Schneider xw6868 pro
- Thread starter latinhawk
- Start date
sunshine_eggo
Happy Breffast!
Speaking to off-grid:
I don't know the Schneider hardware, but going to battery would seem to be the norm. The PV would then dial on more power to maintain the battery at the float or absorption voltage, or whatever phase of charging it's in, so the power essentially comes from PV.
I don't know the Schneider hardware, but going to battery would seem to be the norm. The PV would then dial on more power to maintain the battery at the float or absorption voltage, or whatever phase of charging it's in, so the power essentially comes from PV.
Solar Guppy
Red Cobra Guppy
The XW doesn't pick and choose battery vs solar as its the same resource, the battery bank.
What you need to set is your solar charge controller float voltage in the ~54 volt so the energy will be uses as that is well above the resting voltage of the battery, which is ~51v when fully charged. If your solar charge controller is in bulk or absorb it will also be taking energy from the solar.
What you need to set is your solar charge controller float voltage in the ~54 volt so the energy will be uses as that is well above the resting voltage of the battery, which is ~51v when fully charged. If your solar charge controller is in bulk or absorb it will also be taking energy from the solar.
sunshine_eggo
Happy Breffast!
This indicates a problem with your system. There is rarely a reason to force bulk.
How could it possibly accomplish this?
It's an inverter. All it can do is convert DC to AC. If loads are needed, it has no other choice but to draw from the battery.
What normally happens is as I describe above, restated another way here:
Load increased
Inverter draws from battery
Battery voltage drops
PV charger sees battery voltage drop and outputs power to keep voltage at the set point.
In the above case, the PV is effectively powering the loads and keeping the battery charged.
If your system doesn't behave like this, it is not configured properly, you may not understand what's going on, or circumstances are such that PV is insufficient to power the load and keep the batteries charged.
"sun is out" doesn't mean there's enough sun to power loads and keep the battery fully charged.
A more detailed description of all of your system parts and what is happening may enable us to help you diagnose any problems.
JBertok
Network Engineer
In the XW Pro set the Grid Support Voltage to the desired float voltage of your batteries. The inverter will not pull the DC bus voltage down lower than that point unless Grid Peak Load Shaving is enabled.
In the chargers you'll need to increase the float voltage to a bit more than the Grid Support Voltage in the XW Pro. Start with +1V and back down from there making observation at maximum solar production with the XW Pro loaded. If you see your array voltage creeping up on the MPPT and output start to fall off, it indicates the MPPT is backing off.
Personally, at this point, I am keeping my batteries topped off with a Grid Support Voltage of 58.28V (FLA) and a MPPT Float setpoint at 53V. I also use Peak Load Shaving between 9AM and 3PM in case there are clouds; the idea to to end the solar day with topped off batteries but supply the loads during the day as need. (This is a Zero-sell configuration.)
Are you running your XW Pro(s) with the charger disabled? That would add another layer of complexity and prompt further discussion...
In the chargers you'll need to increase the float voltage to a bit more than the Grid Support Voltage in the XW Pro. Start with +1V and back down from there making observation at maximum solar production with the XW Pro loaded. If you see your array voltage creeping up on the MPPT and output start to fall off, it indicates the MPPT is backing off.
Personally, at this point, I am keeping my batteries topped off with a Grid Support Voltage of 58.28V (FLA) and a MPPT Float setpoint at 53V. I also use Peak Load Shaving between 9AM and 3PM in case there are clouds; the idea to to end the solar day with topped off batteries but supply the loads during the day as need. (This is a Zero-sell configuration.)
Are you running your XW Pro(s) with the charger disabled? That would add another layer of complexity and prompt further discussion...
JBertok
Network Engineer
A couple configuration question that will help pinpoint opportunities to adjust the settings:
1. Is this XW Pro Grid-Connected? (No/Yes with Net-Metering/Yes with Zero-Sell)
2. What is your battery chemistry and capacity? (FLA/AGM/LiFePO4/etc)
3. What is the intended roll of your batteries? (Keeping topped off available for outages/cycling daily to offset evening and night)
4. What kind of MPPT(s) are you using?
A summary of the grid situation and the ideal functional expectation for the equipment is helpful. I can almost just about promise you that your XW Pro will do exactly what you want it to, it's just a matter of settings.
1. Is this XW Pro Grid-Connected? (No/Yes with Net-Metering/Yes with Zero-Sell)
2. What is your battery chemistry and capacity? (FLA/AGM/LiFePO4/etc)
3. What is the intended roll of your batteries? (Keeping topped off available for outages/cycling daily to offset evening and night)
4. What kind of MPPT(s) are you using?
A summary of the grid situation and the ideal functional expectation for the equipment is helpful. I can almost just about promise you that your XW Pro will do exactly what you want it to, it's just a matter of settings.
My system is on the grid but the grid input is only used if my batteries are low. I operate as if I were off grid. The price per kWh is the same always. Currently it's around $0.30 per kWh. I have too separate battery banks. I have a bank of all eg4 lithium. It's 6 lipo4 batteries. 600 amps 48 VDC.
I also have a bank of AGM batteries as a backup. It's an either or situation. I always run on batteries. I'm using 2 Schneider 60 150 charge controllers.
I also have a bank of AGM batteries as a backup. It's an either or situation. I always run on batteries. I'm using 2 Schneider 60 150 charge controllers.
400bird
Solar Wizard
Sounds like you need to change settings.
Answer the questions in post 7 (specifically question 4) and post your settings for both the inverter and MPPT
Answer the questions in post 7 (specifically question 4) and post your settings for both the inverter and MPPT
GXMnow
Solar Wizard
- Joined
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Once the battery bank is fully charged, I see my XW-Pro and Victron charge controller doing a little dance. The wattage at the charge controller drops a bit below my load power for about 15-20 minutes. Once the battery voltage dips a little, then the power a the charge controller increases and sometimes will exceed the load power, then settles back down a little under again. It will never be perfect, but it is keeping the battery voltage at my absorb/float voltage as long as there is enough sun on the panels. As the sun goes down, the battery discharge rate increases as the charge controller can no longer keep up. That is all you can do. It is running on solar power only as long as it can.
With the Schneider MPPT units, it should behave a little batter than my mixed system with a Victron charge controller, but it will still work very similar. There is no separate solar energy bus. It is all working off of the 48 volt battery bus.
With the Schneider MPPT units, it should behave a little batter than my mixed system with a Victron charge controller, but it will still work very similar. There is no separate solar energy bus. It is all working off of the 48 volt battery bus.
sunshine_eggo
Happy Breffast!
Can't get much out of the posted information, but I'm seeing a 2 stage charge cycle (bulk, absorption). This typically does not include float and would explain why the batteries drain until they reach 51.2V where the MPPT then initiates a new bulk/absorption charge.
This supports my conclusion that the system is not configured properly.
Assuming LFP:
3 stage charging.
56.8V bulk/absorption
30-60 minutes absorption time
54V float
This supports my conclusion that the system is not configured properly.
Assuming LFP:
3 stage charging.
56.8V bulk/absorption
30-60 minutes absorption time
54V float
JBertok
Network Engineer
A little envious of your LiFePO4 bank!
Are you running open loop (voltage-based mode) or closed loop (State of Charge based mode with communications between an EG4 Communications Hub and Insight)?
I see the screenshot is for the XW charger setpoints, not the MPPT. Also 2-stage is the correct setting for the Inverter - leave that, otherwise the internal charger function of the XW will float the batteries forever and prevent the MPPTs from contributing.
Will need to know if you're in voltage or SoC mode for next steps in getting this sorted for ya.
Are you running open loop (voltage-based mode) or closed loop (State of Charge based mode with communications between an EG4 Communications Hub and Insight)?
I see the screenshot is for the XW charger setpoints, not the MPPT. Also 2-stage is the correct setting for the Inverter - leave that, otherwise the internal charger function of the XW will float the batteries forever and prevent the MPPTs from contributing.
Will need to know if you're in voltage or SoC mode for next steps in getting this sorted for ya.
sunshine_eggo
Happy Breffast!
@sunshine_eggo is just a guessing smurf... didn't realize that was for the inverter. Assumed it was the MPPT.
@JBertok and his avatar scream, "listen to me when it comes to schneider products!"
@sunshine_eggo fades into the background to listen.
@JBertok and his avatar scream, "listen to me when it comes to schneider products!"
@sunshine_eggo fades into the background to listen.
JBertok
Network Engineer
Like most other contributors here, I can offer only opinions and experience based on first-hand experience. I'm not always right, and when that happens please call me out because it helps me maintain the level of accuracy I prefer.
I think the xw6848pro.png and mppt2.png images/names transposed, but I got it... looking at them now....
I think the xw6848pro.png and mppt2.png images/names transposed, but I got it... looking at them now....
JBertok
Network Engineer
For reference, you're grid-connected, zero-sell, open-loop voltage-based, and prefer to draw down the batteries nightly with a daily recharge, prioritizing PV - then battery - then grid-consumption.
Starting with the XW Pro:
- Disable the internal charger if it isn't already. No need for high-dollar grid power to put energy into your cells.
(Note that the point where the XW Pro switches from AC Pass Thru to Load Shave Mode is based internally on 0.5V added to the charger's "Recharge Voltage" setpoint. This is poorly documented but relevant.)
- Under "Grid Energy Management (Grid Support)" the Grid Support Voltage needs to be equal to the desired float voltage of your batteries, which pulled from EG4 specs is 54V.
- "Grid Peak Load Shaving" should be enabled. The batteries need to be allowed to spend time at 100% SoC - this is when the BMS is doing balancing of the cells and when the BMS does capacity self-calibration so that the presented SoC is closest to accuracy.
- Under the Charger the "Recharge Voltage" setpoint is going to determine the lower limit of the battery bank discharge. For this we need to reference a LiFePO4 voltage vs. SoC chart since you're running in voltage mode. EG4 doesn't publish that (weirdly) but we can use a generic chart with matching chemistry, available on the forum. LiFePO4 voltage falls of more sharply after about 15% SoC, so that's an easy place to start. That's 51.2V on the chart, we subtract 0.5V for the setpoint, and so 50.7V can be entered into the "Recharge Voltage" field. Adjust higher for less depth of discharge and more available emergency reserve, lower for deeper discharge. (The difference between 100% SoC of 54.4V vs 15% Soc at 51.2V is only 3.2V across that 85% of SoC - so increment those adjustments very little.)
- Specify the Start and Stop times for Grid Peak Load Shave mode. This window of time specific when the inverter is allowed to pull the batteries below their Float Voltage (and also Grid Support Voltage) point. A period of time every day centered around your peak solar hours needs to be excluded from Load Shave mode to allow the batteries reach and float at 100% SoC for a while. The window you choose is going to be based on your load, available PV, and the recharge time. Load Shave Stop can be about 10AM where you're getting enough solar to power the load and recharge the batteries, and if reaching 100% SoC on average happens at 1PM, for example, the set Peak Shave Start to 3PM and that will give the BMSs 2 hours to do their balancing and calibrations.
- "Load Shave Amps" in the Grid Support menu should be set to 0A.
- "Low Battery Cutoff" should be 1V higher than the BMS LBCO, which EG4 says is 47-44V depending on Load. This needs to be high enough you're not getting nuisance warnings in Insight, but low enough that it never triggers a BMS shutdown. I'd start with 48V.
- Under Battery Settings, Set the Batter "Temperature Coefficient" to 0 as we do not want the XW Pro attempting to compensate for temperatures with LiFePO4. With that disabled you can still monitor battery temp if using a BTS or getting telemetry from the Com Hub.
MPPT 60 150 chargers:
- Bulk/Boost Voltage and Absorption Voltage are the same - set 56.2 for both. Yours is a little high per EG4 spec.
- Float Voltage should be 0.5-1.0V more than the setpoint for Grid Support Voltage in the XW Pro. It should be the lowest number that continues to pull full load from the PV in Float Mode to supplement the XW Pro loads. Start with 54.5V and raise or lower as needed by observing operations at full system load.
- In the Battery Settings, "Battery Temperature Coefficient" should be set to 0 to disable it.
- Your "Maximum Recharge Rate" is set to 99%, that should be 100%.
There are a few settings in there that will need operational observation to tweak toward working just right, but that should give you a good place to start. If an undesirable symptom or mode of operation pops up, we can address that directly.
Starting with the XW Pro:
- Disable the internal charger if it isn't already. No need for high-dollar grid power to put energy into your cells.
(Note that the point where the XW Pro switches from AC Pass Thru to Load Shave Mode is based internally on 0.5V added to the charger's "Recharge Voltage" setpoint. This is poorly documented but relevant.)
- Under "Grid Energy Management (Grid Support)" the Grid Support Voltage needs to be equal to the desired float voltage of your batteries, which pulled from EG4 specs is 54V.
- "Grid Peak Load Shaving" should be enabled. The batteries need to be allowed to spend time at 100% SoC - this is when the BMS is doing balancing of the cells and when the BMS does capacity self-calibration so that the presented SoC is closest to accuracy.
- Under the Charger the "Recharge Voltage" setpoint is going to determine the lower limit of the battery bank discharge. For this we need to reference a LiFePO4 voltage vs. SoC chart since you're running in voltage mode. EG4 doesn't publish that (weirdly) but we can use a generic chart with matching chemistry, available on the forum. LiFePO4 voltage falls of more sharply after about 15% SoC, so that's an easy place to start. That's 51.2V on the chart, we subtract 0.5V for the setpoint, and so 50.7V can be entered into the "Recharge Voltage" field. Adjust higher for less depth of discharge and more available emergency reserve, lower for deeper discharge. (The difference between 100% SoC of 54.4V vs 15% Soc at 51.2V is only 3.2V across that 85% of SoC - so increment those adjustments very little.)
- Specify the Start and Stop times for Grid Peak Load Shave mode. This window of time specific when the inverter is allowed to pull the batteries below their Float Voltage (and also Grid Support Voltage) point. A period of time every day centered around your peak solar hours needs to be excluded from Load Shave mode to allow the batteries reach and float at 100% SoC for a while. The window you choose is going to be based on your load, available PV, and the recharge time. Load Shave Stop can be about 10AM where you're getting enough solar to power the load and recharge the batteries, and if reaching 100% SoC on average happens at 1PM, for example, the set Peak Shave Start to 3PM and that will give the BMSs 2 hours to do their balancing and calibrations.
- "Load Shave Amps" in the Grid Support menu should be set to 0A.
- "Low Battery Cutoff" should be 1V higher than the BMS LBCO, which EG4 says is 47-44V depending on Load. This needs to be high enough you're not getting nuisance warnings in Insight, but low enough that it never triggers a BMS shutdown. I'd start with 48V.
- Under Battery Settings, Set the Batter "Temperature Coefficient" to 0 as we do not want the XW Pro attempting to compensate for temperatures with LiFePO4. With that disabled you can still monitor battery temp if using a BTS or getting telemetry from the Com Hub.
MPPT 60 150 chargers:
- Bulk/Boost Voltage and Absorption Voltage are the same - set 56.2 for both. Yours is a little high per EG4 spec.
- Float Voltage should be 0.5-1.0V more than the setpoint for Grid Support Voltage in the XW Pro. It should be the lowest number that continues to pull full load from the PV in Float Mode to supplement the XW Pro loads. Start with 54.5V and raise or lower as needed by observing operations at full system load.
- In the Battery Settings, "Battery Temperature Coefficient" should be set to 0 to disable it.
- Your "Maximum Recharge Rate" is set to 99%, that should be 100%.
There are a few settings in there that will need operational observation to tweak toward working just right, but that should give you a good place to start. If an undesirable symptom or mode of operation pops up, we can address that directly.
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