Well I don’t have AC out connected at all so it’s dissipating that 104W into thin air. I considered them internal losses so 18.56% should still be accurate. I also doubt this is a temperature issue, the inverter is in my basement where it’s around 20C, even now in summer. The losses are pretty consistent btw, I checked multiple power levels.
I’ll just have to look into other inverter brands as this is unacceptable. Thanks all for your suggestions and replies.
I have a second hand but as good as new MP2 5000/48 on sale if anyone is foolish enough.
Well, if those heat pumps are the culprit and that customer decides to go ‘Chinese’ , I’m pretty sure these chinese machines won’t last as long as the victrons would. I imagine it won’t be too easy for those end stage hf pwm mosfets building the ‘not so sine’ wave to actually match the pf on the line. Just speculating here but it seems common sense to me that the low frequency toroid transformers will have much less trouble to survive, albeit at an efficiency penalty indeed.
I can’t comment on other chinese brands, but we transitioned out of GW and into Victron for that reason and a few others;
- the GW inverters had a fault rate of around 15%, so far (5 years) the Victrons inverters haven’t had a single failure.
- the GW zero load power is terrible, we had many customers wondering why they had only a fridge on overnight and lost over a kwh. The culprit is the ~78 watts of idle load losses in the growatt, its a very very expensive unit to keep running. The equivalent EasySolar is 18w. Many users resort to turning them off overnight.
- The old spec sheets used to say 50w-80w idle consumption, new GW SPF spec sheets don’t even report the idle consumption.
- The PCBs are not protected from moisture at all, and the fans run 24/7, and so board corrosion kills many of them before they even get through their warranty. Especially causing things like false over-temp alarms.
- Search the forums for “Growatt idle power consumption” - many many complaints. In a grid connected situation, that’s maybe fine to be ultra low efficiency, but off grid its a (literal) show stopper.
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I’m not too familiar with the solar / hybrid inverter market. Is there any brand that stand out in a positive yet still affordable way, that could compliment a 48V Victron MP-II as a secondary AC source to sell energy back to the grid (through the MP-II on AC-out 2) from a HV DC source (EV battery)? I have a very specific use case for such a thing to do occasional full capacity tests on a single string of modules. Would not even need to be able to charge as that will be prepared in a parallel top balance configuration (12S Li-ion), just need to dump all that energy back to the grid in 96S config for a final (comparative) capacity measurement.
I exported the “production report” from VRM for june, and the discharge/charge figures under battery give me a 60% round trip efficiency. I understand where that comes from, with relatively low consumption and a three-phase system’s idle consumption, and high charging power from the AC coupled PV, but still, that is a sad number.
My next addition to a personal system will be a Deye, after some good reviews from people (installers) i trust.
I use MultiPlus-II 3000VAs to export to the grid on a regular basis. I’m running them at ~80-85% capacity and reach a bit over 90% efficiency. You’ll get nuch better numbers if you decrease the grid set point a little bit, maybe to -4000W or -3800W.
Wow yeah that…phew. Look at my home system.
Took some time, and money, to get here, but it is possible.
@Jalle19 I personally never mock around with that setting. Always use the default value.
@RoarPowerNZ No Deye here. Seen badly broken inverters. Even on YouTube.
Those numbers Growatt state can be achieved. But only from PV to grid, and only when the PV voltage is above 350Vdc on a 240Vac network, or 560Vdc on a 400Vac network. Or simpler put: higher than the peak to peak voltage of the AC you want to get out of the output.
The same counts for battery inverters, as long as the DC voltage is higher than the p-p voltage you will get big number efficiency.
Inverter design is a combination of compromises.
- The MultiPlus II has a low voltage battery system (less issues with isolation of bare copper. Trade off: more copper).
- It has a transformer step up (galvanic isolation of DC and AC and little to no issues with EMC. Trade off: weight and less efficient).
- The Victron ecosystem is fully customizable (you can program your system exactly to tailor your needs. Trade off: you REALLY need to know what your getting into for both hardware and software. Oh jeah: and regulations!).
And system efficiency is not only dependent on the inverter, your batteries have losses and the wiring also has influence. So to blatantly blame Victron is just wrong.
Like others also mentioned above: how do you measure these values. MID grid meter (ac) and Smartshunt (dc)? Or OneHungLo WiFi grid meter and the shunt from the battery?
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I just went with what the Cerbo told me, and I could feel the heat on the metal case so have little reason to doubt that 81.5 efficiency number is correct. My Growatts are pumping 5kW all day and are cold, and silent. You’re absolutely right though, the battery itself could have losses as well - it was at 39C after that discharge cycle. I probably don’t even make 70% for round trip considering all that.
You’re right about the peak AC ideal voltage as well, no idea why they even make these 48V batteries, should indeed be 350ish.
I have a cheap kW(h) meter on order from Ali, I’ll know for sure then, but it sure doesn’t look good.
I kind of do blame Victron, they advertise up to 95% and I barely get above 80 in the real world.
Learned some new things from this topic today, thanks guys. And still interested in recommendations w.r.t. solar/hybrid/HV inverters but don’t want to hijack this topic (too much) for that.
Which is the price?
And where are you (as in country)? To calculate the shipping cost…
Thanks!
That’s because they are converting solar to high voltage DC (400VDC), which is near 98% efficiency as any HV MPPT.
Then from 400VDC is easy to do it 230VAC, with almost the same efficiency.
This is why they are running (almost) cold.
Or, if you are converting from battery to AC, then also a HF DC/DC converter, from 48VDC to 400VDC (and then, as above, from 400VDC to 230VAC) is much more efficient than the direct type of DC/AC converter MP2 is using. Not to mention losses much bigger in MP2 type of transformer than a HF transformer as used on Growatt.
If you don’t like the MP2, then, after you sell it (to me), you can buy a Multi RS, which is Growatt like from HW topology point of view.
LE:
Sorry, later seen that David above told you about the same thing…
Sometimes is easy to miss things on such long posts, this is why in another place I’ve mentioned the Summary feature of the forum that was removed…
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Same question
I’ll make you that deal for our MPII5000GX any day, will pay for shipping too 
Got it for 700, you can have it for 650. Not even one week old. I’ll cover shipping if you’re in Europe or I’ll bring it to you personally if you’re in Belgium or Netherlands.
It’s a very inefficient and noisy inverter though…
That’ll be the PMP482505012 from NKON.
Also. You are basically selling it without warranty. Since the warranty is not transferrable, So if you can’t bring it back, understandably with that 5MWh that you pushed into it…then I wouldn’t be surprised that people pass on the offer.
Thank you for the offer but I’ll need to pass on that.
5MWh that I pushed into it? I wish, or probably not cause I just got a tiny fraction out of it. They offer 5 year warranty on their devices, and I haven’t registered for it. Not intending to either.
That’s ok Jan, I’ll jut have to suffer this ugly duck myself in my inverter farm.Really just investigating the proper setup now, but sure enough, the MP2 won’t be part of it.