myecpro-laptop battery

To better understand the automatic battery conditioning system in the FEH, here is something I put together with the help of the Ford patent on this issue. There have been many post regarding strange behavior while driving the FEH, and many times it’s normal and caused by the DELL laptop battery conditioning system.

The TBCM (Traction Battery Control Module), controls charging and/or discharging of an HEV battery, in response to battery life and/or performance degrading events, or battery maintenance conditions. The TBCM monitors for four battery life and/or performance degrading events dell Inspiron 700m battery,dell Inspiron 710m battery.
First, the TBCM determines if the battery needs to be charged to reverse deactivation. Deactivation is caused by prolonged duration of idle time at low state of charge (SOC). Deactivation results in reduced ability to accept charge.
Second, the TBCM determines if the battery needs to be refreshed to reverse memory effect. Memory effect is caused by repeated shallow discharging and recharging, or cycling, of the battery. Memory effect causes a loss of storage capacity.
Third, the TBCM determines if the battery needs rebalancing. The typical HEV battery, like the battery, is constructed from cells or modules that are coupled together to provide the desired voltage. A typical HEV battery may have as many as 240 modules. The modules of the battery will have different performance characteristics based on manufacturing differences, module age and module temperature, for example. If a module that has diminished charge capacity is overcharged, this can lead to module failure dell Inspiron 8500 battery,dell Inspiron 8600 battery,dell Inspiron 9200 battery.
Fourth, the TBCM determines if the battery needs state of charge reset. A module can be so deeply discharged that the battery reverses. This reversal can adversely affects battery performance, and can cause long-term damage to the module and the circuitry coupled thereto.
While the TBCM monitors the battery for these four battery maintenance conditions, it is not so limited. The TBCM may monitor the battery for other battery life and/or performance degrading events other than those listed above.
Having determined that one of these four conditions exists, the TBCM communicates with the VSC via CAN to determine if the necessary remedial activity can be conducted immediately, or if the activity needs to be delayed to avoid interference with vehicle operations. For example, to refresh the battery to remove memory effect, it may be desirable to deeply discharge and then charge the affected module. It may also be the case that the vehicle is operating in a state or mode where the battery is already in a state of discharge, or the capacity is not available to charge the module. Alternatively, it may be the case that the TBCM, to determine the state of the battery, needs to perform a diagnostic discharge or charge of the module of the battery , which diagnostic discharge or charge may affect vehicle performance. Consequently, the TBCM preferably first determines if the diagnostic or remedial action would compromise the vehicle’s performance by communicating with the VSC and determining a vehicle condition dell Inspiron 9300 battery,dell Inspiron 9400 battery,dell Inspiron B120 battery,dell Inspiron B130 battery.

Some rechargeable batteries can be restored through external means, such as applying a full discharge. There are, however, many defects that cannot be corrected. These include high internal resistance, elevated self-discharge, electrical short, dry-out, plate corrosion and general chemical breakdown.

The performance loss of a battery occurs naturally as part of usage and aging; some is hastened by lack of maintenance, harsh field conditions and poor charging practices. This paper examines the cause of non-correctable battery problems and explores ways to minimize these breakdowns.

High Self-discharge
All dell inspiron 9300 battery are affected by self-discharge. This is not a defect per se, although improper use enhances the condition. Self-discharge is asymptotical; the highest loss occurs right after charge, and then tapers off.

Nickel-based batteries exhibit a relatively high self-discharge. At ambient temperature, a new nickel-cadmium loses about 10% of its capacity in the first 24 hours after charge. The self-discharge settles to about 10% per month afterwards. Higher temperature increases the self-discharge substantially. As a general guideline, the rate of self-discharge doubles with every 10°C (18°F) increase in temperature. The self-discharge of nickel-metal-hydride is about 30% higher than that of nickel-cadmium.

The self-discharge increases after a nickel-based dell inspiron 9400 battery has been cycled for a few hundred times. The battery plates begin to swell and press more firmly against the separator. Metallic dendrites, which are the result of crystalline formation (memory), also increase the self-discharge by marring the separator. Discard a nickel-based battery if the self-discharge reaches 30% in 24 hours

The self-discharge of the lithium-ion battery is 5% in the first 24 hours after charge, and then reduces to 1% to 2% per month thereafter. The safety circuit adds about 3%. High cycle count and aging have little effect on the self-discharge of lithium-based batteries.
A lead-acid dell inspiron b120 battery self-discharges at only 5% per month or 50% per year. Repeated deep cycling increases self-discharge.

The percentage of self-discharge can be measured with a dell inspiron b130 battery analyzer but the procedure takes several hours. Elevated internal battery resistance often reflects in higher internal battery resistance, a parameter that can be measured with an impedance meter or the OhmTest program of the Cadex battery analyzers.

Cell matching
Even with modern manufacturing techniques, the cell capacities cannot be accurately predicted, especially with nickel-based cells. As part of manufacturing, each cell is measured and segregated into categories according to their inherent capacity levels. The high capacity ‘A’ cells are commonly sold for special applications at premium prices; the mid-range ‘B’ cells are used for commercial and industrial applications; and the low-end ‘C’ cells are sold at bargain prices. Cycling will not significantly improve the capacity of the low-end cells. When purchasing rechargeable dell inspiron e1405 battery at a reduced price, the buyer should be prepared to accept lower capacity levels.

The cells in a pack should be matched within +/- 2.5%. Tighter tolerances are required on batteries with high cell count, those delivering high load currents and packs operating at cold temperatures. If only slightly off, the cells in a new pack will adapt to each other after a few charge/discharge cycles. There is a correlation between well-balanced cells and dell inspiron e1505 battery longevity.

Why is cell matching so important? A weak cell holds less dell inspiron e1705 battery capacity and is discharged more quickly than the strong one. This imbalance may cause cell reversal on the weak cell if discharged too low. On charge, the weak cell is ready first and goes into heat-generating overcharge while the stronger cell still accepts charge and remains cool. In both cases, the weak cell is at a disadvantage, making it even weaker and contributing to a more acute cell mismatch.

Quality cells are more consistent in capacity and age more evenly than the lower quality counterparts. Manufacturers of high-end power tools choose high quality cells because of durability under heavy load and temperature extremes. The extra cost pays back on longer lasting packs.

lithium-based cells are by nature closely matched when they come off the manufacturing line. Tight tolerances are important because all cells in a pack must reach the full-charge and end-of-discharge voltage thresholds at a unified time. A built-in protection circuit safeguards against cells that do not follow a normal voltage pattern.

Shorted Cells
Manufacturers are often unable to explain why some cells develop high electrical leakage or an electrical short while still relatively new. The suspected culprit is foreign particles that contaminate the dell latitude d410 battery cells during manufacturing. Another possible cause is rough spots on the plates that damage the separator. Better manufacturing processes have reduced the ‘infant mortality’ rate significantly.

Cell reversal caused by deep discharging also contributes to shorted cells. This may occur if a nickel-based battery is being fully depleted under a heavy load. nickel-cadmium is designed with some reverse voltage protection. A high reverse current, however, will produce a permanent electrical short. Another contributor is marring of the separator through uncontrolled crystalline formation, also known as memory.

Loss of Electrolyte
Although sealed, the cells may lose some electrolyte during their life, especially if venting occurs due to excessive pressure during careless charging. Once venting has occurred, the spring-loaded vent seal on nickel-based cells may never properly close again, resulting in a build-up of white powder around the seal opening. The loss of electrolyte will eventually lower the battery capacity.

Permeation, or loss of electrolyte in valve regulated lead-acid batteries (VRLA) is a recurring problem. Overcharging and operating at high temperatures are the causes. Replenishing lost liquid by adding water offers limited success. Although some capacity may be regained, the performance becomes unreliable.

If correctly charged, lithium-ion cell should never generate gases and cause venting. But in spite of what is said, the lithium-based cells can build up internal pressure under certain conditions. Some cells include an electrical switch that disconnects the current flow if the cell pressure reaches a critical level. Other cells rupture a membrane to release the gases in a controlled way. lithium-ion-polymer dell latitude d420 battery,dell latitude d430 battery in a pouch cell sometime grows to the shape of a small balloon because these cells do not include venting. Ballooning cell are known to damage the housing of the portable device.