Inverter efficiency - 12v vs. 24v

[CoastalCajundude]

After searching for posts and nothing being specific to my brain bender - the choice of a 12v or 24v 4000w inverter. This will be for providing AC power only, (have a separate 12v dc parallel for lighting, phone chargers and fans), so I'm looking for feedback or data on which is more efficient. Data sheets on the inverters all show =>90% for runtime conversion, but I cannot find data on which is better for long AC current draw. My brain says 24v, but.... Anyone have a link to back me up, or have systems built that are producing good numbers?

 

[Tecnodave]

12 volt inverters have the least effeciency of any inverter which is usually <88% whereas quality 24 volt inverters are 95% or so and quality 48 volt inverters are 96-97% effeciency.

Rule of thumb......1000 watt inverter 12 volt is ok choice
2000 watt inverter 24 volt is very definitely the better choice
4000 watts 48 volt inverter is the best choice

The higher the battery voltage the less loss in wiring and less loss in the inverter itself

Most modern whole house systems are 48 volts.

It is also dependent on what you are doing with the power, If you are a camper with minimum requirements 12 volt will work, If you are a couple 24 volts is more appropriate, but if you have a household of adults and kids then 48 volts will be far superior in the long run.

 

[CoastalCajundude]

Thanks, for the feedback. Pretty much along the lines of what I was thinking, but one stroke shakes your confidence. Luckily we're only powering a few appliances on this bank.

 

[Steve_S]

12V caps out generally 2500-3000W
24V caps out generally 4000-5000W
Above 5000W go with 48V
Regardless is Single Phase 120V or Split Phase 240V output.
- Low Frequency Inverters are capable of 3X Surge Handling and are better for motors (fridge, AC, Compressor etc) as well as inductive loads.
- High Frequency Inverters cost less, they are capable of 2X Surge Handling and NOT good with high surge starts especially motors. You have to seriously over capacity the Inverter to have high surges.
REF: https://www.magnum-dimensions.com/k...rsion-methods-explained-high-frequency-vs-low

Two things to consider:
1) Inversion Efficiency: Value Grade gear is A-Typically 88% or less, Tier-2 is usually 88-92% efficient and Tier-1 products are 92% up to 97% efficient. Of course there is a dollar value as the higher grade costs more due to the better quality components used.

2) Stand-By Power Efficiency: Many AIO's and High Frequency Inverter/Chargers will use more power in Standby Mode or even Eco-Mode, Lower cost Low Frequency systems can also be inneficient in standby. Higher Quality Inverter Chargers (and several High End AIO's) can use as little as 6-8W Standby while the less costly can end up using up to 200W in Standby, some people are even reporting 300W in standby.

I am 100% offgrid, run my home with a 24V Samlex EVO-4024 and over 1000AH of LFP. Well Pump is a deep well Grundfos SQ5 120V/Softstart which is 280' deep in my well, that pushes to a 50 Gallon Pressure tank and then another 75' to house from the pumphouse/powerhouse. I can run my MIG Welder & 3HP compressor without issues.... I gave away my AC as there is no point as the house design works as intended and it never gets above 26C/79F in my home even when it's 40C/104F outside.

Hope it helps, Good Luck.