Batteries in Circuits
Discussion
introduction
series: add voltges. A battery is a series of cells.
parallel: add currents — sort of. This is not a good way to store batteries, by the way.
internal resistance
V = ℰ − Ir
where…
| V = | terminal voltage, the voltage that you actually get out of the battery under operating conditions, the voltage that you'd measure across the terminals |
| ℰ = | electromotive force (emf), the ideal voltage of the battery, the electic potential difference caused by the chemical reaction taking place inthe battery, a number that chemists learn to compute |
| I = | current, the load that the battery is delivering to the circuit |
| r = | internal resistance, every part in a circuit has some resistance — even batteries, which are normally thought of as pure voltage elements |