12V 7.2Ah LiFePO4 Battery

The 12V 7.2Ah LiFePO4 battery is a 12.8-volt block of 92.2 watt-hours in the F2-terminal case that alarm and fire panels are built around. The 12V 7Ah battery is the standard backup unit in security and life-safety systems, and this is its lithium form.

The Standby Job

Power that has to be there

An alarm or fire panel keeps a 12V 7Ah battery on float and calls on it the moment mains power drops. NFPA 72 section 10.6.7.2 requires a standard fire alarm system to hold 24 hours of standby and then sound a full 5-minute alarm on battery alone.

Sizing

Reading the calculation

An addressable smoke detector pulls 50 to 375 microamps, a magnetic door holder draws 20 milliamps, and a few dozen of them across a building add up to the tenths of an amp a panel idles at. Take a panel drawing 150 milliamps in standby: over 24 hours that is 3.6 amp-hours, add the notification load for the five-minute alarm, and multiply the total by the 1.25 aging factor NFPA 72 sets for battery derating. A 7.2Ah block covers a panel of that size with room to spare, and its flat discharge holds the panel voltage steady where a fading lead battery would drift toward the low-voltage trouble threshold.

The Panels

Where it goes

Honeywell, DSC, Napco and similar control panels all use this battery size, as do small uninterruptible supplies for routers and access-control heads. A sealed lead battery here lasts three to five years and gets swapped on a schedule whether it has failed or not; this block holds more than 2,500 cycles and floats far longer before it fades, which thins out the replacement rounds a facility runs across its panels.

Backup Runtime

Small UPS duty

Away from the fire panel, this block is the cell in a small uninterruptible supply for a router, an optical network terminal and a security recorder. That cluster draws around an amp at 12 volts, which 92.2 watt-hours carry for roughly seven hours, long enough to hold a home office or a camera feed through a typical grid outage. The units it stands in for are the sealed lead batteries these systems ship with, the CSB GP1272 and Yuasa NP7-12 class rated for three to five years before a scheduled swap.

Data

Datasheet

Fit

Fitment and float

The F2 terminals and the 12V 7Ah footprint match the trays inside alarm cabinets and small UPS units. A panel built for lead floats its battery at 13.6 to 13.8 volts, which this battery tolerates, but a panel that pushes a high float or runs an equalization pulse shortens lithium life, so confirm the float setting before fitting. The internal BMS carries overcharge, over-discharge, overcurrent and low-temperature charge protection, and discharge runs from minus twenty to sixty degrees, so a panel in an unheated riser keeps its backup through a cold night. Store spare batteries at 30 to 50 percent charge.