With the high temperatures in Brazil, the use of air conditioning has become essential for daily comfort. A frequent question arises: is it possible to keep an air conditioner running on just one battery? And for how long? This article offers a detailed analysis of the operating time of an air conditioner connected to a battery.
The first step in determining the autonomy of an air conditioner connected to a battery involves calculating the daily consumption of the equipment. For a 9000 BTU model, considering 1 hour of use per day, monthly consumption is 17,1 kWh. Dividing this value by 30 days, we have a daily consumption of approximately 0,57 kWh, or 570 watts per day.
The next step is consider inverter efficiency, which in this case was conservatively estimated at 85%. This means that to provide the 570 watts needed by the air conditioner, the battery needs to provide approximately 671 watts.
acid battery
The battery chosen for this analysis is the Moura 12 MS 274, with a C20 discharge capacity of 220 Ah. When calculating the stored energy considering a discharge depth of 30% and a battery efficiency of 85%, we arrive at a total of 570,4 Wh available for use.
When relating the energy required to operate the air conditioning for one hour (571 Wh) with the energy stored in the battery (570,4 Wh), it is concluded that the battery can keep the air conditioner running for approximately 46 minutes. This calculation is based on the premise of keeping the battery discharge depth at 30% to preserve its useful life.
Theoretical estimation
In practice, for a complete offgrid system, other factors, such as losses in equipment, peak power of devices and the choice of controllers and solar panels, must be taken into account.
This study provides an overview of the feasibility of using a battery to operate an air conditioner, offering an initial understanding for those interested in alternative energy solutions. The discussion remains open, and we invite readers to share their opinions and experiences in the comments.
