Battery Indicator - Batteries Not Part of A System

Batteries Not Part of A System

Batteries that are part of a system, such as computer batteries, can have their properties checked and logged in operation to assist in determining remaining charge. A real battery can be modeled as an ideal battery with a specified EMF, in series with an internal resistance. As a battery discharges, the EMF may drop or the internal resistance increase; in many cases the EMF remains more or less constant during most of the discharge, with the voltage drop across the internal resistance determining the voltage supplied. Determining the charge remaining in many battery types not connected to a system that monitors battery use is not reliably possible with a voltmeter. In battery types where EMF remains approximately constant during discharge, but resistance increases, voltage across battery terminals is not a good indicator of capacity. A meter such as an equivalent series resistance meter (ESR meter) normally used for measuring the ESR of electrolytic capacitors can be used to evaluate internal resistance. ESR meters fitted with protective diodes cannot be used, a battery will simply destroy the diodes and damage itself. An ESR meter known not to have diode protection will give a reading of internal resistance for a rechargeable or non-rechargeable battery of any size down to the smallest button cells which gives an indication of the state of charge. To use it, measurements on fully charged and fully discharged batteries of the same type can be used to determine resistances associated with those states.

The cost of an ESR meter makes it uneconomic for measuring battery voltages as its only function, but a meter used for cheeking capacitors can take on the additional duty.

Read more about this topic:  Battery Indicator

Famous quotes containing the words batteries, part and/or system:

    Postmodernism is, almost by definition, a transitional cusp of social, cultural, economic and ideological history when modernism’s high-minded principles and preoccupations have ceased to function, but before they have been replaced with a totally new system of values. It represents a moment of suspension before the batteries are recharged for the new millennium, an acknowledgment that preceding the future is a strange and hybrid interregnum that might be called the last gasp of the past.
    Gilbert Adair, British author, critic. Sunday Times: Books (London, April 21, 1991)

    We are these people,
    wistful, ironical, wilful,
    who have no part in
    new-world reconstruction,
    in the confederacy of labour.
    Hilda Doolittle (1886–1961)

    I have no concern with any economic criticisms of the communist system; I cannot enquire into whether the abolition of private property is expedient or advantageous. But I am able to recognize that the psychological premises on which the system is based are an untenable illusion. In abolishing private property we deprive the human love of aggression of one of its instruments ... but we have in no way altered the differences in power and influence which are misused by aggressiveness.
    Sigmund Freud (1856–1939)