Thursday, March 25, 2010

The charging of lithium-ion batteries B

The charging of lithium-ion batteries B

Some chargers promise a fast charging lithium-ion Dell laptop batteries in one hour or less. Such chargers skip Step 2 and go straight to "Ready / Ready" at the end of stage 1 At this point, however, the charge level only at about 75%. The achievement of the full charge requires I.รก. times longer than level 1

There is no floating charge created as stand lithium-ion Dell RN873 do not overcharge. In their place, a short Endladephase is added, which compensates for the small self-discharge of the battery and the power requirements of the protection circuit. This Endladephase may need to be repeated every 20 days, depending on the battery. In general, the charging process is active when the open terminal voltage drops to 4.05V/Zelle, and turns off when the terminal voltage has reached 4.20V/Zelle.

But what happens when a battery is inadvertently overcharged? Lithium Ion Dell hd438 , Dell KD186 is built to operate safely within their normal voltage range, but it becomes unstable if it is charged to higher voltages. When is charged via 4.30V/Zelle, formed on the anode, a metallic lithium layer, the cathode material begins to oxidize, losing the stability and development of oxygen. Overloading leads to overheating of the cell. If this is ignored, can lead to inflammation.
It will be made great efforts to avoid overloading and deep discharging too.

Commercial lithium-ion batteries contain a protection circuit which limits the charging voltage on 4.30V/Zelle, 0.1V/Zelle higher than the threshold voltage of the charger. A temperature sensor shuts off the process when the cell temperature reached 90 ° C, and a mechanical pressure switch interrupts is definitely in the charge circuit when the safety threshold is reached for the pressure. Except to the spinel batteries () magnesium-based, which contain one or two small cells.

Extremely low voltages must also be monitored. The protective circuit is so constructed that it also interrupts the circuit when the battery is inadvertently discharged below 2.50V/Zelle. At this voltage the protection circuit will disable the laptop battery and recharge with the help of an ordinary charger is no longer possible.

There are various measures to prevent deep discharge. The device protects the battery by interrupting the discharge has reached a voltage of 2.7 to 3.0V/Zelle. Battery manufacturers ship the Dell Inspiron 6000 Battery with a capacity of 40% to allow for self-discharge during storage. Technically better batteries contain a "Weckschaltung", where the protective circuit only allows a flow of current after the battery has been reactivated with the help of a short charge. This allows for longer storage.

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