Devices that were designed to operate using primary alkaline chemistry (or zinc–carbon/chloride) cells may not function with NiMH cells. However, most devices compensate for the voltage drop of an alkaline battery as it discharges down to about 1 volt. Low internal resistance allows NiMH cells to deliver a nearly constant voltage until they are almost completely discharged. Thus battery-level indicators designed to read alkaline cells overstate the remaining charge when used with NiMH cells, as the voltage of alkaline cells decreases steadily during most of the discharge cycle.