Monday, July 26, 2010

Discovery Battery Rapid Tests

When I asked a major manufacturer of batteries, "Is it feasible to rapid tests in batteries? " the engineer in a firm tone replied:" No. "His conclusion was based on the difficulty of using a universal testing method applicable to all battery applications, from wireless communications to mobile computing tools power forklifts and electric vehicles (Sony Vaio VGN-FZ battery).

Several universities and companies, including Cadex Electronics, are efforts to find a manageable solution for rapid verification of batteries. They have tried many methods, and some have failed to be inaccurate and impractical (Sony VGP-BPS8 battery).

By studying the characteristics associated with health status and state of charge (SoH and SoC respectively) of the batteries can observe some interesting effects. Unfortunately, these properties are irregular and nonlinear, and worst of all, the parameters are unique for each type of battery. This makes it difficult to create a formula that is applied in all batteries (Sony VGP-BPL9 battery).

Despite these seemingly insurmountable complexity, verification batteries can be quick. But the question one asks is, "What accuracy will have, and how to adapt to chemical compositions permanently changing the batteries (Sony VGP-BPL11 battery)?

The secret of quick checks battery lies in understanding how to use the same energy. The battery charges vary from short current peaks for a digital mobile phone (PCS, GSM), a significant charges intermittent power tools, and food for a constant current laptops.

The first step in obtaining readings quick check is to measure the battery internal resistance, often called impedance. Impedance measurements take only a few seconds and provide a fairly accurate indication of battery condition, especially if you have a baseline reading of a good battery for comparison (Sony VGP-BPL15 battery).

Unfortunately, the impedance measurement provides only a rough idea of battery performance. The readings are affected by different conditions of the battery can not always be controlled. For example, a fully charged battery just out of the charger shows a higher impedance than one that has remained motionless for a few hours after charging. The high impedance noise is due to electro-chemistry that exists after the load. Allowing the battery to rest one or two hours, the normalized (Sony VGN-FZ460E battery). Temperature also affects the readings. In addition, the chemical process, the number of cells connected in series and a battery capacity, influence the results. Many batteries also contain a protection circuit that distorts other readings (Sony VGP-BPS11 battery).

The lithium battery changing

In a recent conversation with a major manufacturer of batteries Lithium-ion, I learned that the chemical processes of change lithium batteries every six months. Will discover new chemical compositions that provide better load characteristics, higher capacity and longer storage life. Although beneficial for users, these improvements make havoc in the battery test equipment, which base their rapid test algorithms set parameters. Let me explain why these changes in the composition of the battery affect the test results with rapid testers (SONY VAIO VGN-FZ4000 Battery).

The first lithium-ion showed a gradual drop in voltage during discharge. With the newer lithium batteries, you can achieve a higher voltage level. These batteries provide a more stable voltage for most of the discharge cycle. The rapid drop in voltage occurs only at the end of the discharge (Sony VGP-BPS10 battery).

A pre-wired test looks for a voltage drop early and estimating SoH fixed according to the knowledge available for reference. If the drop voltage changes due to improved battery technology will result erroneous readings ( Sony VGP-BPS3 battery).

The different metals disturb the positive electrode voltage open terminal. Manganese has a terminal voltage slightly higher compared with the traditional cobalt. In addition, manganese ages differently to cobalt.Although both cobalt and manganese systems belong to the family of Li-ion, is likely to produce differences in the readings when testing a battery quick side by side (Sony VGP-BPS2 battery).

Lithium-polymer has a composition different from lithium-ion and responds differently when testing. The instruments capable of verifying Lithium-ion may not be reliable in its readings when used in rapid tests Lithium-polymer batteries (Sony Vaio VGN-FZ21M battery ).

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