Battery Selection, Appliances, Watts ÷ 12V =

Battery Selection

Match Battery Amp-Hour Capacity to Your Application

Select a battery or system of batteries that will provide your Inverter/Charger with proper DC voltage and an adequate amp-hour capacity to power your application. Even though Tripp Lite Inverter/Chargers are highly efficient at DC-to-AC inversion, their rated output capacities are limited by the total amp- hour capacity of connected batteries plus the output of an alternator when one is used.

•STEP 1) Determine Total Wattage Required Add the wattage ratings of all equipment you will connect to your Inverter/Charger. 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 estimate watts. (Example: a ¼ in. drill requires 2½ amps. 2½ amps × 120 volts = 300 watts.)

NOTE: Your Inverter/Charger will operate at higher efficiencies at about 75% - 80% of nameplate rating.

		Example
		Tools
¼" Drill		Orbital Sander		Cordless Tool
¼" Drill		Orbital Sander		Charger
				Charger
300W	+	220W	+	20W	= 540W

Appliances

Blender

Color TV

Laptop Computer

300W + 140W + 100W = 540W

• STEP 2) Determine DC Battery Amps Required

Divide the total wattage required (from step 1, above) by the battery voltage to determine the DC amps required.

• STEP 3) Estimate Battery Amp-Hours Required

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 with utility- or generator-supplied AC power. 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/Charger.

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.

540 watts ÷ 12V =

45 DC Amps

45 DC Amps ×

2 Hrs. Runtime ×

1.2Inefficiency Rating = 108 Amp-Hours

•STEP 4) Estimate Battery Recharge Required, Given Your Application

You must allow your batteries to recharge long enough to replace the charge lost during inverter operation or else you will eventually run down your batteries. To estimate the minimum amount of time you need to recharge your batteries given your application, divide your required battery amp-hours (from step 3, above) by your Inverter/Charger’s rated charging amps (see Specifications section).

NOTE: For Tripp Lite Inverter/Chargers providing 1000 watts or less of continuous AC power, a full-size battery will normally allow sufficient power for many applications before recharging is necessary. For mobile applications, if a single battery is continuously fed by an alternator at high idle or faster, then recharging from utility or generator power may not be necessary. Tripp Lite Inverter/Chargers will provide adequate power for ordinary usage within limited times without the assistance of utility or generator power. However, when operating extremely heavy electrical loads at their peak in the absence of utility power, you may wish to “assist your batteries” by running an auxiliary generator or vehicle engine, and doing so at faster than normal idling.

Tripp Lite APS700HF Battery Selection, Match Battery Amp-Hour Capacity to Your Application