1. What is a inverter?

Inverter is a DC (Direct Current) powered device that can converts power into AC (Alternating Current) power output. The output can be in 230-240VAC, 50 Hz for International power or 110-120 VAC, 60 Hz for North American domestic power.



2. Type of Inverter

Inverter generally can produce Square wave, Modified sine wave & Pure Sine Wave type depending on circuit design. For more detail on inverter , click here to find out


A. Square Wave

The most pioneers in the inverter development but anyhow this type of inverter can’t much produce good output performances if compare to Modified Sine wave and Pure Sine wave


B. Modified Sine Wave / Quasi Sine Wave

Modified Sine wave are the among more common and popular use inverter in the market. It is mainly due to its inexpensive price if compare to Pure Sine Wave inverter. It is more economical type inverter and more than adequate to use for general electrical equipment (not advisable for appliance with speed motors or light dimmers), fans, pumps, drills, saws, microwaves, refrigerators, lightings or computer.

Even though Modified inverter are designed to somewhat simulate Pure sine wave output, but it still unable to produce the same “ pure” output performances. The fact that modified sine wave output could occasionally create electrical noises on your radio or fan or “snow” effects on your video picture


C. Pure Sine Wave

Pure Sine Wave inverter would be excellent to any devices with sensitive calibration. It does not produce any electrical noise interference and it can handle very well for any sensitive loads with perfect and pure wave output. Pure Sine Wave inverters overall capable to generate electrical power that similar to the output of our house wall plug. It is highly recommended to apply to variable speed motors, audio/visual equipment, digital clocks, battery chargers , light dimmers surveillance video or any telecommunications applications.


3. What size inverter do I need?

The size of the inverter always rely on the total power loading that needed. It can be calculated by adding the total watts or amps of all your appliances that you plan to power. You can check the labels from each AC powered appliances which usually easy to locate on how many Amps or Watts off the electricity the appliances uses.

Unless you are equipped with a large size of power inverter, it is not advised to run two heavy appliances at the same time, such as running a refrigerator together power a vacuum cleaner.

Example :

A 100-Watt light bulb consumes just under 1 Amp of electricity per hour. (120 Watts = 1 Amp of AC power)
8 Amps draw of electricity (9 x 100-Watt light bulbs) are approximately the equivalent of 960 Watts or just under 1 kW(1000 Watts of power).


What is Starting Load an Continuous Load ?

a.Starting Load or Peak Surge

Some appliances require an initial surge of power to start up, called a Starting Load .The Starting Load is considerably higher than the Continuous Load and must be considered when sizing the inverter, the battery and the cables that connect the two.

Watts x 2 = Starting Load*

* Some appliances may require a greater starting load (3 to 7 times the continuous rating).

b. Continuous Load

The Continuous load of your application is the amount of power it needs to run over the long term. Once started, an appliance needs less power to continue operation than it needed to start up.
Amps x 120 (AC Voltage) = Watts*

*This is an approximation.


4. How do I charge the battery for my inverter?

Because inverters operate from a DC (Direct Current) power source, usually a battery bank (one or more batteries), the battery source will have to be recharged at some point. (Remember that a battery discharged more than 50% is probably close to being dead.)

Most cars and trucks recharge their batteries from an onboard alternator. Depending on the inverter load and runtime required, most power use applications will be covered by the charged battery, augmented by the operating alternator supplying a continuous charge to the battery.

If the load is large (air conditioner, large draw power tools, large microwave, food freezer, ice cream machine, etc.), verify that the installed vehicle alternator is of large enough capacity to operate the vehicle’s power requirement as well as to fulfill the capacity of the inverter load.

If not, a motor throttle installation may be required to carry a small load, a larger alternator may be required, or a larger alternator, battery isolator and additional onboard battery bank may be required in order to meet the power requirement of your large load. Remember: it takes 10 DC Amps to run 1 AC Amp of power.


5. How long can I run the inverter on my battery?

To calculate the power drain on your battery bank, it is vital to estimate the reserve power (Amp/Hour) of the battery, plus the total of Amps that the inverter will need.

Note: 10 DC amps (120w DC) to power 1 AC Amp of power use)

Step 1 : Multiply the Reserve Minutes by 0.3 in order to get the battery Amp/Hour reserve power

Each battery has a “Reserve Minutes” rating marked on its label, next to the “Cold Cranking Amps” rating. You can multiply the Reserve Minutes by 0.3 in order to get the battery Amp/Hour reserve power:

Reserve Minutes x 0.3 = Amp/Hours (Eg: 150 x 0.3 = 45 A/H)
Step 2 : Divide the Continuous Load Wattage requirement by 10.

To estimate the maximum battery power the inverter will require to run an appliance, divide its continuous load wattage requirement by 10.
Continuous Load (Watts) / 10 = Maximum Battery Power (Eg: 450 / 10 = 45)
(Eg: 45 A/H / 45 Amp Draw = 1 Hour)

*Large electrical loads will require large battery banks to power them. Batteries will only discharge to 50% of their rating.
Sizing a battery bank required expert configuration skills.