1. Battery Basics: Lead Acid vs Lithium Phosphate

Before we delve into specific applications, let’s discuss the two major types of batteries in the 200Ah range:

• Lead Acid Batteries: These are commonly used in deep-cycle applications. A 200Ah lead-acid deep-cycle battery running a 400-watt DC load with a 50% recommended Depth of Discharge (DoD) will last for approximately 3 hours. For instance, it can power a 400W-rated refrigerator for about 25 hours at a rate of 40 watts per hour.
• Lithium Phosphate (LiFePO4) Batteries: Although more expensive, LiFePO4 batteries offer several advantages. They are intrinsically deep-cycle, allowing them to be discharged to a much greater depth than lead-acid batteries. Most LiFePO4 batteries can be discharged up to 95%, but it’s recommended to stay around 80% to maximize battery life. A 200Ah LiFePO4 battery connected to a 400-watt DC load with an 80% DoD will last for almost 5 hours. It can power a 400W-rated fridge for about 55 hours.

2. AC vs. DC Loads

When considering battery runtime, it’s essential to distinguish between AC and DC loads:

• AC Loads: These are appliances that require alternating current (like what you get from utility companies). To power AC loads, an inverter is needed to convert DC to AC. High-quality inverters are about 95% efficient, meaning you lose 5% of running time due to inverter electronics. A 200Ah lead-acid deep-cycle battery, with a 50% DoD, will run a 400W AC appliance for about 3 hours.
• DC Loads: These are devices directly powered by the battery (such as solar panels). Since no inverter is involved, DC loads generally run longer. For example, a 200Ah battery can power a DC load for more extended periods.

3. What Can a 200Ah Battery Run?

Unless you’re using the battery for marine or RV purposes, 200Ah batteries are often associated with home appliances. Here’s an approximate rundown based on a 200Ah lead-acid deep-cycle battery with a 50% discharge (compensated for inverter losses):

• LED Lights: Several days
• Laptop or Phone Chargers: Several days
• Small Fans: A day or more
• TVs: Several hours
• Refrigerators: Around 3 hours
• Microwaves: About 1 hour

Remember that these estimates are fairly linear, except for appliances with large motors (like fridge compressors) that cycle on and off.

In summary, a 200Ah battery is a versatile power source, capable of running various home appliances. Whether you’re camping, boating, or preparing for emergencies, understanding its capabilities ensures you make the most of your battery investment.