idle consumption - does it matter if loads are running all night?

I was considering either the MPP or Growatt all-in-one inverter over the 48v Midnite Classic Lite I have (but haven't installed yet) and read that the MPP and Growatt have a high idle consumption whereas some nicer ones, like Xantrax have a low idle consumption but can cost 3x to 5x more. I'm wondering if the idle consumption is in addition to any appliances you have running or would it be a moot point if I have something running 24/7 like a hydroponics pump or a cc miner?

Yes, it is extra power used on your batteries. So if you need to power a 200 watt light, you can figure that your batteries will output 275 watts. If you need to power a 500 watt light, figure your batteries will output 575 watts. In reality they'll probably power even more than that since the inverter is not 100% efficient. So a 500 watt light probably needs like 530 watts, then add in your 75 watts and you have 605 watts to power a 500 watt light. It'll work out something like that. Just buy an extra battery. That's much cheaper than buying those expensive inverters.

Agree with @priorityelec but to me it's an expectation thing and a scale thing.
Expectations - In my trailer, I knew that 60w/hour idle (MPP Solar 3048LV) is background drain for the privilege of instant power 24/7 - so I planned for a little large battery to avoid disappointment in expectations of run time.
Scale - In my home, I have up to 200w/hour idle consumption (AIMS 12,000w) but is mitigated as the load goes up. However I run 2500w/hour as a baseline and overall have 16% losses. Its annoying but a tradeoff to have 12,000w (240v@50a) capable inverter at a lower price.

Solar (and batteries) are a bit messy as the sun / clouds change constantly and batteries work but have discharge curves with sweet spots and knees and inverters have losses ... so overall I try be be more zen than OCD about some of these things

SunbeltLocked said:

I was considering either the MPP or Growatt all-in-one inverter over the 48v Midnite Classic Lite I have (but haven't installed yet) and read that the MPP and Growatt have a high idle consumption whereas some nicer ones, like Xantrax have a low idle consumption but can cost 3x to 5x more. I'm wondering if the idle consumption is in addition to any appliances you have running or would it be a moot point if I have something running 24/7 like a hydroponics pump or a cc miner?

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I don't have an all in one inverter but I do have a 4000 watt inverter that uses 6 watts at idle. I also have a 6000 watt inverter that uses 50 watts at idle. The 4000 will consume 204 watts in a 24 hour period just to be on and the 6000 will use 1200 watts just to be on for 24 hour period. These power draws need to be added to whatever other systems pulling in that same period. Both will work but more battery storage is needed for the 6000 watt due to its larger idle draw.

Ah, just the nature of the beast.

SunbeltLocked said:

I was considering either the MPP or Growatt all-in-one inverter over the 48v Midnite Classic Lite I have (but haven't installed yet) and read that the MPP and Growatt have a high idle consumption whereas some nicer ones, like Xantrax have a low idle consumption but can cost 3x to 5x more.

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Keep in mind here that you are making an apples to oranges comparision here. The MPP and Growatt are AiOs whereas the Midnite is a charge controller.

That being said, the combination of my Midnite200 and the XW+6848 has a background consumption of about 700W per day. Or about 30W/hr.

I have a 70" tv, that is on for at least 16 hrs a day.
Idle consumption wasn't even on my radar. lol

I will offer that the handful of AC refrigerators that I've been around to see power 24/7. The search mode messes with thier electronics causing it to run to the defrost cycle more than it needs to be which really increases energy usage.

SunbeltLocked said:

Ah, just the nature of the beast.

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Yep, in all but the tiniest of systems the tare loss of the inverter running 24/7 just gets chalked up to the cost of being off grid.

OffGridInTheCity said:

so overall I try be be more zen than OCD about some of these things

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true

SunbeltLocked said:

I was considering either the MPP or Growatt all-in-one inverter over the 48v Midnite Classic Lite I have (but haven't installed yet) and read that the MPP and Growatt have a high idle consumption whereas some nicer ones, like Xantrax have a low idle consumption but can cost 3x to 5x more. I'm wondering if the idle consumption is in addition to any appliances you have running or would it be a moot point if I have something running 24/7 like a hydroponics pump or a cc miner?

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It certainly depends on your situation. In my off-grid configuration, my nighttime usage drifts down to around 130W if I leave the Internet on and probably closer to 35W if I turn it off. I WAS happy with my Sol-Ark 8K with a typical self-load at 60W most of the time (varied from ~60-90W), but after a recent firmware update the self-load shot up to 90W (varies from ~90-120W); not insignificant when you are trying to stretch battery over a few cloudy days.

Moral of the story seems to be that even with the "nicer ones", you might get screwed...

Hmmm to toss a Rock in the Pond.
I run with Midnite Solar Controller but Samlex EVO-4024 Low Frequency Pure Sine Inverter/Charger - 18W idle consumption "not in ECO mode".

FullTime operations can absorb the Idle Consumption as operational overhead and really it is not that much in the grand scheme of things.
AIO's have many advantages in "general" but it is COMPROMISES so you work with that. They are fine in Full Time Installations as that's just overhead but they are not great for Part-Time residences like weekend cabins, when everything is shutoff.

Do note: The higher up in Tier Quality you go the more efficient the equipment gets AND there is always a difference between Low-Frequency & High-Frequency systems and their stand-by usage. DO NOT FALL FOR THE TWADDLE that Low Frequency Systems use more power, old wives tales echoed by the unknowing with circumstantial assumptions & conclusions.

NEVER MENTIONED IN HERE but look at GoodWe AIO's and other Top End brands. There are many more brands out there & more goodies coming from existing makers.

priorityelec said:

If you need to power a 500 watt light, figure your batteries will output 575 watts

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Your talking about inverter efficiency, OP asked about idle consumption. There are entirely different things.

I define idle consumption is the amount of power required to keep the electronics of the inverter/SCC powered on but not actually outputting any power. Under that definition it is irrelevant as you have the inverter outputting power 24/7 and never "idle" (at which point having a discussion concerning inverter efficiency is a thing. )

WHile Steve_S mentiones idle/standby consumption of low frequency vs high, I will clarify that the inverter efficeniceny is no were close between the 2. The LF with its huge transformer will always ave higher conversion loss than a electronics only HF unit.

schmism said:

The LF with its huge transformer will always ave higher conversion loss than a electronics only HF unit.

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Depending on the quality of the components used within. Easy t make an 85% Efficient one with cheap bits, 95% efficient one with $$$ bits.
There are both HF & LF that are well into the 90% efficiencies with low standby / idle current use. They just cost more $$$.

Also a mention on point...
Low Frequency will handle 3X surge whereas HF 2X surge.

If the inverter is not at idle there is no idle draw. Check the efficiency curves is a better indicator.

schmism said:

Your talking about inverter efficiency, OP asked about idle consumption. There are entirely different things.

I define idle consumption is the amount of power required to keep the electronics of the inverter/SCC powered on but not actually outputting any power. Under that definition it is irrelevant as you have the inverter outputting power 24/7 and never "idle" (at which point having a discussion concerning inverter efficiency is a thing. )

WHile Steve_S mentiones idle/standby consumption of low frequency vs high, I will clarify that the inverter efficeniceny is no were close between the 2. The LF with its huge transformer will always ave higher conversion loss than a electronics only HF unit.

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This is true, but you still have this same draw on your batteries whether the system is idle or not. If you power 500 watts, it's not like the idle consumption 75 watts goes to 0 and your batteries pump out 500 watts. I figure he's looking at how much power he'll burn overnight. Either way, he should have enough info.