Running two inverters in a small system

[mschulz]

So I read the sticky about inverters and had some responses from some of my other response. If i run a 1000w inverter for a load of 100watts it probably is not runny as efficiently as a 300w inverter would be at 100watt draw. Can you run two smaller inverters off the same battery bank to different circuits?

Example:

500watt inverter connected to lights and power sockets to be used when at the cabin

200watt inverter connected to satellite internet running 24/7

Or is this a totally stupid idea since I will be using a 1000w Pure Sine Wave inverter any way? Don't worry I can take it directly if this is a dumb idea.

[Sunking]

Sure no problem and that is what a lot of people do.

[Sunny Solar]

The only limit as to how many inverters you can connect to any battery/ies is the current you can draw from those batteries.
Using a 1000w inverter for big loads when needed and a 300w inverter for often used small loads reduces the standby draw of the 1000w inverter to zero . Its standy draw may be 2a the 300w inverter mabe 300ma. A worthwile saving over a 24 hr period... If you have all small loads and no big (above 200w) loads its ok to even use 2x300w inverters and spread the loads over them.

[mschulz]

After evaluating my loads, I think this is really the way to go for me. So after looking around for PSW inverters in the 300W-500W range I am only finding those that 120V out put is plug. I want to wire this to the service panel to distribute it around the house. I have seen pictures of people plugging a double male cord from the inverter into a wall plug - I am just not comfortable with that. I would like more of a secure connections.

[Sunny Solar]

Adouble male plug is about as dangerous as you can get.. DONT DO IT.. Hard wiring an inverter may require you to have a qualified electrician do that with an approved inverter. Icant give real advice as don't know where you live or the wiring rules that apply your area,, Be careful .You have fire mabe no insurance if something is not legal/

[mschulz]

Be careful .You have fire maybe no insurance if something is not legal/

Double male plugs - Got it - it just seems like a bad idea. Thanks - this little cabin is so far out there, no insurance anyway. An electrician wouldn't even go out there.

[electrodacus]

So I read the sticky about inverters and had some responses from some of my other response. If i run a 1000w inverter for a load of 100watts it probably is not runny as efficiently as a 300w inverter would be at 100watt draw. Can you run two smaller inverters off the same battery bank to different circuits?

Example:

500watt inverter connected to lights and power sockets to be used when at the cabin

200watt inverter connected to satellite internet running 24/7

Or is this a totally stupid idea since I will be using a 1000w Pure Sine Wave inverter any way? Don't worry I can take it directly if this is a dumb idea.

The efficiency and no load current varies widely with the brand and type of inverters not just with the max power.
In a lot of cases simpler modified sine inverters have better efficiency and lower no load current draw.
But for small enough loads it will be probably more efficient you you use a DC-DC converter and power them directly. This may not be covered by warranty and as I just found out everything is illegal maybe even my advice.
I do not recommend this to anyone just to be clear.
But for my use I converted all my electronics to DC so I do not need to run an inverter. As example both laptops used an AC to DC adapter that provided 19V since my battery bank is about 24V I used DC-DC converters able to provide sufficient current to power the laptops under full load.
They use about 8 to 10W in idle (when reading a web page) and 27W up to 38W under full load
Under this conditions with a 300W inverter (300mA no load) + the efficiency of the inverter at such small loads and the inefficiency of the AC to DC adapter the advantage is clear for a high efficiency > 90% DC-DC converter with 10mA no load current.