lithium button coin battery

electronics green multimedia machine motherboard lithium button battery battery-backed electronic devices batteries maintain volatile memory powered volts coin batterybattery-backed eprom feeding main-boards upgrade update configuration real-time-clock fixing equipment closeup maintenance data technical watch-batteries storage-condition cr2025 cr2032 electronics computing test ampere 3-volt non-rechargeable manganese-dioxide-battery voltage background cpu electrical engineering button-battery button-cells lithium coin-cell-battery mainboard cell microchip electronic circuit chip board bios full-battery empty-battery energy voltmeter multi-meter memory long-lasting testing test-probes firmware