You’re hinting at what I think is one of the most important specs in a power station, and yet largely unreported and nearly impossible to discover without buying one and testing it yourself. Basically: how much power does it consume with the inverter turned on but at zero load? Some are worse than others, and some are downright terrible. For instance, I did my own rough-and-ready measurements on both the ecoflow river 3 plus and on the Dgi Power 1000. With no AC load but with the inverter turned on, the river 3 plus consumes around 5-6 watts. Compared to most power stations, I’d rate that pretty good. Assuming it charged beforehand to its full 286wh capacity, that means it will drain itself down to zero capacity in around 50ish hours doing effectively nothing. Why is this worth knowing? Well, I figure any load it might support would be subtracting from that number, which is the baseline overhead.
For the DGI, though, it’s far worse: I measured its overhead at a constant 35w, which quickly adds up. In the same scenario, doing the same amount of nothing, it will flatline is about 29 hours, even though it has a 1024wh battery (or about 3-4x of what the river 3 plus has).
Who cares? Well, if you’re using it to run a refrigerator or a gas furnace, for example, which may be running on average, say, around 10 to 20 minutes out of any given hour, all that overhead severely cuts into how long you can run it. This latest generation ecoflow appears to have some self-scheduling abilty, which might allow you to automatically turn the inverter on and off according to a schedule, to avoid that waste, but I haven’t yet done that experiment, so I can’t say for sure.
As you probably already know (but I’m mentioning for the benefit of any other readers who may not), this fits a larger pattern, which is that, in general, the bigger the inverter, the bigger the overhead. For this reason, one should want to avoid big inverters, unless you really have a need that requires it. Of course, it probably doesn’t matter if it’s just a 3D printer UPS, but, at least for me, anything I buy has a secondary purpose as emergency backup, like for what those poor devils experienced with Hurricane Francis in September 2024. Hurricane, tornado, earthquake, polar vortex, whatever. When those happen, even if you have electric generators, you probably only have so much reserve energy, and maybe can’t get more, so you want whatever you happen to have on hand to last as long as possible.
Everyone seems to agree that the Victron inverters have the least overhead, which can be as little as 1 watt on the smallest Victron inverter running an economy mode. If anyone reading this knows of an even more efficient brand than Victron, please do post.
