LI-ION AKKUS TIPS UND MERKMALE
Tips für längere lebensdauer(leider nur in english)
* 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.
* Many authors suggest freezing Li-ion batteries may be detrimental. However, most Li-ion battery electrolytes freeze at approximately -40 deg C. Houshold freezers rarely reach below -20 deg C. Published experiments demonstrate freezing (even below -40 deg C) is unharmful if the battery is fully warmed to room temperature before use. See "Characteristics and Behavior of 1M LiPF6 1EC:1DMC Electrolyte at Low Temperatures, L. M. Cristo, T. B. Atwater, U.S. Army Research, Fort Monmouth, NJ."
* Buy Li-ion batteries only when needed. Look at the manufacturing date. That is when the aging process commenced.
* When using a notebook computer running from fixed line power over extended periods, it is advisable to remove the battery and store it in a cool place.
* However, many laptop manufacturers recommend against removing the battery from a laptop while it is plugged in, as this can damage a laptop designed to operate with the battery installed. Some manufacturers are also concerned about dust accumulation with the battery removed. Therefore, check the manufacturer's instructions before removing the battery.
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.#
Permanent Capacity Loss versus Storage Conditions
Storage Temperature------40% Charge----------------100%Charge
0 °C -------------------2% loss after 1 year---------4% loss after 1 year
25 °C------------------4% loss after 1 year---------20% loss after 1 year
40 °C------------------15% loss after 1 year--------35% loss after 1 year
60 °C------------------25% loss after 1 year--------40% loss after 3 months
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, 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.[/B]
Und noch viel mehr nutzvolle info hier:
http://en.wikipedia.org/wiki/LiOn
http://de.wikipedia.org/wiki/Lithium-Ionen-Akku