Voltage under load

We perform work whenever we connect the two poles of the battery across a load. The Toad in this respect might be a torch, calculator, car, phone or watch - anything which causes a current to pass. And this flow of current causes the voltage across the battery or cell to decrease see Figure 7.4. We call this voltage the voltage under load . 

Ohm s law, Equation (7.16), describes the difference between the emf and a voltage under load ... 

Charge/discharge cycle characteristics for a cell operating at room temperature are shown in Fig. 6.21. The high cell voltage under load (> 1.5 V even at a rate of 2 C) is noteworthy. 

Cell voltage under load eurrent (A/cm) is expressed as (Hirschenhofer et al, 1998) ... 

Its accuracy was then compared with the SoC calculated with data from voltage under load (VUL), open circuit voltage (OCV) and fixed frequency impedance (FFI). 

Figure 1. SoC-error matrices for voltage under load (1st row), open circuit voltage (2nd row) and 100 mHz fixed frequency impedance (3rd row). Results for the LFP cell are displayed in the left, NCM in the right column. Scales show the absolute deviation between calculated SoC and that determined by...

The cell voltage under load, the closed circuit voltage (CCV), depends on the current, the state of charge, and on the cell s history, like its hfetime or storage period. 

Figure 3.12 Fuel cell voltages and current levels as a function of various parameters involved. (AS reaction entropy T temperature electrolyte resistance ff- thermal cell voltage P thermodynamic cell voltage f cell voltage under load i load current tj overvoltage at the electrodes n number of cells f configuration factor.)...

Nominal voltage under load Plateau voltage regulation at fixed load and 5°C Cycle life (dependent on model and usage conditions) typical life to 80% cf nominal... 

Nominal voltage under load Plateau voltage regulations Recommended discharge cut-off voltage... 

Honeywell have recently developed a high-integrity erimp-sealed lithium-vanadium pentoxide button cell. This has an open-circuit voltage of 3.42 V and a voltage under load of more than 3V. The G3093 model has a rated eapacity of 300mA h and the G3094... 

Initial voltage (voltage under load after 2 mA h have been removed 1.32 V... 

Average voltage (voltage under load at mid-life, after 10 mA h have 1.22 V... 

Table 36.1 Typical applications, load, voltage under load and amperage reading for testing cf the most widely used carbon-zinc Leclanche cells and batteries...

ANSI designation Application Load ( ) Voltage under load (% of applied voltage shown on cell or battery label Amperage (A) for usable cell or battery (test for an instant only)... 

Nominal voltage under load Voltage regulation... 

Figure 56.21 Projected performance of Catalyst Research Corporation Lithiode TM lithium-iodine cells based on 5 years test data, (a) Voltage under 190kn load, (b) voltage under load (Courtesyof Catalyst Research Corporation)...

To predict the local polarisation in a full-scale cell or stack at any point, its dependence on composition, pressure, and temperature of the gas flowing in the gas channel contacting the electrode must be known. In a large cell, these bulk gas properties vary from one point to the next. Electrode polarisation or overpotential - the difference between the local potential of the electrode under load and the potential at open circuit (equilibrium potential) - is also a local quantity because it depends not only on the bulk gas composition but also on the current density. In a large cell the current is usually distributed nonuniformly, as discussed in Sections 11.2-11.5. Similar to Eq. 7, one can express the local cell voltage under load, i.e., when current is passed, as the thermodynamic cell potential minus three loss terms the ohmic loss, the cathode polarisation, and the anode polarisation ... 

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