How Lithium-ion Batteries Work?

The Lithium-ion batteries are more popular these days. These batteries are in products like the laptop, mobile phone, PDAs and other battery operated gadgets. There are also some rechargeable batteries are available.

These batteries are also famous for occasionally blast. These blasts are not happening often. It blasts one or two per million packs. Whenever it happens it causes more damage to the device and surrounding items. If the failure is the increase, the manufacturer recalls the batteries, which cost them millions of dollars.

So the question is why are these batteries are popular, what is the reason for burst and how to prevent from early discharges.

The Li-ion batteries are light-weight with other same size batteries. The electrodes are used in the battery are lightweight lithium and carbon. The lithium is highly reactive material and can store lots of energy in its atomic bonds and this translates into a high energy density. Let’s understand by simple comparison.

The one kilogram of Li-ion battery can store up to 150 watt-hours of electricity and same weight of NiMH (nickel-metal hydride) can store up to 100 watt-hours and a lead-acid battery can store only 25 watt-hours. To store the same amount of energy of one-kilogram Li-ion battery required six kilograms of the lead-acid battery.

The Li-ion holds their charges. It only loses five percent of charge per month while NiMH loses around 20 percents.

The Li-ion battery does not have memory effect means it does not require fully discharge before charging. This battery can handle lots of charge and discharge cycles.

The disadvantage of Li-ion Battery

The lifespan of Li-ion battery is last for two or maybe three years. After the manufacturing, the battery loses it charges whether it is in use or not.

The Li-ion batteries are highly temperature sensitive. As the temperature increases the rate of discharging fast than normal.

Just never completely discharge Li-ion battery if it happens the battery is dead.

Li-ion battery pack required a computer to manage it and this increase the overall cost.

There is the minimum chance to the failure of Li-ion battery and if happens it will burst.

Inside Li-ion Cell

The Li-ion battery packs are available in different shape and size but they all look like same from inside. If you take a laptop battery pack and take apart you will see following items. **

The Li-ion cells look like AA cells or like prismatic means square or rectangular.

There are one or more temperature sensors to monitor battery temperature.

The voltage converter and regular circuit make the safe battery from high voltage and current conditions.

There is a shielded connector that let power and information flow in and out from the battery pack.

The voltage tap, monitor the energy capacity of individual cells.

The battery charge state monitor, a small computer who observes the complete charging process and makes sure that battery is fully charged.

If the battery gets too hot while charging or in use, the computer shut down the power flow and start the cooling process. Like we discuss if the battery pack is completely discharged the battery pack will shut down because the cells are dead. The computer also keeps track of charge and discharge cycle and also sends the information to battery meter which shows the information that charging in the battery.

The little computer takes power from batteries. It is the main reason that Li-ion battery loses its five percent power every month.

**Note: We never recommended taking out laptop battery and taking apart, if you did there may be a chance of a short circuit.

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