Battery options

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Battery options, recent changes and how they work.

Batteries provide electric power by discharging energy through voltage potential. Two dissimilar metals separated by an electrolyte create this potential also called a gradient. It allows the electrons to flow freely in the battery cell. The electrolyte separates the anode or the negatively charged metal and the cathode, the positively charged metal. The movement of electrons is what supplies the power to the load or device. Charging the anode and cathode reverses the potential and electron gradient between the two metals rebuilding the difference between the metals and thus recharging the battery. When the charge is removed the battery falls back into it natural state and forces electrons to flow from the higher potential metal to the lower potential metal.

Rechargeable batteries are the standard for energy storage in mobile devices. There are many kinds of batteries however and they are all separated into two categories. Primary cell batteries are non-rechargeable and single cycle batteries. Rechargeable batteries are called secondary cell batteries. Lithium-ion is now the most common due to the high energy capacity.

The principle that drives battery power is voltage differential, this is when two metals are in contact electrons move from the least stable metal to the other metal. These two metals are dubbed the cathode and the anode, or the electron “giver” and “receiver”. The movement of electrons creates a gradient or potential for electrical current. Nickel Cadmium (NiCd) batteries have a shorter life span and are a heavier design with a lower power density,  have been replaced in many applications by Lithium-ion batteries. The cathode and the anode for Lithium-ion batteries are highly unstable metals which creates a steep gradient and a lot of power without the excess weight. Lithium-ion batteries can be formed into a rolled or flattened shape, maximizing space efficiency. These batteries are superior in most ways. However; they are prone to overheating, and a single cell may have more charge than another cell if it’s closer to the power source. A problem that has only recently been remedied with the use of a charge regulating devices built into most Lithium-ion battery cells now.

For secondary cell systems recharging requires a reverse in potential. All batteries degrade from over charging, draining, and time. Most batteries have charging recommendations to maximize life and capacity. For example NiCd batteries are meant to be fully discharged prior to charging since they are subject to a memory affect, where the battery will quickly loose capacity if it is not run through the entire cycle. Newer batteries like Lithium-ion are not subject to this affect which gives them a longer working life and allows for charging at any time.

Chargers in Lithium-ion systems have various ways of capping the energy input so the cells do not overheat or buildup pressure. The safety system(s) shut off electrical flow to the battery by sensing voltage spikes, increased cell pressure, rapid heat increase, and high current pull. Ensuring safe operation and storage of batteries has advanced Lithium-ion battery charging technology. Not only are there four different types of chargers now, that change how fast a battery can be charged from slow, rapid, fast, to ultra fast, but there are smart batteries too. The difference between “smart” and plain batteries is the difference in whether or not the battery can communicate its state-of-charge (SoC) or the level of output potential. The information is collected by a microchip or processor that relays the information to the device they are powering. They are found in most mobile devices now these systems monitor battery performance and keep the user alerted to power usage and remaining battery capacity.