February 16, 20251 yr my Solis s6 pro is having a lot of difference between charged and discharged units, like 64% efficiency, I contacted my vendor and he says to first make sure that there isn't a problem with my new dyness bx51100 battery and check how much efficient dyness batteries are and later they will check the inverter. so if anyone is using a dyness battery kindly share your charged discharged graph so that we can compare.
February 17, 20251 yr Already answered you in one of your 5 threads where you were spamming with this same question. Since I see that those threads got deleted by the moderators because of your spamming, I will make it short this time: This is NORMAL. Every inverter has internal self-consumption, and they normally try not to report it. For these small inverters it's around 2kWh per day just to keep the box runnnig and fans blowing. Therefore, if you charge 5kWh in a day but the inverter consumes 2kWh, then you have just 60% efficiency. How to improve it: Charge and discharge 100kWh in a single day and you will see more than 90% efficiency (100kWh from PV vs 2kWh of inverter's self-consumption). Of course, in order to be able to do it, you need big battery, big AC loads and many kWp of PV modules. Clear? Edited February 17, 20251 yr by Youda
February 17, 20251 yr 47 minutes ago, Youda said: Already answered you in one of your 5 threads where you were spamming with this same question. Since I see that those threads got deleted by the moderators because of your spamming, I will make it short this time: This is NORMAL. Every inverter has internal self-consumption, and they normally try not to report it. For these small inverters it's around 2kWh per day just to keep the box runnnig and fans blowing. Therefore, if you charge 5kWh in a day but the inverter consumes 2kWh, then you have just 60% efficiency. How to improve it: Charge and discharge 100kWh in a single day and you will see more than 90% efficiency (100kWh from PV vs 2kWh of inverter's self-consumption). Of course, in order to be able to do it, you need big battery, big AC loads and many kWp of PV modules. Clear? I am not clear about how efficiency is measured. I look at the percentage of power generated over power consumed, but that's not the same thing. Is it the round trip? So much PV comes in, and then so much comes out of the inverter when the battery discharges?
February 17, 20251 yr Hi@Bobster. you are missing important part of the original posts and threads (that were deleted by moderators because of excessive spamming I suppose): There was a screenshot of the inverter's LOG, where each day it was reported roughly 5kWh as charged in the battery and 3kWh as discharged from the battery. Efficiency was calculated as the ratio between charged/discharged. All these inverters are hiding their own self-consumption and instead of the real measuring on all the possible points, they measure just on a few of them and then calculate the other values with the use of constants. For example: Measure incoming PV power, integrate over time for kWh. Measure outgoing AC, integrate for kWh. The difference between incoming PV kWh and outgoing AC kWh is reported as charged in the battery. Since there is 80W of idle self-consumption, it's roughly 2kWh per day that get's lost in these calculations. I'm pretty sure that the real lithium battery efficiency in this case is way over 95%. That would be visible on the numbers directly from BMS. Numbers from the inverter are more about whole system efficiency, which in this case is really 60% roughly, due to the low ratio of energy generated, stored and consumed when compared to energy needed for just idling the inverter.
February 17, 20251 yr 1 minute ago, Youda said: Hi@Bobster. you are missing important part of the original posts and threads (that were deleted by moderators because of excessive spamming I suppose): Yes. I remember the matter of efficiency being mentioned in one of the threads. I did some searching for that word yesterday, and could not find those posts. The only possibility was that the threads had been deleted.
February 17, 20251 yr Just now, Bobster. said: The only possibility was that the threads had been deleted. Yes, there were 2 or 3 additional screenshots from the inverters APP that clearly showed what's going on here. I elaborated on it for half an hour to explain. Shame that our friend spammed so hard that it got all deleted 😐
February 17, 20251 yr 5 minutes ago, Youda said: I'm pretty sure that the real lithium battery efficiency in this case is way over 95%. That would be visible on the numbers directly from BMS. Numbers from the inverter are more about whole system efficiency, which in this case is really 60% roughly, due to the low ratio of energy generated, stored and consumed when compared to energy needed for just idling the inverter. It did seem likely to me that the OP and the people whose systems he was comparing his own to were not using the same method of measuring efficiency.
February 17, 20251 yr 19 minutes ago, Bobster. said: systems he was comparing his own to were not using the same method of measuring efficiency. AFAIK, it was Solis + Dyness vs. Solis + Pylontech. Presented efficiency was different, but really terrible in both of the cases. You asked there why is the OP comparing systems that have different components, loads, number of panels etc. Which was a valid point. The difference in those efficiencies was caused by the fact that one system used and generated 5kWh per day, while the other 7kWh per day (or something like that). Should we get a comparison with the system that generates and uses 100kWh per day, the presented efficiency will be superior Should we use a different method to calculate battery efficiency (for example using values from the BMS), the lithium efficiency will be superior too. Edited February 17, 20251 yr by Youda more examples
February 17, 20251 yr Author @Youdahi @Youda ! thank you so much for the explanation you are a true genius, means alot to me , I am sorry for the other day , I was just a newbie on the platform and was learning to interact, I apologize and I am still learning about the use of the platform. thank you for your time. If you want to see the other screen shots , here they are
February 17, 20251 yr 48 minutes ago, faizan1111 said: you are a true genius Yeah, that's what I hear all the time. Mainly women are telling me this
February 17, 20251 yr Author ok @Youdahere are my calculations for December 2024 SS attached inverter self consumption from battery for 13 hours a day 60w×13hours×31days of December equals 24kwh bms consumption lets assume 30w for 31 days of December 22kwh 107+24+22 equals 153kwh Total charged 159 kwh that makes it 96%roundtrip efficiency. correct me if something wrong.
February 17, 20251 yr That looks reasonable to me! BTW: BMS boards normally take just under 5W or so. Except for the time when they are balancing. Hybrid all-in one inverters consume at least 60W when idle, but significantly more (150W+) when the PV production is high. You can notice that the inverters got very hot (and even start fans) when under high AC load or when the incoming PV power is high too.
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