Hi guys,
My Sungrow solar inverter system is experiencing massive spikes only in the night.
It’s adjusted to stop using battery power when SOC reaches 50%. Multiple times at night, the inverter uses the grid to “i think float” the batteries with a huge amount of power “8500w at 230v grid power” south africa we are running 230v grid.
Please see pictures below.
I’m just wondering what’s the purpose of these spikes. Is it something to do with maintaining battery health?
That is strange. But it’s impossible to know without knowing more about your batteries. What type, brand, etc?
I do not think this has anything to do with battery health. Battery cell balancing to maintain health only uses a small trickle current.
It may also be a data glitch.
So am assuming it is also a Sungrow battery…SBRsomething or other.
That drop of SoC% to zero% is almost certainly something to do with it. If it had STAYED at 0% and then there was the grid spike I would have said it was the cause absolutely definitely.
I have had such a spike a couple of times when I deliberately drained battery as much as possible by setting offgrid backup reserve SoC to 0% and then running as many appliances as I needed to get the battery to 0% as a test of the dischargeable capacity; which is NOT the specified capacity by the way, I have since found out. The system will retain a “hidden reserve” as Sungrow call it, to protect the battery and to allow recharging to start, about 5%SoC. You can see this reserve % in the “Dashboard” battery data which will be different usually to the “Overview” figure - the hidden reserve will be the difference between the two.
If for some reason your battery was actually ZERO% SoC then it might have taken that 8kw from the grid to get going again. In my case it didnt do that until sun up though, was for a brief time then my PV took over.
However, it looks more like a loss of communications for a short time. I would think this is unlikely to trigger the grid spike, but it might I suppose.
If you use the Web based “app”, change the “curve” graph to “Summary”, and down load the data that includes those hours and see if the battery was truly discharged to 0%SoC. Even here, there might be 2 data sets, one from the battery and one from the inverter, I THINK. For the amount of energy discharged there are these 2 sets, but am not sure if there are also for the SoC% data.
When you say “adjusted to stop using battery power when SOC reaches 50%” I assume you mean this is where YOU have set your “Backup Mode” ie., reserve for offgrid emergency use. Seems quite high but obviously depends on your situation.
