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5 Battery Considerations
Battery Selection
Given a fixed output power requirement, the operating time that the
Surefire 512 will provide in the absence of electricity, is determined only by
the size and condition of the battery. It is important for the user to select
a deep cycle, sealed, and maintenance free type, such as a marine battery.
Automotive batteries are unsuitable and therefore not recommended.
The condition of a battery is determined by its ability to attain and maintain
a 100% state of charge. In order to measure the state of charge the user
should use a digital voltmeter that can display hundredths of a volt when
measuring 12 Volts. The user should measure battery voltage at the battery
posts, with the battery disconnected. For deep cycle batteries, the following
table relates the State of Charge to Battery Voltage.
6 Installation
6.1 Items Required
Tools:
Philips screw driver, Small slip-joint pliers
Battery:
The user should select a battery with wing nut connections if
possible. (If the user wishes to use a battery with conventional posts, he
should install wing nut adapters.)
6.2 Location
The Surefire 512 can be mounted vertically or horizontally on a flat smooth
surface - wall or floor location
A) Close to 3-prong AC outlet
- within 5 feet.
State of Charge
Battery Voltage
100%
12.7-12.9
80%
12.5-12.6
60%
12.3-12.4
40%
12.1-12.2
20%
11.9-12.0
