Aleksey

Hello. I have Voltronic InfiniSolar v4 (3.6KW) inverter, which is 48v inverter. 4x AGM batteries are attached to it (65Ah each). Inverter is set to SUB mode (Solar -> Utility -> Batteries), so it shouldn't drain the batteries unless both Solar and Utility is unavailable. But what I see is: That's the battery capacity data from the inverter, for two days. But I get almost the same picture for each sunny day - after 6am pv starts to deliver enough energy for charging the batteries up to 100%, then the capacity starts to go down very quickly, down to 60% before the next sunrise. And so on. For the same period, the battery discharge current graph and grid voltage graph are: I.e., during these periods when the capacity drops down, the grid is always available, and the battery discharge current looks like it's almost always zero. But yet sometimes there are strange spikes like the one on the graph. Plus the inverter reports discharge current as integer in Amps, therefore I suspect if it was able to report it as a float, it won't be zero, looks like the real discharge current is not zero, it's somewhere between 0A and 1A. I expected that in SUB mode the only thing that should drain the batteries is their self-discharge, which should be small enough for AGM, enough to have decent capacity even after a month without charging them. But in reality, after a couple of cloudy days I have the following picture: Yeah, eventually down to zero. Very disappointing. Does anyone know whether it is "normal" for inverters? Or am I having an issue with my hardware/batteries (what to check is that case)?

I've updated my location in the profile.

@TaliaB, I think you gave me the explanation! Thanks! Now, when you asked to look at both generation and consumption, everything becomes clear: When (active power + charging power) is more than the generated power, the generation graph is "smooth", otherwise throttling happens, which, on the graph looks like chaotic hops. I thought it's an issue with my pv or inverter, but everything is fine, only a lack of experience from my side. Thanks.

@TaliaB Sure. I have 10 panels, all of them connected sequentially. Each panel has the following specs (I couldn't find specs in English, the below is a translation): Power: 100 w Type: Monocrystal 75x166 mm Number of elements: 36 (3x12) PV element: 9BB (9 bus bar) Idle voltage: 24,25 V Working voltage: 20,40 v Short circuit current: 5,25 A Working current: 4,90 a Max voltage: 1000 V Module efficiency: 19,23 % Element efficiency: 21,30 % Number of diodes: 1 The panels are looking at South, almost. They are sitting on the wall, so the tilt, I suppose, is 90 degrees. Note that I'm located at the North hemisphere, therefore now it's Spring for me and I'm moving towards Summer The Sun is already very hot, plus snow still covers everything, it reflects a lot of sunlight. When I'm standing near the panels, it's too hot and bright there, very hard to be there without sunglasses. The inverter reports pv voltage is around 230 V: Btw, when the inverter reports that the generation is 0w, at the same time the voltage is still as usual.

Hello. I have inverter "Voltronic InfiniSolar v4" and quite new (one-year old) pv panels that can potentially generate 1kw. At first, everything was fine, at sunny day they indeed were able to produce ~800w constantly for several hours. But, recently I started to observe the following picture (today's example): Today is a perfect sunny day with clear sky, no shadows over the panels. As you can see, at first the Sun is going higher as well as the generation. But then, instead of going up to the maximum generation, it starts to chaotically jump up and down, so that one second it shows 500w, the next second it may be even 0w (!) and so on. All that results in a very poor average generation, so that I receive only ~100-150w in average from 1kw panels in a sunny day). Another strange thing is that at cloudy days the chart is way "smoother": I.e. although the generation is quite low, but there are no these chaotic "hops". I'm pretty new and have no experience in that area, I have tried to search for similar situations over the internet, but with no luck. What should I check? Where to start diagnosing the problem? What could be the reason?