Laptop, notbook, tech news

 The main features include battery electromotive force, rated capacity, rated voltage, open circuit voltage, internal resistance, charge-discharge rate, resistance, longevity and self-discharge rate.
Emf
Electromotive force balance between the two electrodes of the electrode potential difference, to lead-acid batteries, for example, E = Ф +0- Ф-0 + RT / F * In (αH2SO4/αH2O).
Where: E-emf
Ф +0- positive standard electrode potential, its value is 1.690
Ф-0-negative standard electrode potential, its value is -0.356
R-universal gas constant, its value is 8.314
T-temperature, and PA3191U-1BRS battery in which the temperature on
F-Faraday constant, its value is 96500
αH2SO4-activity of sulfuric acid, and sulfuric acid concentration of
αH2O-water activity, and the concentration of sulfuric acid
As can be seen from the previous style, the standard lead-acid battery electromotive force for the 1.690-(-0.0.356) = 2.046V, so the battery nominal voltage of 2V. Lead-acid battery electromotive force and temperature and sulfuric acid concentration.
Rated Capacity
In the design requirements of the conditions (such as temperature, discharge rate, termination voltage, etc.), the PA3356U-1BRS battery should be able to release the minimum capacity, in ampere-hours in order to sign C said. Capacity greatly influenced by the discharge rate, so often in the lower right corner of the letter C with Arabic numerals indicate discharge rate, such as the C20 = 50, shows that the capacity under the 20:00 ratio of 50-an-hour. The theoretical capacity of the battery cell reaction according to type of electrode active material usage and calculated according to Faraday’s law of electrochemical active substances derived equivalent accuracy. Since the battery in the side effects that may occur as well as the design of the special needs of the battery’s actual capacity is often less than the theoretical capacity.
Voltage
The battery at room temperature, a typical operating voltage, also known as the nominal voltage. It is the choice of different types of batteries for reference. The actual battery voltage with the different conditions of use vary. The ThinkPad T42 Series battery open circuit voltage is equal to the positive and negative electrodes of the balance of the difference between the electrode potential. Only with the type of electrode active material, but not with the number of active substances has nothing to do. The battery voltage is essentially a DC voltage, but in some special conditions, the electrode reaction caused by the metal crystals, or some of the phase transition into a phase membrane will cause a slight voltage fluctuation, a phenomenon known as noise. Volatility small but very wide frequency range, so the circuit can be distinguished from self-excited noise.
Open-circuit voltage
Battery terminal voltage under open-circuit condition is called open-circuit voltage. Open circuit voltage is equal to the battery when the battery in the circuit (ie there is no current through the bipolar pm) battery positive electrode potential and the anode electrode potential difference. The ThinkPad X60 battery open circuit voltage with V opening, said that the V open = Ф +-Ф-, which Ф +, Ф-positive cells were negative electrode potential. The battery open circuit voltage, generally less than its emf. This is because the two poles of the battery electrolyte solution in the electrode potential established is usually not a balance of electrode potential, but the stability of electrode potentials. Generally similar to that of the open circuit voltage of the battery is the battery EMF.
Resistance
The battery internal resistance is the current through the battery is subject to the internal resistance. It includes the ohmic resistance and polarization resistance, polarization resistance, but also the electrochemical polarization resistance and concentration polarization resistance. Due to the presence of resistance, the battery voltage is always less than the battery emf <IMG src=”http://t12.baidu.com/it/u=2325898283,3451946212&fm=0&gp=10.jpg” name=pn19> or open-circuit voltage. The battery internal resistance is not constant, in the charging and discharging process of change over time (progressively larger), this is because the active substance the composition of the electrolyte concentration and temperature are constantly changing. Ohm’s law Ohm’s resistance to comply with the polarization resistance increases with the current density increased, but not a linear relationship. Often with the current density increased.
Resistance is to decide an important indicator of  ThinkPad T61 battery performance, it directly affects the battery voltage, operating current, the output energy and power, for the battery, its internal resistance as small as possible.
Charge-discharge rate
Sometimes rate and magnification two kinds of representation. Charge and discharge time when the rate is expressed by the charge and discharge rate, numerically equal to the rated battery capacity (ampere-hour) divided by the provisions of the charge and discharge current (An) obtained the number of hours. Magnification is the charge and discharge rate of another representation, the reciprocal of the rate of its value too. The battery discharge rate is based on the original by a fixed resistor to the termination voltage discharge time to that. Discharge rate greater impact on battery performance.
Impedance
Electrodes inside the battery has great – electrolyte interface area, it could be the battery is equivalent to a large capacitance and small resistance, inductance in series circuit. However, the reality is much more complex, in particular, the impedance of the battery and the DC level over time change, the measured impedance is only valid for specific measurement of the state.
Life
Storage life refers to the beginning of the use of the battery is made between the maximum time allowed to store to-year unit. Including the storage period and the use of total duration of that period, including the validity of the battery. Save battery life there is dry storage and wet storage life of life points. Is the  FRU 42T4511 battery cycle life under the specified conditions are met can achieve the maximum charge and discharge cycles. The specified cycle life must also provides charge-discharge cycle test systems, including the charge and discharge rate, discharge depth, and ambient temperature range.
Self-discharge rate
Storage batteries in the process of self-capacitance rate of loss. Save time with the unit of self-discharge accounts for the loss of storage capacity before the capacity expressed as a percentage.
The calculation of the FRU 92P1137 battery
Where E is emf, r for the power supply resistance, internal voltage U in = Ir, E = U, within + U external
Scope: pure resistance circuit
Closed circuit in the energy transformation:
E = U + Ir
EI = UI + I ^ 2R
P release = EI
P output = UI
Pure resistance circuit
P out = I ^ 2R
= E ^ 2R / (R + r) ^ 2
= E ^ 2 / (R ^ 2 +2 r + r ^ 2 / R)
When r = R when the P output maximum, P out = E ^ 2/4r (mean inequality