How many watts is suitable for a vehicle inverter?

How many watts of on-board inverters are suitable for use depends on the situation. The power of vehicle inverters generally ranges from 20W to three or four kilowatts. Commonly small ones are output through cigarette lighters, and high-power ones are connected to batteries through connecting wires. When selecting, the power should be calculated according to the actual needs through the formula required power = maximum power of the equipment x coefficient (resistive load coefficient 1.5, inductive load coefficient 2), and the purpose and redundancy should also be considered. It is recommended that the car inverter connected to the cigarette lighter should not exceed 120W (see the car manual for details), and the car battery is generally from 500W to 2000W (see the car for details)Instructions).

If you only use some small electronic devices, such as mobile phone chargers, tablet computer chargers, etc., their power is relatively small, and tens of watts of vehicle inverters can meet the demand. These small devices are resistive loads, and the required power calculated according to the above formula is not large. The vehicle-mounted inverters of 20W and 40W specifications output by cigarette lighters are enough to cope with them.

If you plan to use electrical appliances with slightly higher power, such as laptops, the power generally ranges from tens of watts to more than one hundred watts. At this time, it is best to choose a vehicle inverter with a power of around 100W-150W. However, it should be noted that if it is connected through a cigarette lighter, in order to avoid burning out the fuse, it is best not to exceed 150 watts (because the maximum fuse connected to the cigarette lighter is 20A). If there are clear provisions in the car manual, the inverter that does not exceed the specified wattage should be selected in strict accordance with the requirements in the manual.

When it is necessary to drive electrical appliances with higher power, such as small refrigerators, electric kettles and other inductive load appliances, it is necessary to consider using high-power vehicle inverters, and connect the batteries through connecting wires. In this case, the required power must be calculated according to the formula (inductive load factor 2), generally

It is said that the power of the vehicle inverter connected to the car battery can range from 500W to 2000W. For example, for an inductive load electrical appliance with a power of 300W, the required inverter power calculated according to the formula is 300x2 = 600W, so you need to choose a vehicle-mounted inverter with a power greater than 600W and a connected battery.

In addition, when directly connecting the car battery, although there is no strict limit on the power of the inverter in theory, you must pay attention to the battery voltage. The minimum engine starting voltage is about 10.8 V. Moreover, when the power of the inverter connected to the external car battery is large, since the power of the generator generally does not exceed 1000 watts, the charging may not keep up with the discharge speed. In this case, an auxiliary battery may need to be added.

In short, when choosing a vehicle-mounted inverter with appropriate wattage, we must comprehensively consider the power type of the electrical appliances used (resistive load or inductive load), the connection method (cigarette lighter or battery), and the limitations of the car itself (such as the specifications in the instruction manual, battery voltage, etc.) and these factors. Only through comprehensive weighing can we select a vehicle-mounted inverter that can not only meet the electricity demand, but also ensure safe and stable use.