Inverter Buying guide

Choosing the right inverter for your needs – perhaps it is for use in your rv, car, boat or just home, can be overwhelming so much information out there from several manufacturers and resellers!

I have listed below my top 6 tips to help you choose the best inverter type, capacity and features for your needs.

1. Choosing the right inverter capacity (watts)

You need to size your inverter well enough to avoid overload by the connected appliances. To do this, you need to pay attention to both the inverter’s continuous and surge power rating.

Continuous power rating
A good way to get the continuous power rating right, is to list down all the likely appliances and their sizes (watts) you expect to connect to the inverter. 

Now that you know the expected appliance load, provide for additional capacity. Your aim should be that the total appliance load does not exceed 80% of the inverter’s continuous power rating.

For example, if you inverter size is 1,000 W your maximum appliance load size should be 800 W.

This safeguard helps in case of overrated inverters, i.e. the manufacturers’ quoting higher power rating that can only be sustained for a short period.

Surge power rating
The surge power or initial power that certain types of appliances draw for a fraction of a second when starting up is also important.

Check whether any of the appliances you plan to connect to the inverter have motors or coils in them like fridges, vacuums, compressors, older CR monitors (hardly used these days)

If so,  note the surge rating power of these appliances. Make sure that the combined surge rating of these appliances (if starting at the same time) does not exceed the inverter’s surge rating otherwise your inverter will be damaged!

Lighting, heating appliances and small electronic appliances do not have surge power requirements.

2. Choosing a modified sine-wave vs. pure sine-wave inverter

When you need to power appliances with motors such as fridges, microwaves or sensitive equipment
such as oxygen concentrators or laptops then choose a pure sine wave inverter.

They need “cleaner” power such as produced by the pure sine wave inverters to run properly. Otherwise for non-sensitive appliances, a good quality modified sine-wave inverter will work.

3. To buy a hybrid or non-hybrid inverter

Sometimes, you have a setup that needs to switch among several power sources – shore power, generator and solar/battery power?

Will your appliances be supplied by more than one per source or not? In such cases, use a hybrid inverter. If on the other hand, it is a single power source like a battery, then a non-hybrid inverter is enough.

4. To use a remote control switch or not

How convenient will it be to switch on/off the inverter from its installation location?

Large inverters >2,000 W need to be connected close to the battery bank, say in a power room to minimise energy losses from long cable runs. 

If the inverter is installed away from the appliances it is supplying power to, then consider buying a remote switch to conveniently switch the inverter on/off.

5. Well-known vs. unproven brands | commercial vs. consumer grade inverters

My take on this one is to consider how critical the inverter supply is to your needs.

  • Do you for example plan to use the inverter power for servers that need to be constantly running?
  • Is it providing power to equipment critical to the success of your business
  • Are there alternative power sources besides the inverter?

If it is a critical application to life, success of business or any other aspect of your living , better that you stick to well known brands and commercial grade inverters by well regarded manufacturers.

6. Check other user’s feed-back

Don’t buy based on manufacturer specifications alone – read about other user experiences on reliability, support, honoring of warranty terms to minimize risk of falling victim to bad experiences that other users have faced with that particular model.

I hope that the tips above help you make a better choice when confronted with the several and often confusing features.

Related topics

How long battery lasts with different appliances
Appliances that can be powered by a 300 watt inverter
Appliances that can be powered by a 1,000 watt inverter
Appliances that can be powered by a 1,500 watt inverter