This document describes an experiment on charging and discharging of capacitors. It involves using a 100μF capacitor, 1MΩ resistor, 9V battery, and multimeter. The procedure is to connect these components in a circuit and take voltage readings across the capacitor at 20 second intervals as it charges.
Most of the discharge process occurs during this middle portion. During the final stage of discharge, the voltage again drops rapidly. This is referred to as the "knee". Discharging a battery through this portion significantly reduces the number of cycles that the battery can endure and can result in permanent damage to the battery.
The energy capacity vs. discharge rate affects the weight, size, and cost of a battery and device. Amongst others, this information is useful for: Lead acid (PbA) batteries are one of the most widely used types of batteries today. Every automobile has a lead acid battery for starting the engine and powering the electric system.
Charge and discharge curves - Lead-acid batteries have unique charge and discharge curves (voltage vs. time during charging and discharging). Amongst others, these curves can be used for: Understanding the float behavior of lead acid batteries, or how the voltage of a battery changes when a charge or discharge process is stopped.
The next phase of discharging is in the bulk or main part of the discharge. During this phase, most of the energy of the battery is discharged. For a lead acid battery, this happens in a relatively linear manner, with the voltage dropping in proportion to the Depth of Discharge, or inversely proportional to the State of Charge.
For the discharging process, is equal to the time for V(t) to fall 63% from its initial value. These values can actually be measured at any time during the charging or discharging cycle, as long as one waits long enough for the capacitor voltage to increase or decrease by 63% of a measured value.