Sine Wave Inverter

[Mc4by]

A question for those that know electrics and stuff...
What is a good size for a pure sine wave inverter.
I don't understand electrics (being colourblind didn't help) but I know pure sine wave is better for laptops etc.
When it comes to understanding amps, watts and volts I put my hands up in surrender.
Just looking for something that will handle charging a couple of laptops and camera batteries. I don't need fans, ovens and tv's.
It's not about money it's about getting what works.
I have a 160 watt solar panel that does a great job of keeping the battery charged.

[stevemc181]

A 300watt inverter will more than cover it, particularly if you want to charge a couple of devices at once.
You would be better off using 12 volt chargers for your laptops. Seems pointless to convert DC to AC and then back to DC to charge them. Something like this from Jaycar will easily charge the majority of laptops out there. https://www.jaycar.com.au/150w-car-laptop-power-supply/p/MP3472

You could probably also find a 12v charger for your batteries, I'd be surprised if most camera batteries don't have a USB charging method these days.

[PeeBee]

Go for a pure sine wave inverter to ensure you get compatibility with the electronics. Modified wave or square wave may not work. I have gone thru this myself and it ends up being expensive with 'spare' units sitting around.

[GQtdauto]

All good advice , first inverter I brought was a 600 watt not so cheapie from repco, lasted 6 months , second unit was from a now closed firm in QLD which was 3000 watt around the $800 mark and was an amazing unit , power draw on standby was almost nothing even had a remote , regret selling it with the caravan .
Current unit is also a 3000 watt and is in our camper trailer , far bigger than needed and is an el cheapo so not expecting it to last long .
When it dies it will be replaced by a Less than 1000 watt inverter , have plenty of USB charging ports and 12 volt sockets , most things we have can be charged of these , only two 240 volt items are drill battery and small washing machine for the longer trips .

[mudnut]

x2 Definitely go for a pure sine wave unit. The Blue line is the output of a pure sine wave and the red stepped one is from a modified sine wave unit.

[PeeBee]

I run a 3500w pure sine wave but its sized to run a coffee machine and microwave. It happily runs a grinder and couple of drills at the same time, but mentioned more from the point that i started with a 600W modified square wave from the old Dick Smith, and found more uses for it - have 4 of the things sitting in the garage now of differing sizes! I have used it to power the fridge and TV when we have had power outages - our transformer on the estate we live in regularly trips out. Bit of an extreme example but might cause you to pause and rethink your application and only buy once, maybe?

[Mc4by]

Thanks to all for taking the time to respond and the graph is excellent.
Many really good points contributed and so it comes down to recommended brands.
The range is huge but I assume the quality of some will be dubious.

[GeeYou8]

A 300watt inverter will more than cover it, particularly if you want to charge a couple of devices at once.
You would be better off using 12 volt chargers for your laptops. Seems pointless to convert DC to AC and then back to DC to charge them. Something like this from Jaycar will easily charge the majority of laptops out there. https://www.jaycar.com.au/150w-car-laptop-power-supply/p/MP3472

You could probably also find a 12v charger for your batteries, I'd be surprised if most camera batteries don't have a USB charging method these days.

Can't agree more, pure sine wave are inefficient, DC to DC is a better way to go.
Graham

[Bush Ranger]

I have seen pure sine wave inverters that have the solar panel attachment / plug incorporated. Would these style of inverters be any good?

[Mc4by]

There is rarely an easy answer to even the simple questions :)
The pure sine wave converter could also cover cooking on a TFB by powering a microwave...

[GQtdauto]

Out of curiosity I ran the aircon in the van , it ran for fifteen minutes before cutting out for low battery , on the road when stopping for a cuppa could do toast , microwave and boil the kettle but alas I let the unit go with the van when I sold it .

[PeeBee]

Out of curiosity I ran the aircon in the van , it ran for fifteen minutes before cutting out for low battery , on the road when stopping for a cuppa could do toast , microwave and boil the kettle but alas I let the unit go with the van when I sold it .

Do the numbers. There is a 20 fold amp draw at 12v to 240v, and i am sure the aircon draws a heap, so not surprised your unit went out on low voltage, even with the engine running. You would need a fast idle at least I suspect.

[GQtdauto]

Yeah I know , only two batteries , one not so good , and that power hungry aircon was always going to trip the inverter .
I only did it to see if the inverter could handle the load , which it did in spades .
Did put brand new gel cell batteries in it to sell it .

[mudnut]

On start up, without soft start technology, electric motors can eat up to 8 times their normal running current.