I have an apex300, 1xB300k and 2xB300. Charged using grid and providing 85w or so of power for networking equipment. SOC is kept at 80% using self consumption mode. When I look at energy use, I noticed the Apex300 consumes 4.6kwh from the grid each day to supply 2.1kwh of energy. The grid consumption is accurate based on my emporia monitor. Where did the extra energy go? Is it this inefficient? Are my settings wrong or is there something wrong with my unit?
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The Apex 300 is a high-power unit and you’re only taking 85 watt from the inverter. Just running the inverter and the unit itself consumes quite some power and that’s the efficiency loss you’re experiencing. Your unit is working as designed. If you use for example, 1500 watts you will see that your unit will become a ton more efficient.
If your networking equipment can take the DC output from the Apex 300 then you can turn off the inverter and then the unit will be more efficient at lower wattages.
My AC300 setup has the same inefficiency at lower wattages. It’s the drawback of big inverters. Perhaps they should make a dual inverter unit once. A small and efficient one for low wattage use and a big one for the heavy work.
I understand a 3.8kw inverter would take some power, but this seems like a lot. The extra 2.5kwh /day would imply over 100w of wastage. That is about 3% of inverter max power, which isn’t good. Apex300 was advertised to have low idle draw, this isn’t low at all.
Why would the inverter be on in the first place? This is plugged into grid 24/7, won’t it just do a pass through? My device is on 240v mode and the devices are plugged into the left side sockets on the front.
Hi, I’m in the UK
Midnight on the 16-09-25
2 Apex 300 + 2 x B300K fully charged, and connected to
HUB A1
Direct grid connection (12:00 am - 5:30 am)
Each APEX 300 + 1 connected battery in stand-by mode used 100W each hour
I think I made a mistake buying 3 x APEX 300 + HUB A1 + SolarX 4K
Selling them on eBay looks like the only way to cut my losses.
Why would the inverter be on in the first place? This is plugged into grid 24/7, won’t it just do a pass through? My device is on 240v mode and the devices are plugged into the left side sockets on the front.
That’s a good one and that’s the pain point. Perhaps with a design change the inverter can be off by default when in UPS mode and only switch on when there is a power outage. That would give a whole lot of efficiency and perhaps that is how traditional standby / line interactive UPS systems for PC’s and servers work.
The plugs on the left says 0ms UPS while the ones on the right says 20ms. I assume that 0ms means it is an inline UPS where the inverter is powering the output. Is the 20ms pass through? I want to be able to charge this using solar and grid, up to 80% SOC, but don’t want to run waste 100w doing nothing. Can I have this function as pass through only when the grid is available?
Can someone explain how does the different UPS modes work? Especially the time based modes and the various sub modes there.
Looking back through my energy use history on the app (thank you Bluetti for providing that), I can see that my grid usage jumped quite a bit when I switched from 120V inverter mode to 240V inverter mode. Back when I was on 120V AC mode, the Grid pulled 2.4kWh a day and supplied 1.7kWh of AC. When I switched to 240AC output, the grid input jumped to 4.2kWh and AC output increased to 2.1kWh without any changes in the load. Perhaps this is much more efficient in 120V mode where it can do grid pass-through, but in 240V mode than both phase inverters need to be on since my input is only 120V, something has to make the 240V from the battery. Will do more testing and advise.
Check out Jasonoid’s Best Deal of 2025?! on YT. He does an excellent job of explaining how the 2 seperate inverters work in tandem with the voltage selector switch and the 2 different UPS modes. Some others reviewers mention it, but he has a clear way of explaining it. Just as an important FYI the 0ms ups (left side outlets) only works when the voltage selector is set 240V.
Further observation suggest that in 240V AC output mode with 120V grid input, the Apex300 doesn’t pass-through the grid power to the AC load (at least not the plugs on the left, didn’t try to ones on the right). So the inverter is running to power the load. The power profile is no AC input followed by spikes as the battery recharges. This results in a lot of overhead where total grid input far exceeds In 120V AC mode, the left plugs are directly powered by the grid, with grid input being same as AC output. A couple times a day, grid input would spike to charge the battery but overall non output based consumption averages to maybe 25W. In 240V AC mode, powering a 85w AC load, the non output based consumption around 100w.
I would avoid using 240V output mode unless it is really needed, and would avoid powering small loads with it.
I am not sure what to think yet. I know that Hobotech did the parasitic inverter load tests and he didn’t see any difference between 120V and 240V mode. This kind of makes sense to me, either way both inverters are always powered on and are working in phase or 180 deg out of phase. I am thinking the jury is still out? Not disregarding what you are saying one bit, just not sure if something else is going on also? I am not sure if the app is fully accurate as I am still trying to wrap my mind around a few things it reports.
snowstorm you grid draw does seem excessively high. I am running a full size fridge/freezer in a garage. The normal draw is about 85 watts unless in a defrost mode where it jumps to about 165 watts. Depending on the ambient temperature it might run as much as 18 hours in a day since it is in a hot environment. Anyway your grid draw is way more than mine and I am operating in 240V mode. I believe the app is showing me correctly. Yesterday I made 2.8kWh from solar, and my fridge drew 1.9kWh and I drew .6kWh from the grid. So if we take the 2.8kWh and add in the Grid .6kWh we get a total of 3.4 and the fridge used 1.9 so I lost 1.5kWh running the inverters and the electronics. this is a bit higher than what the tubers have calculated as daily parasitic load. And as others in this string have said the calculated efficency is not great for low powered loads and it will only go up on paper if you increase the load as the ‘daily power tax’ for the unit remains the same no matter if it is producing zero or higher loads. your basically losing 2.5kWh a day which seems high.
I went thru a weeks worth of data, and my unit is consistently wasting 1.5kWh every day. The solar produced and the AC load vary every day as one would expect, but it is always adding up to 1.5k wasted. I am going switch my unit to 120 volt mode, I will let u know if a see an improvement in a few days. I went back and watched Hobotech he tested it at only .6kWh for a 24 hour parasitic load test and reported that the unit would last at 4.75 days inverter on with no loads. Jasonoid and Johnny’s Weekend reported very similar numbers. I think someone from Bluetti needs to explain this better to us or pushout a firmware rev. Something for sure is not matching our useage to what the YT reviewers reported for usage.
You can see exactly where I went from 120v output to 240v. The overhead loss totally jumped. It is interesting that the measured AC out also increases a bit even though the load was exactly the same.
In early August I was running time of use so pass through was inactive e between 4-11pm. In mid August I switched to 240v and it never pass through, all AC out is driven from the inverter.
From what I can see, the Apex300 has made a bunch of improvement to the inverter and the inverter consumes a lot less power when it is idle. So when nothing is plugged in, it doesn’t consume that much power in 120v or 240v mode. There is probably a good “hot standby” mode where it draw low power, where previous AC300 would draw a lot more. However, it isn’t that efficient at low load, which can be seen if you apply say 100w constantly on it. It seems to be worse at 240v compared to 120v, perhaps there is more overhead to generate the split phase and run 2 inverters instead of one.
Observations so far
- Inverter idle with no load ~ 25w
- AC load using grid pass-through (inverter idle) ~25w
- Inverter running a low power AC 240v mode ~75w
Grid to AC output passthrough appears to be active under the following situation, and when that happens, the inverter idles and losses is minimal, maybe 25w:
- Using 120V input
- AC power output is < than what you can draw in on the grid
- in UPS mode, or in another mode where it can draw from the grid based on the current time and SOC
I see the jump. What happened August 24th?
You are using the 0ms UPS mode, in that mode it is a double conversion (also called online or true online) UPS and has the highest loss. You cannot have both a 0ms cutover and no loss passthrough, though you can get very close in datacenter scale BIG UPS’s that use other tricks. To go from passthrough to active power something has to switch states and there is a cutover time. In a double conversion UPS the inverter is always on and powering the load from DC. That DC comes from a battery charger connected to grid input. In the case of the Apex that charger is the other inverter that runs the right side outlets. I spend some time talking about this with diagrams in the Apex video I made:
Skip to 18:00 to see that part
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Thanks for the info!
Yes, I was using the 0ms UPS in 240V mode, which adds to the overhead. I can tell that the inverter is powering the AC out since grid input is 0% most of the time, but every 1-2 hours the grid input would come on to recharge the battery. I have switched it back to 120V mode and I can tell that as long as the SOC is same or less than the self-consumption threshold, it would pass-through from grid directly with grid wattage in same as AC watts out.
It seems that the Apex300 is pretty efficient when the inverters are on with no load (or in 120V pass-through mode), but when you apply a load, efficiency does drop quite a bit.
Yes, that 17W or 20W self consumption is just what the unit eats up having the inverter on and idle. When you ask it/them to do something then you also have conversion losses. The relative % of power loss also decreases as the load goes up. you use of very low load is why you see so much % loss. Most online double conversion UPSs operate at about 75-80% efficiency at or near full load. At low loads they can easily consume far more than the load they power. In 120V mode (or 240 using the right outlets only) when the grid input closely matches the output you have very little loss, in the neighborhood of that 17-20W number.
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Thank You very much Doug. What you are saying makes very good sense. I wish I would have found you earlier when I was doing my research. You have earned a sub for sure for your work. I put my Apex in the 120V mode 2 days ago, my wasted power overhead has dropped from 1500 watts to 800 watts per day which is a huge jump in efficency. That alone saves me 700 watt/hr day and allows me to run my fridge completly off of solar with no grid draw, sun dependent of course. I have to believe that some of these YouTube reviewers had early firmware revisions. Hobotech tested and did not see any difference in the 2 voltage modes. He always seems to do some in depth testing, either he tested incorrectly or his unit had early firmware. He was the reason I was just keeping it in the split phase 240V mode. I figured it was one less step to remember if I want to backfeed my house. Glad snowstorm started this discussion and got me looking at my own data.
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Wow, thank you so much! I may have to go watch that part of Hobo’s review again to see what he did or missed. Idle loss is just that, the unit idle, no load. Once you add load you also have conversion losses depending on where and how the power is flowing. A grid powered loss test with load should have quite different results in 120 and 240 if you have load on the left outlets, right outlets shouldn’t differ much. I’ve worked with big and small UPS systems for many years, which might be why I enjoy power stations so much.
I’m not on this forum much as I find it difficult to use. I’m mostly in the Bluetti Facebook groups and of course you can ping me in YT comments or this new channel community thing they have.
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