Posts Tagged ‘temperature’

The temperature and battery charging 3: battery recharge cycles

March 6th, 2010

Be lowered in the second phase of the charge cycle, the charging current, however. The ability to absorb the load is progressively reduced when increasing the charge state of the battery. When the Sony VGP-BPS9 Sony VGP-BPS9/B charge current at too high a value remains in a later stage of the charge cycle, the excess energy is converted into heat and pressure in cells. Finally, a leak will be created to allow escape of oxygen and hydrogen. The escaping gases cause damage not only the electrolyte, they are also highly flammable! A white substance in powder form accumulates around the leak, and indicates where the gas has escaped.

An Ultra-fast charging can only be used in batteries, which are designed for fast charging. The application of high charging currents on Normalbatteriezellen will lead to heating of the current path. The contacts of portable ThinkPad T42 batteries also suffer if the current flow through the spring contact is too small. Such contacts need to be replaced prematurely. It often appears at the top of the contact small, barely visible craters which have a high resistance to produce or act as an insulator at all. The heat created by a bad contact can cause even melt the plastic of the adapter. Higher voltage at the contacts to improve the flow of current.

Aging ThinkPad T43 batteries with increased resistance and different cells are not suitable for ultra-fast charging, even if they are designed for it. Depth conductivity cells leads to heat generation, which ultimately damages the cells. Keeping the weaker cells, the lower the capacity can be fully charged earlier than the good cells and begin to heat up quickly. Some batteries generate so much heat that the plastic body warms up and can become deformed. A temperature monitoring is essential for rapid and ultra-fast charges.

Different manufacturers offer pulse chargers. By inserting short discharge pulses between each pair Ladeimpulsen the load behavior can be improved. This method promotes the disassembly of oxygen and hydrogen gases, thus lessening the pressure cells, which leads to a lower cell temperature. Pulse chargers are also known for the development of crystal nickel-based vgp-bps8 batteries is reduced (memory) effect. Most of the Cadex battery chargers for nickel-based batteries contain this feature.

Some advanced chargers automatically adjust the charge current depending on the ability of the battery to include any other charge. An empty Latitude D630 battery is expected to start as a very high charge current. Towards the end of charging, the charging current is increasingly reduced. In older batteries will then take into account the possibilities and the charging takes place automatically according to battery characteristics.

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The temperature affection for different battery

March 3rd, 2010

The temperature affection for different battery

Nickel-metal hydrides are less tolerant than nickel-cadmium in terms of the charge at low or high temperatures.

Nickel-metal-hydride can not load quickly at temperatures below 10 ° C, nor can they load slowly below 0 ° C. Some chargers are designed so that they Ladekoeffizienten and the ambient temperature change. Price considerations are not allowed to provide Apple PowerBook G4 12 inch Battery battery chargers for consumer electronics with temperature sensors.

At higher temperatures, the charge acceptance of nickel-based Apple PowerBook G4 Battery is drastically reduced. A battery that can hold at room temperature, a medium capacity of 100%, starts at 45 ° C ambient temperature, only 70%, and even only 45% at a temperature of 60 ° C. This highlights the poor performance of some car chargers in the summer!

Lithium-ion Apple PowerBook G4 15 inch (aluminum) Battery provide a good charging in to deep as well at high temperatures. Some cells allow charging with 1.0 C from 0 ° C to 45 ° C. Most lithium-ion cells, however, prefer a lower charge current when the temperature at 5 ° C or falls below. Must be dispensed on the loading below the freezing point, as a coating can be effected by lithium metal.

The lead-acid Apple PowerBook G4 17 inch Battery is not very sensitive to extreme temperatures, as we all know, on the basis of experience with our car batteries. Part of this tolerance is the inertia of lead-acid systems are attributed. Some battery models allow a shop below the freezing point with a small charging current, while others are damaged, and provide only reduced capacitance values, and life expectancy is shortened.

To improve the loading performance of lead-acid Apple PowerBook G4 17 inch Battery at low temperatures and prevent thermal effects during the warm-up, it is important to monitor the charging voltage limits to be set. An installation of this measure can extend the life expectancy of a battery up to 15%. General guidelines recommend making a correction of about 3mV per cell per degree Celsius. The voltage correction has a negative coefficient, ie The threshold voltage decreases when the temperature rises.

Heat kills the Apple MacBook Pro 17 inch Battery! The warmer the cells shorten, the life expectancy. Higher temperatures may not always be foreseen, especially during a fast charge. It must, however, attempt to keep these periods as short as possible. While 45 ° C is temporarily tolerable, begin a battery from 50 ° C damage is increasing. Moreover, cells are warmer in the interior of a battery, always a few degrees when the temperature of the battery case.

Ultra Fast Chargers

Some manufacturers of chargers promise amazingly short loading time of 30 minutes or less. With well-balanced cells and moderate temperature can nickel-cadmium VGP-BPS10 s batteries, which are designed for fast charging, are being charged in a very short time. This is achieved with a simple increase of the charging current during the first 70% of the charge cycle.

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The temperature and battery charging

March 1st, 2010

Charging at high and low temperatures

Rechargeable laptop battery operate in a reasonably wide temperature range. However, this does not automatically allow a charge in the same temperature range. While the use of batteries in hot or cold environment can not be avoided, the users, the conditions during the load somewhat under control. The charge should be strictly carried out at moderate temperatures.

In general, older battery technologies, such as Nickel-cadmium, tolerant loading at extreme temperatures. Nickel-cadmium Apple A1045 Apple A1061 batteries can be recharged with a quick charge within approximately 1 hours. Such a fast charging should be done within the temperature range from 5 ° to 45 ° C. An even narrower temperature range from 10 ° to 25 ° C, however, yields better results.

Charging below 5 ° C caused a reduced Ladekoeffizienten of 0.1 C (one tenth of the capacity). This is in the area where oxygen and hydrogen inside the cell can be reduced. Due to the declining settings at lower temperatures, leading to a too fast charging excessive cell pressure, which can lead to a Zellenleck. Such a Apple A1148 Apple A1175 battery can be charged under these conditions fully before.

Industrial Apple iBook G4 12 inch Battery that require rapid charging at low temperatures, include a thermal circuit to keep the battery in a temperature range to be allowed. As soon as the charging temperature is lower than is produced during the loading process gas, which in turn leads to a warming, and thus improve the loading conditions. The ideal charger automatically adjusts itself so that there is a balance between gas and charging.

Nickel-metal hydrides are less tolerant than nickel-cadmium in terms of the charge at low or high temperatures. Nickel-metal-hydride can not load quickly at temperatures below 10 ° C, nor can they load slowly below 0 ° C. Some chargers are designed so that they Ladekoeffizienten and the ambient temperature change. Price considerations are not allowed to provide Apple PowerBook G4 12 inch Battery battery chargers for consumer electronics with temperature sensors.

At higher temperatures, the charge acceptance of nickel-based Apple PowerBook G4 Battery is drastically reduced. A battery that can hold at room temperature, a medium capacity of 100%, starts at 45 ° C ambient temperature, only 70%, and even only 45% at a temperature of 60 ° C. This highlights the poor performance of some car chargers in the summer!

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The life of lithium batteries may be extended : temperature

February 22nd, 2010

The life of lithium batteries may be extended : temperature

A lithium-ion battery is 300-500 discharge / charge cycles total. The laptop battery prefers partial discharges rather than full discharges. Frequent full discharges should be avoided whenever possible. In contrast, the battery should be recharged more frequently, or use a larger battery. The memory effect is not an issue, even if carried out unscheduled charges.

Although lithium-ion batteries do not suffer performance losses because of the memory effect, show powerbook g4 battery with a built-in fuel gauge one of engineers known as “digital memory”. This is the reason: Short discharges with appropriate charges will not yield the periodic calibration needed to synchronize the fuel gauge with battery level.

A purposely conducted full discharge followed by recharging after 30 charges corrects this problem. Downloading the inspiron 6400 battery until the shutoff of the device meets this criterion. If this is ignored, the fuel gauge is crucial unreliable. (Find out more in ‘Choosing the right battery for portable computers’, Part Two).

Aging of lithium-ion batteries is an issue that is often neglected. Lithium-based inspiron 6000 battery have a life expectancy of 2 to 3 years. The clock starts ticking as soon as the battery leaves the factory. The capacity loss is already reflected by a higher internal resistance caused by oxidation. Finally, the cell resistance reaches a point where he can give the stored energy is no longer, even if the battery is fully charged.

The increase in internal resistance also applies to lithium-ion batteries with cobalt-based, a chemical which is used in laptops and cell phones used. A smaller energy density lithium-ion vgp bps2c vgp bps2a batteries based on manganese, which is also known as spinel battery that holds in the internal resistance in a lifetime, but loses capacity due to the chemical decomposition.

The speed of aging of lithium-ion batteries is determined by the temperature and charge state. Figure 1 shows the capacity loss as a function of these two parameters.

Figure 1: Permanent capacity loss of lithium-ion pa3399u 2brs pa3465u-1brs batteries as a function of emperature and charge state.
High charge levels and high temperatures accelerate the permanent loss of capacity. Chemical improvements have the benefits of stored lithium-ion batteries increases.

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