Battery power/ inverter(s) running computers. HELP!

Welcome to the forum PrpleButerfly.

Lots of questions... Hang on for a bit of math. Using your numbers:

TV: 1.1 amps * 120 VAC = 120 Watts
Computer: 1.6 amps * 120 volts = 192 Watts
Monitor: 1.5 amps * 120 volts = 180 Watts
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492 Watts total of 120 VAC Power
4.1 amps @ 120 VAC

First problem, if this is reading from the labels on the back of the units--They can be dramatically different vs real life measurements. You really need to make your own measurements under your operating conditions.

One easy way to do this is get a Kill-a-Watt or similar type meter (local hardware store, sometimes even a library will have them for check out).

Next--Picking Energy Star rated devices, Modern LED TV's can use 1/3 or less energy. And a modern laptop can use 20-30 Watts (computer+monitor) vs the 120 Watts (possible) for a desk top computer.

Some quick estimates of the power usage math--First, what is "all day for you"? I will use 10 hours--But that is another choice you will have to make.

• 492 Watts total * 1/0.85 AC inverter eff * 1/12 volt battery bank * 10 hours usage = 482 AH @ 12 volt

Your battery is (I guess) around 125 Amp*Hours @ 12 volts--And for lead acid batteries, you would normally not discharge a deep cycle battery by more than 50% (for longer battery life).

• Suggested battery: 482 AH * 1/0.50 max discharge = 964 AH @ 12 volt nominal battery bank
• Your battery: 964 AH / 125 AH your battery = 7.7 ~ 8 of your batteries

We do a lot of the calculations for power and energy here in "Watts" and Watt*Hours vs Amps and Amp*Hours.... Watts is a "total energy unit vs Amp*Hours--Which is "missing" the voltage for energy calculations.

For example, your devices draw ~4.1 amps at 120 VAC... But draw ~41 amps (or a bit more) at ~12 volts DC.

Before I start throwing a bunch of math at you--Let me know how you would like to proceed. As you can see, even a "nominal" amount of energy usage turns into a big/expensive battery bank pretty quicly--And we have not even discussed how to properly recharge such a battery bank (or even how to choose the "right" batteries for your project--Which does vary based on the size of your project).

-Bill