7
Application Guide
540 watts ÷ 12V =
45 DC Amps
45 DC Amps × 5 Hrs. Runtime
× 1.2 =
270 Amp-Hours
Match Battery Amp-Hour Capacity to Your Application
Select a battery or system of batteries that will provide your Inverter with proper DC voltage and an adequate amp-hour
capacity to power your application. Even though Tripp Lite Inverters are highly-efficient at DC-to-AC inversion, their rated
output capacities are limited by the total amp-hour capacity of connected batteries and the support of your vehicle’s
alternator if the engine is kept running.
• STEP 1: Determine Total Wattage Required
Add the wattage ratings of all equipment you will connect
to your Inverter. Wattage ratings are usually listed in
equipment manuals or on nameplates. If your equipment
is rated in amps, multiply that number times AC utility
voltage to determine watts.(Example: a ¼ in. drill
requires 2½ amps. 2½ amps × 120 volts = 300 watts .)
Note:
Your Inverter will operate at higher efficiencies at about
75% - 80% of nameplate rating.
• STEP 2: Determine DC Battery Amps Required
Divide the total wattage required (from step 1, above)
by the battery voltage (12) to determine the DC amps
required.
• STEP3: Estimate Battery Amp-Hours Required (for
operation unsupported by the alternator)
Multiply the DC amps required (from step 2, above)
by the number of hours you estimate you will operate
your equipment exclusively from battery power before
you have to recharge your batteries. Compensate for
inefficiency by multiplying this number by 1.2. This will
give you a rough estimate of how many amp-hours of
battery power (from one or several batteries) you should
connect to your Inverter.
Note:
Battery amp-hour ratings are usually given for a 20-hour
discharge rate. Actual amp-hour capacities are less when
batteries are discharged at faster rates. For example, batteries
discharged in 55 minutes provide only 50% of their listed amp-
hour ratings, while batteries discharged in 9 minutes provide
as little as 30% of their amp-hour ratings.
300W
+
220W
+
20W
=
540W
¼" Drill
Orbital Sander
Cordless Tool
Charger
300W
+
140W
+
100W
=
540W
Blender
Color TV
Laptop
Computer
Appliances
Example
Tools
