Abstract: A voltage controlled display is described. The voltage controlled display is a low voltage display and has a display element having a pair of electrodes and a voltage divider having a terminal coupled to a first one of the pair of electrodes of the voltage controlled display. A metal-insulator-metal diode having a switching voltage less than about 10 volts coupled to the voltage divider. In a preferred embodiment, the display element further includes a second metal-insulator-metal device and wherein the voltage divider includes a resistor coupled in series with the second metal-insulator-metal diode.

Abstract: A battery includes a cell having an outer circumference and a battery tester. The batter tester can be of different types. One type a segmented display tester includes a first voltage divider and a plurality of parallel battery tester elements including a voltage controlled display having a first terminal coupled to the first voltage divider and a second voltage divider coupled in parallel with the first voltage divider and coupled to a second terminal of the voltage controlled display. The second voltage divider also includes a non-linear device. A second type of battery tester is also disclosed. This type is a variable type and has a first voltage divider including a non-linear device coupled to a plurality of resistance elements and a voltage controlled display having a first terminal coupled to the first voltage divider and a plurality of second terminals coupled to the plurality of resistance elements.

Abstract: A battery includes a battery tester including a display that is disposed around a substantial portion of the circumference of the battery. Also describe is a battery operated electronic device including a case that houses electronic components that comprise the electronic device, said case including a door that opens up to a battery compartment, with the door having at least a transparent window portion in the door.