what size battery do i need for a 1000w inverter

Battery Size for 1000 Watt Inverter

For a 1000 watt inverter, you'll need at least a 100Ah battery. Anything smaller than this and you will run out of energy very quickly.It is also important to choose the right battery cable.

To understand the best battery size for you, let me explain the factors to consider. Battery sizes are measured in Amp-hours (Ah), this is the total amount of energy they can store.

So all you need to do is find out how much energy your inverter uses per hour to know how long your battery will last.

inverter 1000

If you're wondering how much energy your inverter uses, here's a simple formula to help you figure it out. For this example, we will say your inverter is drawing a full load of 1000 watts. Keep in mind that you likely won't be using that much power all the time, so you can adjust the formula accordingly.

The formula to find your inverter Amps (A) is Watts ÷ Volts = Amps

Drawing 1000 watts from a 12 volt battery would result in this:

1000W ÷ 12V = 83.3A.

At full load, a 1000 watt inverter uses 83 Amps per hour.

So if you're running your inverter at full power for one hour, it will use 83 Amps. If you're only using it for half an hour, it will use half that amount, or 41.5 Amps. And so on.

Keep in mind that this is just a rough estimate - your actual usage may vary depending on factors like the efficiency of your inverter, the power draw of the devices you're running, and so on. But this formula can give you a good starting point for figuring out how much power your inverter uses.


How Much Power Are You Drawing?

If you're going to be running a lot of high-wattage appliances with your inverter, then you'll need to size your battery accordingly. 1000 watts is the maximum output of most inverters, so if you're regularly drawing that much power, you'll need a large battery to support it.

1000 watt inverter

However, if you're only running lower-wattage items like lights and a TV, then you won't need such a large battery. In this case, you can save money and space by sizing your battery to match your actual power needs.

If you only consume 300W,To figure out how long your battery will last, you can use the following formula:
300W ÷ 12V = 25A.
So, a 100Ah battery would last up to 4 hours.
Keep in mind that if you have an appliance that uses more watts than your battery can handle, it will drain the battery more quickly. If you're not sure how many watts your appliance uses, you can get a wattmeter to get exact readings.


1000W Battery Size Inverter Chart

Inverters are a great way to power your devices when you don't have access to a conventional power source. But how long can you actually run your devices with a 12v battery and a 1000 watt inverter?

According to this handy chart, you can expect to get about 4 hours of run time with a lead-acid battery, and 8 hours with a lithium battery. Plus, the difference in voltage between lead-acid and lithium batteries can make a big difference in how long your devices will last.

Runtime 1000 Watts

Runtime 500 Watts

Lead Acid (50% Discharge Capacity)

Lithium (100% Discharge Capacity)

1 hour

2 hours



2 hours

4 hours



5 hours

10 hours



10 hours

20 hours



15 hours

30 hours



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