How to measure the internal resistance of a battery?

Apr 15

adminBattery technology, Digital camera review, laptop Comments Off

There are several techniques for measuring the internal resistance of a Ibm thinkpad r50 series battery , each giving slightly different results. One common method is the load test by which the DC current is applied to discharge the battery while measuring the voltage drop. The voltage divided by the current gives the internal resistance.

The CA method, also known under the term conductivity test, measures the electrochemical characteristics of a battery by applying an alternating current. The corrosion of the battery and other conditions contributing to the loss of capacity, alter the conductivity of the battery meter that can read.

Cadex uses a proprietary method for measuring the pulse of the Ibm thinkpad r50e battery internal resistance. Analyzers battery Cadex 7000 Series (Figure 7), we apply a number of pulses of charge and discharge calculating the internal resistance of the battery, according to voltage deviations. Known as the OhmTest, reading mO is obtained in five seconds without discharging the battery. The OhmTest can perform tests on a bulk quantity of batteries, a technique that is useful to vendors of cellular phones to monitor the performance of the battery before selling it. Return on security can also be checked in large part.

However, it is noted that the OhmTest gives no real conclusion about the charge status and health status of the hp pavilion dv6000 battery . The reading can vary greatly and mO is the chemical composition of the battery, the size of the cell (mAh rate), the type of item, the number of elements connected in series, and the kind of son contacts used. It is essential to have good connections to the terminal because a poor contact will give a high reading. Alligator clips and son connection is too long to avoid. A battery must have a load of at least 50% to obtain a reading mOhm significant.

Figure 1:Cadex battery analyzer 7400. The battery analyzers Series 7000 Cadex measure the internal resistance of the battery. MO readings can be made using a 5-second test on the battery or can be included in the maintenance program.

For best results, it is recommended to measure a good Ibm thinkpad r50p battery whose performance is known and use this reading as reference. A reading of mO is required for each battery. The following numbers can be used as reference for digital cellular phones:

* 150 or less per 3.6 V excellent

* 150 to 250 mO by 3.6 V good

* 250 to 350 mO by marginal 3.6V

* 350 to 500 mO by 3.6 V low

* More than 500 mO by 3.6V failure

It should be noted that the battery voltage is mentioned in relation to the reading of milliohms. A cell phone runs on electricity, which means that as the battery voltage, the greater the power requirements are reduced. In theory, a 7.2 volt battery can hold twice the reading mO a battery pack 3.6 volts, because it draws only half the current for the same power.

The OhmTest seems to work better with Li-ion, because the performance degradation is associated with corrosion of the internal element that corresponds to a high internal resistance. The performance of NiMH batteries can also be identified in large part, but the NiCd battery does not lend itself well to the test mOhm.

A low reading mO does not necessarily guarantee a high yield of the NiCd battery. Unlike the Li-ion, NiCd a high internal resistance can often be restored using the program of rehabilitation of a battery analyzer series 7000 Cadex, because the problem may be caused by memory. A successful rehabilitation is known to lower the reading mO by a factor of two or three. The complete restoration of the battery regularly.

Summary

Consumer demands have forced manufacturers to equip mobile phones battery to extend the possible duration of the conversation. However, adding more energy to a battery pack, other qualities have been neglected, especially its durability.

The family of a NiCd battery provides long service life and as might be expected, a low reading of mO. Unfortunately, this chemical composition is more popular for mobile phones because of its moderate energy density. In addition, negative publicity about the phenomenon of memory and a desire to metal toxicity have prompted customers to make other choices.

The battery is the item most expensive cell phone and the only element that is often lacking during the lifetime of the product. It is therefore prudent that manufacturers rely on the link that requires the most attention, including the battery.

About the author

Isidor Buchmann is the founder and CEO of Cadex Electronics Inc.., Richmond (Vancouver) British Columbia, Canada. Mr. Buchmann has received training in radio communications and has studied the behavior of rechargeable batteries for two decades in practice in everyday applications. Author of numerous articles and several books on battery maintenance technology, Mr. Buchmann is a well known speaker who has written technical reports and has made presentations at seminars and conferences worldwide.

About the company

Cadex Electronics Inc.. is a world leader in the field of design and manufacture of analyzers and battery chargers modern. Its successful products are used to prolong Dell xps m1730 battery life in the areas of wireless communications, emergency services, laptop computers, avionics, biochemistry, broadcasting and defense. Cadex products are sold in over 100 countries.

Tips to maximize battery run-time

Apr 02

adminBattery News Comments Off

Netbook users are much more than PC users, so for them the power consumption of the equipment and the stamina of the Batteries so important. If an outlet is close by and you work too long or surfing, it can quickly become too dark for a short duration on the screen. How can something this time herauszögern further, the magazine colleagues tested the laptop and have come to interesting results. The extent to which Reviews are feasible even for one depends on the tolerance but from opposite reading comfort and system performance. The tests were unfortunately not with a Netbook, but with a Toshiba Satellite M505 with Intel Core performed i3, whose normal Ibm thinkpad t400 battery life of 3 hours and 11 minutes was.

The processor offers little potential for power saving

The Dell inspiron 6000 battery consumption of the processor can not further reduce the test that. In the menu Settings -> CPU can minimize the performance, but takes a slower processing speed – in the test than 25 percent – and is still buying in even less power than three minutes duration.

Were tested three more opportunities for power from Ibm thinkpad r50p battery saving, which were much more successful in the execution. The best known version is probably the trick with the screen lighting. This can be from 40 percent in energy saving mode to reduce to 0 percent, or off entirely. Still, the ads are still readable. With the light trick the testers gained in using the M505 eleven minutes longer useful life.

Less light brings the most

Even more efficient in terms of energy makes to the OS Windows 7 disabling the graphical effects. Switching off the enhanced graphics Aero Glass – but the Starter Edition to most netbooks anyway does not exist – and the display mode from Aero Peek, one can work 19 minutes longer. However, with disabling drop off some attractive features and the surface looks more like Windows XP than in Windows.

Most of time the mobile work could win with the last trick. By a simple trick can reduce the light pixels displayed on the screen. Personalized the representation so that the contrast reversed and therefore as many areas are displayed in black instead of white. Thus, the Ibm thinkpad a30 battery could survive in the test 25 minutes longer. Here, too, must respond to compromises, because reading white text on black background is at least used to. The conversion is done by right-clicking on the desktop. It is then necessary to change the design to Windows Classic, only then will the opportunity to select Contrast Black. Here, the features of Aero Glass and Aero Peek go right with flutes and the design is, of course, kind words, very old school.

Sorry, no addition of the effects

All add up the savings along the way, not time gains, but would also even at 19 minutes. Most efficient is to focus on the contrast setting. On the tips of the laptop magazine out there are still other ways too familiar. That is about how to disable WLAN, Bluetooth and UMTSIf this is not needed. Even USB drives and memory cards should be deducted, if not just access it needs. Unnecessary services and processes in the background can also be turned off. And it saves the most electricity from Ibm thinkpad r50 series battery in the rest, if instead of 15 minutes surfing the Internet procrastination time reading a newspaper or something just looks out the window.