EG4 6500EX PV and Load Values

[RoySalisbury]

Has anyone else noticed large differences in the power values reported by the EG4 6500EX?

I would assume that the PV Power (power coming in on all MPPT), the Power Load (the amount of power being used by the inverter) and the Batter Power (power going in or out of the battery bank) would reconcile to a relatively close value. But this is not what I am seeing. I see a difference of nearly 600 watt between what is reported by the PV and what is being reported as the "load", even when the battery shows "0" (in or out).

Here is an example.

PV: 1078
Load: 2655
Battery: -2376

So the inverter has a load of 2655 watts .. the PV is providing 1078 watts .. a 1577 watt difference. So why is it pulling 2376 watts from the battery? Thats 799 watts unaccounted for. Even with the overhead of the inverters at a rated 90 watts each (2 in my case), thats 619 watts.

I have a Victron shunt now installed between the inverter and the battery bank so I can get an accurate battery load and its not even the same as the inverter reports. I get a 345 watt difference between what the EG4 reports and the Victron. If I take the readings direct form the BMS, its within 45 watts of the Victron (an acceptable difference).

Are these 6500EX devices that inefficient? That could add up to nearly 4Kw per day. And honestly, I have seen the difference much higher when the PV has a higher input load.

 

[Lt.Dan]

Even with the overhead of the inverters at a rated 90 watts each (2 in my case)

90 watts is IDLE consumption, you are not at idle.

I have gone through the exact same thing, except with the MPP Solar models, you are experiencing 2x things from what I have found;

1) Efficiency loss
2) A budget inverters poor ability to report accurate data

 

[Adam De Lay]

1) Efficiency loss
2) A budget inverters poor ability to report accurate data

Agreed

I’ve seen the same thing with my 6500s. I’ve always used a smart shunt to keep track of my battery banks and have just resigned myself to the fact that these units are cheaper and less efficient.

 

[RoySalisbury]

2) A budget inverters poor ability to report accurate data

I'm going to have to agree with this as the reason as well. Wonder if there is a shunt that will work for direct PV measurements. Would be nice to actually know how much power I am really making without relying on just the battery shunt (since thats not the whole story of the power usage)..

 

[Lt.Dan]

I'm going to have to agree with this as the reason as well. Wonder if there is a shunt that will work for direct PV measurements. Would be nice to actually know how much power I am really making without relying on just the battery shunt (since thats not the whole story of the power usage)..

Right off the top of my head, you can use Optimizers. Not a very cost effective way to just monitor how much PV is coming in, but atleast they serve more purposes.

 

[Zapper77]

What firmware version? The newest firmware made huge improvements when reporting numbers.

 

[RoySalisbury]

What firmware version? The newest firmware made huge improvements when reporting numbers.

I'm using the latest firmware for both the display and inverter on both units. I actually just upgraded to them about a week two weeks ago.

Roy

 

[Zapper77]

I'm using the latest firmware for both the display and inverter on both units. I actually just upgraded to them about a week two weeks ago.

Roy

My units appeared to be accurate within one amp. Inverter reported 40 amps going to the batteries and my clamp meter would show around 39 amps.

 

[Zapper77]

My units appeared to be accurate within one amp. Inverter reported 40 amps going to the batteries and my clamp meter would show around 39 amps.

I'll add that I use actual consumption plus 10% and don't forget to add on idle consumption (around 1.5 kWh each per day)

So if I consumed 20 kWh in a 24 hour period...I would need 25 kWh of solar to break even.

 

[RoySalisbury]

I'll add that I use actual consumption plus 10% and don't forget to add on idle consumption (around 1.5 kWh each per day)

So if I consumed 20 kWh in a 24 hour period...I would need 25 kWh of solar to break even.

Its both the > 10% efficiency loss and the high idle consumption for these devices. My older Outback system was only about 2%-3% total. You get what you pay for I guess. I've compensated by adding more panels. I may try to put in one of my Outback FM80 charge controllers and see how it compares to the built in charge controller.