EASun Igrid VEII 5.5kw inverter draining battery all the time

[fixvid]

Hi, i am testing EASun Igrid VEII 5.5kw inverter with 5KWh of li-ion storage.

The problem is that when inverter is in hybrid mode and it's supposed to suck energy from grid without getting the battery involved, it slowly discharges the battery overnight.





The voltage drops almost 2v after 15h which is alot for a battery this big.

The inverter seems to work ok in "battery mode" and discharges the battery accordingly, but i have a feeling that the battery is discharging faster than it should even in this mode.

Did someone encounter any 'parasitic' discharge current on the inverter ?

[Ampster]

Do you have any kWh data about how much that discharge is? What is the voltage of the pack? Is any of that voltage drop the normal settling after a charge? My Outback Skybox has an overhead of 300 Watts but it uses the grid for that.

[fixvid]

The battery is a 48V 6.2KWh Li-Ion battery. I disconnected the battery for 10h and the voltage stayed exactly the same.

I dont know the exact amperage draw but as the graphic shows it's a constant value.

My knowledge tells me that in hybrid mode power is consumed only from panels and grid. The battery is still draining even after reaching low voltage cut off of 44V. What is more disturbing is that the SmartBMS doesn't show any discharge current. I will have to buy a clamp meter to see how much current is drained from the battery.

What do you mean by 300W over head? i know that an inverter consumes around 50W in idle.

[Ampster]

The battery is a 48V 6.2KWh Li-Ion battery. I disconnected the battery for 10h and the voltage stayed exactly the same.

I dont know the exact amperage draw but as the graphic shows it's a constant value.

If the vertical axis is Amps that looks like one Amp which would be over 1kWh per day. It does look like it goes off and on. That might give you a clue if you can correlate those times with any loads.

My knowledge tells me that in hybrid mode power is consumed only from panels and grid. The battery is still draining even after reaching low voltage cut off of 44V. What is more disturbing is that the SmartBMS doesn't show any discharge current. I will have to buy a clamp meter to see how much current is drained from the battery.

What do you mean by 300W over head? i know that an inverter consumes around 50W in idle.

Overhead is another term for idle consumption. 50 Watts is the same as one Amp at 50 volts so that is probably what you are seeing. I have no explanation for why that would be intermittent per your graph. With a 5 kWh battery it should be depleted in five days or less from that idle consumption.. The solution is to turn it off or find a charging source to cycle it up occasionally..
If the battery is still draining after low voltage cutoff value then the cutoff is not working or something is wired wrong. A possibility is that if it is on the inverter it would prevent loads from further drawing down the battery but not drop out the idle consumption. Typically if a BMS is activating a low voltage cutoff it would disconnect the inverter.

Do you know if the low voltage cutoff in the inverter or the BMS?

[fixvid]

The inverter has 2 LVC, first one is set at 44V and it's functionality is to deacticate battery mode and activate hybrid mode which in teory means no more battery discharging.

Second LVC is more like a real cut-off and it's set at 40.9V. I don't know what event will trigger this LVC beside generating an error event with "battery low voltage" message and if it will still drain the battery under this voltage. It didn't have the chance to discharge so much until now.



Let's say that usable capacity is around 4KWh. If we take into account that inverter consumes ~50W, it should deplete the battery in 3.3 days. I have a feeling it doesn't last this long.
If i do some rough math and every 8h discharge the battery 1v (as the graph shows) the battery should be depleted in 2.6 days. Not far from theoretical 3.3. 50W consumption feels a lot for an inverter.

I still don't understand why there is no current draw reading on the SmartBMS app when inverter is idle or sucking energy from grid.

[Ampster]

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I still don't understand why there is no current draw reading on the SmartBMS app when inverter is idle or sucking energy from grid.

The BMS should show current in and out of the batteries. I don't know anything about the SmartBMS, I don;t think the BMS would show anything coming from the grid unless that energy is going into the batteries. If the inverter has a shunt or other current measuring device then it may show energy coming from the grid. I am also not familiar with your inverter. What does the manual say about data?

[fixvid]

I mean the SmartBMS shunt doesn't show any current draw when the inverter is drawing this "50W' idle power. I need a clamp meter to see at least what is this current value.