How Many Batteries for a 700-watt Inverter

A 700-watt power inverter can run a variety of small appliances and electronic devices that operate at or below 700 watts of power consumption. The inverter converts direct current (DC) electricity stored in a battery into alternating current (AC) electricity that can be used to power these appliances and electronics.

The capacity of the battery will determine how much power your inverter can supply and how long it can power an appliance. In this article, we look at what you can run off a 700-watt inverter and what battery to use with the inverter. 

What can you run off a 700-watt Inverter?

A 700-watt inverter is meant to run appliances up to 700-watt max however it can support a continuous output somewhere around 600 watts. This is because of efficiency and conversion losses. Operating at 600 watts also ensures that the inverter is not overloaded. 

A 700-watt inverter can run the following:

Small appliances like a 400-watt blender and a 500-watt coffee maker. 

Small power tools such as drills, saws, and sanders. 

Refrigerator: A 200-watt refrigerator with a 400-watt surge. 

Blender: A 400-watt blender

Computer: A 200-300-watt desktop computer. 

It can also run several other devices including lights, laptops, mini-fan, phones, and TV. 

The actual runtime of the devices will depend on the capacity of the battery and the power requirements of the device being used. While even getting a bigger Inverter might run more appliances this still depends on the battery used.

Let’s look at what size of battery you’ll need. 

How Battery Size for a 700-Watt Inverter?

The battery size for a 700-watt inverter will depend on several factors, such as the power requirements of the devices, expected runtime, and voltage of the inverter. 

To determine the size of the battery we need first to determine the amp drawn from the inverter. 

How Many Amps Does a 700-watt Inverter Draw?

To calculate the amps required you divide the Watts by the voltage. The voltage in a battery bank is usually between 12v and 24v depending on how you wire the system. This is what is referred to as the input voltage. 

To find the amps of the battery, you divide the watts by the voltage. 

For a 12v system, you’ll need 

700/12 = 58.33 Amps 

A 12-volt 700-watt should have a battery that can safely provide up to 58.33 amps of current. 

For a 24v system, you’ll need 

700/24 = 29.16 Amps 

How many Amp-hours will you need?

Deep cycle batteries are recommended to be discharged at 0.2C or at 20% capacity. For 58 amps, you’ll need a 12v battery that is at least 300Ah, and for 30 amps you’ll need a 150Ah 24v for 24v battery bank. 

For lithium batteries that can be discharged up to 50% of their capacity, you can use a 75Ah 24v battery and 120Ah 12v battery to provide 1400 Watt-hours to last 2 hours with the inverter.  

This battery can last up to 5 hours with the inverter. With a lead-acid battery with a 50% discharge, you’ll need a battery that’s twice the size. This is however when running 600 watts continuously. If you were using a 600-watt appliance for 15 minutes you won’t need only around 40 amp-hours. 

Time Power Requirements (Watts)Amps DrawBattery (24v)
1 hr60030150Ah
30 minutes300 1575Ah
15 minutes1507.540Ah

Conclusion 

A 700-watt inverter can power a variety of electronic devices and appliances with a maximum power draw of 700 watts and a continuous draw of 600 watts. To choose a suitable battery for the inverter, you should consider the voltage of the system you are running and how long you need to run the appliance.

Most 700-watt inverters operate on 12-volt DC power, and a 12v 120Ah battery should be enough to run the max continuous output for around 2 hours. Choosing a high-quality battery with a higher capacity than needed can ensure reliable performance and prevent the battery from discharging too deeply.

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