithium Polymer (LiPo) chemistries. It’s important to understand the ‘Li-ion’ and ‘LiPo’ aren’t specific chemistries, they’re categories of chemistries that use Lithium as one of the components of the electrolyte. Li-ion batteries use a liquid electrolyte, are usually cylindrical, and common chemistries include:

• Lithium Cobalt Oxide (LiCoO₂, LCO): Known for high energy density and used in portable electronics like smartphones, tablets, and laptops. It has a nominal voltage of 3.60V with a moderate number of recharges (500–1000 cycles), and a thermal runaway temperature of 150°C.
• Lithium Manganese Oxide (LiMn₂O₄, LMO): Offers high power and improved safety compared to LCO, often used in power tools and medical devices. It has a nominal voltage of 3.70V (3.80V), and a recharge cycle life of 300–700 cycles. These are frequently referred to as ‘IMR’ batteries.
• Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO₂, NMC): Balances high capacity and power, with a nominal voltage of 3.70V. It is widely used in electric vehicles (EVs), e-bikes, and industrial applications, with a recharge cycle life of 1000–2000 cycles.
• Lithium Iron Phosphate (LiFePO₄, LFP): Known for safety, long recharge cycle life (1000–2000 cycles), and a flat discharge voltage, and a nominal voltage (3.20–3.30V). It is used in stationary energy storage and high-current applications.
• Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO₂, NCA): Used in high-performance EVs, with a nominal voltage of 3.60V and a recharge cycle life of 500 cycles.
• Lithium Titanate Oxide (Li₂TiO₃, LTO): Features exceptional recharge cycle life (3,000–7,000 cycles), fast charging (up to 5C), and wide temperature range, but it’s currently the most expensive. It is used in UPS systems, EVs, and solar street lighting

Continue reading“Mobile Device Battery Management – Part 2, by J.M.”

There have been many articles by myself and others on SurvivalBlog that discuss the use of mobile electronic devices such as radios, flashlights, cell phones, red dot sights, drones, cameras, etc. for emergency preparedness and disaster scenarios. The one thing all such devices have in common is that they require power of some sort, usually in the form of a battery, and without power those devices are about as useful as a paper weight (I guess you could use them as projectiles). Understanding how batteries work and how to best manage them can help ensure you get a long and useful life out of those critical devices.

A battery is basically a way to store electricity using chemicals and typically consists of three components – an anode, a cathode, and an electrolyte chemical that the anode and cathode are immersed in. The anode releases electrons, which flow through whatever device the battery is connected to and back to the cathode, creating an electric current. Simultaneously, ions move through the electrolyte from the cathode to the anode, which is a substance that allows ions to flow but not electrons, to balance the charge. This process continues until the chemicals within the battery are depleted, at which point the battery is considered “dead” and needs to either be disposed of or recharged.Continue reading“Mobile Device Battery Management – Part 1, by J.M.”