Theta 500W Modified Sine Wave Inverter
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Theta 2.0 inverters are principally meant to be used with solar, wind or hydro power systems for a home or business totally disconnected from the electric utility company.  They can also be used for providing emergency backup power to homes that currently use the power from an electric company.  Inverters with the built-in AC charger option are particularly well suited to providing seamless backup power.

Theta 2.0 Inveters are designed in compact, lightweight and portable!  Inverters plug into a vehicle's lighter socket, and are an easy solution for your small power needs.  These unique and convenient inverters can be used for small recharging power needs such as video cameras, laptop computers, and cellular phones.    AC outlet is built into the face of the Inverter, and this inverter can be used to run your TV, VCR, lights, computer and satellite receiver.

Connect direcly to 12V battery and turn to mini power station for powering small appliances (220-240V).  It also equiped with USB power outlet for 5Vdc power and ideal for charging smart phone. 

Ideal for: 

  • RVs and Campers
  • Long Haul Trucks
  • Boats
  • Mobile Office
  • Service Vehicles
  • Emergency Back-up Power


General opinion over the last few years was that the modified sine wave inverter was dead, and the pure sine wave inverters would rule the world sales of modified sinewave inverters have continued to out-grow sales of sine-wave, proving that there is plenty of life left in this technology.  The principle reason is that most of the equipment such as mobile phones, TV, drill chargers and all that type of equipment which used to have a problem working with modified sine wave tends now work fine on modified sine wave as the effected equipment now tends to use switch mode power supplies in there design which works fine with modified sine wave.  This meant that rather than the problems getting worse over the years the problems have diminished, however this is not to say that the odd microwave, drill vacuum cleaner would not work (if there is a thyristor control circuit employed then this can still be a issue ) but there is no question this is becoming more rare as the years go past, plus its still usually a lot cheaper to replace a old microwave to a different model which will work rather than spend heavily on a pure sine wave model to make it work.

Solar Power Mart has invested in a new range of modified sine inverters because they are smaller, lower cost, offer better performance, are more efficient and more reliable than sine-wave.  We at Solar Power Mart have always found the modified sinewave inverter more than adequate for general requirements in remote homes, boats and vehicles.  There is still the odd appliance, such as washing machines, where modified sinewave inverters simply do not work, but all in all they do a great job – especially considering their cost.

CE Aprroval        ROSH

The Theta 2.0 Modified Sine Wave Inverters are CE and ROSH certified products and come with one year limited OEM warranty. 


Download: Theta Inverter User Manual & Technical Specification (Please click to download)


Inverters are used in any electric system where AC power output is needed.  You are already familiar with AC power:  it is the power in your house when you plug something into the wall.  The inverter's job in a solar energy system is to convert the DC electricity, such as from a battery bank, to AC electricity that can be used with typical household appliances.  Solar panels also produce DC electricity.  Inverters are used in homes, business, RVs and boats.  Off Grid Inverters are common in solar electric.  Solar electric (or PV) systems can operate with or without batteries. Since each inverter needs proper disconnects on the AC and DC side, often people choose one of our self contained Solar Battery.  By mounting one or two inverters on a Solar Battery, that is wired with the appropriate disconnects, you have yourself a neat and safe inverter system.

Sizing an off grid inverter (that needs batteries) is relatively straight forward.  It must be large enough to handle the total amount of watts you will be using at one time.  Start by listing all of the appliances, etc that you use and their wattages in our load calculator.  This form will display the number of watt hours you use in a day.  In order to properly size an inverter, consider which of those loads you will be using simultaneously and add up their wattages only.  For example, if you will be using the 1500 watt microwave at the same time you will be running 100 watts of lighting and also running a refrigerator that will draw 500 watts of instantaneous power, you will need an inverter that can handle at least 2100 watts (1500 + 100 + 500).  Once you have identified a minimum wattage, you will select an inverter that has the same nominal voltage as your battery bank (12, 24, or 48 VDC).


  • Item #: SPM500MS

Theta 500W Modified Sine Wave Inverter

Price: RM244.40
Availability: Out-of-Stock
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