A 200Ah Lithium Iron Phosphate battery is an ideal choice for off-grid applications. With a longer lifetime than lead-acid batteries of similar sizes, these cells outperform in extreme weather conditions and are more resilient to physical damage and wear. But what will be its performance against a high-power demanding electric oven? 

Our 200Ah battery can support the electric oven for a max 18 minutes. Combining two 200Ah batteries can allow you to run the electric oven for longer.  

In this article, we take you through the numbers and tell you as to why you can only run an electric oven for 18 minutes and what you can do to increase capacity. 

Power Consumption for an Electric Oven

Electric ovens come in many different sizes and wattages. For example, a small oven can have a wattage of around 1,000 watts, while large ovens can have wattages as high as 5,000 watts. 

The standard for most household microwaves is about 1000 watts, but some models have as much as 2000 watts of power. The cooking method will also affect the amount of power needed. For example, baking requires more power than broiling or roasting because it requires more heat.

Electric Oven Watt-Hour Energy requirement 

Electrical energy is measured in watt-hours. The number of hours you will run your electric oven dictates how much energy it consumes.

To calculate Watt-Hours you multiply the Wattage of the device or appliance and multiply by the number of hours you use the device. 

Watt-Hours = Watts X Hours 

If you want to use an electric oven for 1 hour, you will need 2000 Watt-hours of energy or 2 Kilowatt-hours. 

This is the energy required to run the battery but to see whether the battery can match up to the electric oven we need to calculate the amps draw. 

How Many Amps does an Electric Oven draw?

In order to get the amps draw of the electric oven you will need to convert the Watts to Amps. To calculate the amps draw of an appliance you divide the Wattage rating by the voltage of your system. 

A 2000-watt electric oven will need around 16.67 amps to run when using it from the standard 120V outlet. This is the number of amps that it will be drawing from the inverter. Depending on the DC voltage of the inverter you can calculate the number of amps the electric oven will be drawing through the inverter.

The voltage in a battery bank is usually between 12v and 24v depending on how you wire the system. 

2000Wh/12v = 166.67 Amps

2000Wh/24v = 83.33 Amps

So can our 200Ah battery support this? 

How Many Amps Does a 200Ah Battery Produce

Amp-hour rating in batteries gives the charge in amps that can be drawn from a battery over a certain time given in hours.

A Deep Cycle Battery battery is intended to produce the charge for a long period of time like 20 hours. So for a 200 Ah battery, it should produce at least 10 amps over a 20-hour period. 

However, you can go higher or lower depending on the appliance you are using.  Deep cycle batteries are recommended to be discharged at 20% of their capacity so for a 200 Ah battery the max discharge per hour would be 40 amps meaning it can last 5 hours.

How many watt-hours is a 200 Ah Battery 

You can use the following formula to determine how many watts can be drawn from a battery.

Watts = Volts x Amps

So if your battery is 12v and has a 200 Ah capacity, then you can draw 2400 Watts from it. This is for the full battery cycle. With the 40 amps max draw it means you can get 480 watts max per hour. You can push this to 50 amps or 600 watts per hour with LiFePO4 batteries. 

How Long Can a 200Ah Battery Run an Electric Oven

We’ve already seen that an electric oven will need as much as 166 amps in order to run in one hour. Our 200Ah battery can only support up to around 40 amps or 480 watts per hour.  This power however can support the electric oven for a fraction of the time. 

To calculate the time you” ll need to take the watts the battery can support and divide it by the wattage of the appliance. 

So 

600/2000 = 0.3 hrs 

Our 200Ah battery can support the electric oven for a max of 18 minutes. This is still useful and you can use the power from the battery to cook some chicken tenders with plenty of capacity to spare. 

Also, consider running an electric pressure cooker off the battery as it has less power requirements.

Conclusion

With an amp draw of around 166 amps, this is almost equal to the total amp-hours of the battery. I would recommend you use a 24v system as the amp draw will be less compared to the 12v system. With over 80 amps draw you will need quite a big battery. 

Batteries are recommended to be discharged at 20% of their capacity each hour.  So you will need a 450Ah battery using a lead acid deep cycle battery. However, a Lithium Iron Phosphate battery has a bigger C rating and is much more forgiving when pulling huge amps. 

With a LiFePO4 battery, you can pull as much as 50% of its capacity. This is not recommended over a long period of time. We are not going to overstretch it but is possible to use a 400Ah 24V LiFePO4 battery or two 200Ah 12V batteries wired in series.