3.7V 250mAh Rechargeable Lithium Battery

Specifications:

• PCB and rechargeable battery pack are available
• This Rechargeable Lithium Battery is used for digital electronics, PDA and others
• This is a high capacity, rechargeable Li-Ion (Lithium Ion) battery with premium cell.
• Do not place battery into hot, dark or under straight of the sunshine.
• Can not be put into fire
• Compact size and easy to carry
• This Lithium Rechargeable Battery is rechargeable and reusable
• Voltage: 3.7V
• Capacity: 250mAh
• Maximum Charging Voltage: 4.2V
• Cycle Life: 500 times

Details:

• This 3.7V 250mAh Lithium Rechargeable Battery is used for digital electronics, PDA, MP3 and others

• The inside electronic circuit is designed with multiple protections, which can prevent over-charge or over-discharge

• Utilized the latest Lithium Ion battery technology, the Rechargeable Lithium Battery has excellent performance

How Lithium-ion Batteries Work?

Inside a Lithium-ion Battery Pack and Cell

Lithium-ion battery packs come in all shapes and sizes, but they all look about the same on the inside. If you were to take apart a laptop battery pack (something that we DO NOT recommend because of the possibility of shorting out a battery and starting a fire) you would find the following:

The lithium-ion cells can be either cylindrical batteries that look almost identical to AA cells, or they can be prismatic, which means they are square or rectangular
The computer, which comprises:

• One or more temperature sensors to monitor the battery temperature
• A voltage converter and regulator circuit to maintain safe levels of voltage and current
• A shielded notebook connector that lets power and information flow in and out of the battery pack
• A voltage tap, which monitors the energy capacity of individual cells in the battery pack
• A battery charge state monitor, which is a small computer that handles the whole charging process to make sure the batteries charge as quickly and fully as possible.

If the battery pack gets too hot during charging or use, the computer will shut down the flow of power to try to cool things down. If you leave your laptop in an extremely hot car and try to use the laptop, this computer may prevent you from powering up until things cool off. If the cells ever become completely discharged, the battery pack will shut down because the cells are ruined. It may also keep track of the number of charge/discharge cycles and send out information so the laptop's battery meter can tell you how much charge is left in the battery.

It's a pretty sophisticated little computer, and it draws power from the batteries. This power draw is one reason why lithium-ion batteries lose 5 percent of their power every month when sitting idle.

Lithium-ion Cells

As with most batteries you have an outer case made of metal. The use of metal is particularly important here because the battery is pressurized. This metal case has some kind of pressure-sensitive vent hole. If the battery ever gets so hot that it risks exploding from over-pressure, this vent will release the extra pressure. The battery will probably be useless afterwards, so this is something to avoid. The vent is strictly there as a safety measure. So is the Positive Temperature Coefficient (PTC) switch, a device that is supposed to keep the battery from overheating.

This metal case holds a long spiral comprising three thin sheets pressed together:

• A Positive electrode
• A Negative electrode
• A separator

Inside the case these sheets are submerged in an organic solvent that acts as the electrolyte. Ether is one common solvent.The separator is a very thin sheet of microperforated plastic. As the name implies, it separates the positive and negative electrodes while allowing ions to pass through.

The positive electrode is made of Lithium cobalt oxide, or LiCoO2. The negative electrode is made of carbon. When the battery charges, ions of lithium move through the electrolyte from the positive electrode to the negative electrode and attach to the carbon. During discharge, the lithium ions move back to the LiCoO2 from the carbon.

The movement of these lithium ions happens at a fairly high voltage, so each cell produces 3.7 volts. This is much higher than the 1.5 volts typical of a normal AA alkaline cell that you buy at the supermarket and helps make lithium-ion batteries more compact in small devices like cell phones.

Lithium Ion Battery Advantages

With their long life spans, Lithium-ion batteries provide an economical choice for powering small portable devices. Found in digital cameras, laptop computers, camcorders and other personal devices, lithium-ion batteries are gaining popularity over other types of rechargeable batteries and disposable batteries. Multi-use lithium-ion batteries are an environmentally friendly option, unlike their close relative, the disposable standard lithium battery.

• Energy Output
• Lithium-ion batteries store more power than other rechargeable batteries, according to Greenbatteries.com. On average, rechargeable Nickel Cadmium (NiCd) or Nickel Metal Hydride (NiMH) batteries that offer 1.2volts of energy are outdone by Lithium-ion batteries of the same weight and size with an output of 3.7volts. The electrochemical potential of lithium-ion batteries provides the largest energy density by weight according to Isidor Buchmann, CEO of Cadex Electronics Inc. of Canada.
• Long Storage Life
• During storage, NiCd and NiMH batteries can loose 1 to 5 percent of their stored power each day, even when not installed in electronic devices. Lithium-ion batteries tend to retain their energy, even after months of storage. Lithium-ion batteries are preferred for travel for this reason. Many sets of batteries can be prepared before the trip and even the last set will be fresh and ready to go after days of storage.
• Low Maintenance
• Since lithium-ion batteries retain no "memory" of power from previous charging cycles, they can be fully re-fueled during a charging cycle. Some rechargeable battery types retain small pieces of information that waste valuable energy storage space and over time make the rechargeable battery hold less of a charge. Storing lithium-ion batteries with at least a 40 percent charge is recommended by Cadex Electronics Inc. of Canada. This adds years to the usual two- to three-year life span of the battery.
• Environmentally Friendly
• Since lithium-ion batteries can be used repeatedly, they create less waste than standard disposable batteries that are tossed in the garbage after depletion. Once lithium-ion batteries have expired, simply place them on a lithium-ion battery charger and allow them to be re-filled with power. After years of use, or when a lithium-ion battery is damaged, it can be recycled. Since lithium-ion batteries contain no liquid electrolyte, there is no risk of chemical burns from a damaged battery.

How Long Does a Rechargeable Battery Last?

• Nickel Cadmium
• There are two ways of judging how long a rechargeable battery can last. "Cycles" are the number of times a battery can be used and discharged before it will no longer function. "Life" is the maximum length of time a battery will stay usable if left in storage. Life and cycle amounts differ, depending on the type of battery used. The three most common rechargeable batteries are nickel cadmium, nickel metal hydride and lithium ion. Nickel cadmium, or "NiCd" batteries, has a fairly high cycle rate. It is around 1,500 cycles, meaning that it can be recharged more than a thousand times before failing. The life of NiCd batteries is around 2 years. However, conditions such as temperature have an effect on the length of time they can be stored.
• Nickel Metal Hydride
• Nickel metal hydride batteries, or "NiMH," can hold higher a capacity charge in the same amount of space, compared to nickel cadmium batteries. These types are common in electric vehicles and consumer electronics applications. NiMH batteries can typically be cycled 1,000 times before they need replacing. However, this can sometimes become shortened if the battery is not discharged and recharged properly. Nickel metal hydride batteries have a life of around 2 or 3 years. Again, temperature and other factors play a major role in shelf life. Storing these types of batteries in an area below room temperature can help extend shelf life.
• Lithium Ion
• Lithium ion or "Li-Ion" batteries are commonly used in advanced electronics, such as laptops and digital cameras. Because of the chemistry used in these batteries, they have a low loss of charge when in storage. Normally, Li-Ion batteries can be cycled up to 1,200 times. While several other types must be completely discharged to retain their capacity, lithium ion batteries do not have this issue and can be charged at any time. Life on the shelf for lithium-ion batteries is usually around 3 years. Older Li-Ion batteries typically will not hold a charge as effectively as fresh cells.

Package Included:

• 1 x 3.7V 250mAh Rechargeable Lithium Battery