Battery Selection
Selecting Battery Type
Select a battery or system of batteries that will provide your APS with proper DC voltage and an adequate amp hour capacity.* Select ‘Deep-Cycle’ batteries to enjoy optimum performance from your APS. Batteries of either Wet-Cell (vented) or Gel-Cell/Absorbed Glass Mat (sealed) construction are ideal. 6 Volt “golf-cart,” Marine Deep-Cycle or 8D Deep-Cycle batteries are also acceptable.**
*Even though APS models are high-efficiency converters of electricity, their rated output capacities are limited by the amp- hour size of the external batteries. ** You must set Configuration DIP Switch #1, Group A (Battery Type) to match the type of batteries you connect or your batteries may be degraded or damaged over an extended period of time. See "Configura- tion," page 5 for more information.
Selecting Battery Amp Hour Capacity
Step 1:
Add the Wattage Ratings of your connected equipment to determine the Total Wattage Required.*
Step 2:
Divide the Total Wattage Required (from Step 1) by the battery voltage to determine the DC Amperes Required.
Step 3:
Multiply the DC Amperes Required (from Step 2) by the number of hours you estimate will pass without AC power before your battery can recharge to determine a Battery Amp-Hours Required Rough Estimate.
Step 4:
Compensate for inefficiency by multipling your Battery Amp-Hour Required Rough Estimate (from Step 3) by 1.2 to determine how many amp-hours of battery backup (from one or several batteries) you should connect to your APS.** Note that the Amp-Hour ratings of batteries are usually given for a 20 hour discharge rate. Actual Amp-Hour capacities are less when batteries are discharged at faster rates: batteries discharged in 55 minutes provide only about 50% of their listed Amp-Hour ratings, while batteries discharged in 9 minutes provide as little as 30% of their Amp-Hour ratings.
Example: A park ranger wants to be able to power two 75-watt transmitters off of 12V batteries for up to an hour after an AC power outage. She divides the total wattage of her equipment (150 watts) by the voltage of the batteries she's using (12V) and multiplies by 1 hour to get a Battery Amp-Hours Required Rough Estimate of 12.5. She multiplies this by 1.2 (for inefficiency) and divides by 50% (since a battery that discharges in an hour only provides about 50% of its stated amp- hour capacity) and determines that her 12V batteries' amp-hour capacities must add up to at least 30.
*The wattage rating is usually stated in the equipment's manuals or on their nameplates. If your equipment is rated in amperes, convert to watts by multiplying its ampere rating by its input voltage (208 or 240). ** Your charging amps multiplied by the charging hours must exceed the discharge amp-hours taken from the batteries between charges or you will eventually run down your battery bank.
Permanent Mounting (Optional*)
(See Diagram 2, p. 33).
•Install two 8 mm (1/4 in.) fasteners* into a rigid horizontal surface using the measurements in the diagram. (Leave the heads of fasteners raised slightly above the horizontal surface in order to engage the slots in the APS's two front feet.)
•Slide APS forward to fully engage the fasteners in the APS's front feet. Install two 8 mm (1/4 in.) fasteners in the APS's two rear feet. Tighten the rear screws to permanently hold your APS in position.
*Recommended for vehicular installation and other applications requiring permanent, secure mounting. All fasteners are user-supplied. Turn your APS OFF and disconnect it from both batteries and AC power before mounting.
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