Lithium Batteries

Scroll down for battery care information.

Features
1. Specially designed for HID
2. Less weight
3. Fast rechargeable

Protection

Note 4&5 may cause destruction of protection board which
is better than an exploding battery.

90 Day warranty applies to all batteries

Advantages of Li-Ion

Li-ion batteries are lighter than equivalents in other chemistries — often much lighter. This is because lithium ions have an extremely high charge density — the highest of all known naturally occurring ions. Li ions are small and mobile, but more readily stored than hydrogen. Thus a battery based on lithium is smaller than one with hydrogen elements, such as nickel metal hydride, and with fewer volatile gases. The ions need fewer storage intermediaries, so more battery weight is usable as charge, instead of overhead.

Li-ion batteries do not suffer from the memory effect. They also have a low self-discharge rate of approximately 5% per month, compared with over 30% per month and 20% per month in nickel metal hydride batteries and nickel cadmium batteries, respectively.

Another advantage is that their lifespan remains relatively unaffected if they are kept "plugged in" after they have been fully charged. Other rechargeable batteries may degrade in these circumstances.

Disadvantages

A unique drawback of the Li-ion battery is that its life span is dependent upon aging from time of manufacturing (shelf life) regardless of whether it was charged, and not just on the number of charge/discharge cycles. This drawback is not widely publicized.

At a 100% charge level, a typical Li-ion laptop battery that's full most of the time at 25 degrees Celsius, will irreversibly lose approximately 20% capacity per year. This capacity loss begins from the time it was manufactured, and occurs even when the battery is unused. Different storage temperatures produce different loss results: 6% loss at 0 °C, 20% at 25 °C, and 35% at 40 °C. When stored at 40% charge level, these figures are reduced to 2%, 4%, 15% at 0, 25 and 40 degrees Celsius respectively.

If the battery is used and fully depleted to 0%, this is called a "deep discharge" cycle, and this decreases its capacity. Approximately 100 deep discharge cycles leave the battery with about 75% to 85% capacity. Except if they have an over discharge protection circuit built in.

Li-ion batteries do not suffer from the memory effect, but they are not as durable as nickel metal hydride or nickel-cadmium designs and can be extremely dangerous if mistreated. They are usually more expensive, since they use a newer chemistry and have more advanced applications.

Guidelines for prolonging Li-ion battery life

Unlike NiCad batteries or NiMH batteries, lithium-ion batteries should be charged early and often. However, if they are not used for a longer time, they should be brought to a charge level of around 40%. Never use the battery care functions some cellular phones provide for nickel based batteries. (This will deep cycle the batteries.)

Li-ion batteries should be kept cool. Ideally they are stored in a refrigerator. Aging will take its toll much faster at high temperatures. Keeping them in very hot cars can kill lithium-ion batteries.

Avoid running the battery through "deep discharge" cycles — that is using it until it's fully depleted to 0 %. This will not happen if there is a protection circuit built in.

Many authors suggest that freezing Li-ion batteries may be detrimental. However, most Li-ion battery electrolytes freeze at approximately -40 °C. Household freezers rarely reach below -20°C. Published experiments demonstrate that freezing (even below -40°C) is unharmful if the battery is fully warmed to room temperature before use. More details are given in the book "Characteristics and Behavior of 1M LiPF6 1EC:1DMC Electrolyte at Low Temperatures" by L.M. Cristo, T. B. Atwater, U.S. Army Research, Fort Monmouth, NJ.

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Storage temperature and charge

Storing a Li-ion battery at the correct temperature and charge makes all the difference in maintaining its storage capacity. The following table shows the amount of permanent capacity loss that will occur after storage at a given charge level and temperature.

Note that it is very important not to store your battery at full charge. A Li-ion battery stored at 40% charge will last many times longer than one stored at 100% charge, particularly at higher temperatures.

If a Li-ion battery is stored with too low a charge, you run the risk of allowing the charge to drop below the battery's low-voltage threshold, and ending up with an unrecoverably dead battery. Once the charge has dropped to this level, recharging it can be dangerous. An internal safety circuit will therefore open to prevent charging, and the battery will be (for all practical purposes) dead.

If you already have two Li-ion batteries for a given device, charge (or discharge) one battery to 40% and place it in the refrigerator or freezer. If freezing, batteries must be allowed to completely warm to room temperature over up to 24 hours before any discharge or charge. Use the other until it "dies", which may be a few years. In the mean time, you may want to check on your cold battery now and again to make sure that its charge does not get too low. Once your primary battery is used to its fullest, take your cold battery out of storage, warm it to room temperature, charge it completely, and use as normal. This will give you the greatest total life out of the pair of them. Better still, don't buy the second battery until you've exhausted the useful life of the first.

Warning

Lithium-ion batteries can easily rupture, ignite, or explode when exposed to high temperatures or direct sunlight. Never store them inside of a car during hot weather. Short-circuiting a Li-ion battery can also cause it to ignite or explode. Never open a Li-ion battery's casing. Li-ion batteries contain safety devices that, if damaged, can cause the battery to ignite or explode.

Source: Wikipedia