How long will a 200 amp hour AGM battery last?
/How long will a 200 amp hour AGM battery last? with input of a solar panel of 200 watts for 10 hours a day. The battery is used by a fridge with a draw of 4 amps an hour, 3 x led lights using 1 amp and hour, a radio used for 4 hours a day at 1.5amps an hour, also charging 2 x standard iPhone's overnight.
To determine how long a 200Ah AGM battery will last with the given inputs and loads, we need to calculate the total energy input and energy consumption.
Energy input from the solar panel: A 200W solar panel operating for 10 hours a day generates 200W x 10h = 2000Wh (watt-hours) of energy.
Energy consumption by the appliances:
Fridge: 4A x 12V = 48W (since power = current x voltage, and assuming a 12V system)
LED lights: 3 x 1A x 12V = 36W
Radio: 1.5A x 12V = 18W (used for 4 hours a day)
Charging 2 iPhones: Let's assume each iPhone uses a 5W charger (5V, 1A). So, the total power consumption would be 5W + 5W = 10W. Since they're charged overnight, we'll consider this a part of the night-time energy consumption.
Total continuous power consumption (fridge and LED lights): 48W + 36W = 84W
Total energy consumption in 24 hours for continuous loads (fridge and LED lights): 84W x 24h = 2016Wh
Energy consumption for the radio: 18W x 4h = 72Wh
Total energy consumption in 24 hours (excluding iPhones): 2016Wh + 72Wh = 2088Wh
Energy consumption for charging 2 iPhones overnight: 10W x (let's assume 3h charging time) = 30Wh
Total energy consumption in 24 hours (including iPhones): 2088Wh + 30Wh = 2118Wh
The solar input of 2000Wh covers most of the energy consumption, but not all. The difference between consumption and input is 2118Wh - 2000Wh = 118Wh. This energy will have to come from the battery.
To calculate the battery discharge in amp-hours, divide the energy in watt-hours by the system voltage (12V):
Battery discharge = 118Wh / 12V = 9.83Ah
Since an AGM battery should not be discharged below 50% to prolong its lifespan, the usable capacity of the 200Ah AGM battery is 100Ah. Given the calculated battery discharge of 9.83Ah, the battery should be able to support this usage pattern for several days without any issues , as long as there's consistent solar input during the day.
However, it's essential to note that these calculations are based on ideal conditions and do not account for factors such as solar panel efficiency, battery age, or variations in sunlight due to weather or location. It's also important to consider that battery capacity can decrease over time, and the efficiency of charging and discharging can be affected by temperature and other factors.
To ensure optimal performance and battery health, it's a good idea to regularly monitor your battery's state of charge and adjust your usage or system components as needed. You might also consider having a backup charging source, such as a generator, to help maintain your battery's charge during periods of reduced solar input or increased energy consumption.