Open loop applications for the Powerflo16

[Kent0]

Is open loop charging of the Powerflo16 permitted? I have a customer with a Outback GFX3048 that needs new batteries. The Powerflo16 would be an easy substitution for 8 L16 AGM batteries.

[FNG]

Yes Open loop is acceptable as well

[mvrck]

I made this chart over time that includes the average of most LiFePO4 batteries and I have used these settings found in the LiFePO4 Column on the Powerflo16 on both Outback Radian and XW6048 in open loop.

Let me know how you have setup your Outback and other open loop systems.

[ClassicCrazy]

You can't really tell the SOC of a lithium battery by it's voltage.
It is way too flat of a curve and is going to be under load or charging and not just resting voltage.
The only way to know it's SOC is using some device with a shunt like the Whizbang or another that will count everything going in and out and reset to 100% at the top for whatever voltage you think is best. I use 55.2v , others go higher up to 56v , etc. It really depends on the time you want it to take and balance settings of a particular bms.
Larry

[mvrck]

I absolutely agree that a chart that correlates SOC to voltage isn't accurate (just like it isn't on Lead batteries) and I also agree that the system should have a current meter like WhizBang, or the case of Outback, the FlexNET DC. In the end, You still equate 100% SOC to a voltage and I also prefer 55.2 as 100% full.

The charge controller and inverter all use Voltage for many settings and the chart above was just a way to enter some value to have the system operate in Open Loop with some appropriate levels. Even in open loop, it's good to have another device that can display the batteries internal SOC data, like an old laptop or a CAN / RS485 meter or Cerbo GX, etc.

A future project is buy a JBD BMS Smart LCD RS485 Display to see if I can provide a basic display for a more detailed status for some customers that still have older inverters.

[ClassicCrazy]

I absolutely agree that a chart that correlates SOC to voltage isn't accurate (just like it isn't on Lead batteries) and I also agree that the system should have a current meter like WhizBang, or the case of Outback, the FlexNET DC. In the end, You still equate 100% SOC to a voltage and I also prefer 55.2 as 100% full.

The charge controller and inverter all use Voltage for many settings and the chart above was just a way to enter some value to have the system operate in Open Loop with some appropriate levels. Even in open loop, it's good to have another device that can display the batteries internal SOC data, like an old laptop or a CAN / RS485 meter or Cerbo GX, etc.

A future project is buy a JBD BMS Smart LCD RS485 Display to see if I can provide a basic display for a more detailed status for some customers that still have older inverters.

If you have batteries with Pace BMS type you can  use an esp32 or raspberry pi to get all the batteries in series with just one battery connected. It will show all 16 cells in every battery .
I also use a victron smart shunt which is easy to bring into Home Assistant .
The other monitoring I have been using Shelly EM ( just got the EM3 Pro ) and also I use Peacefair PZEM -017 for DC or PZEM - 004T for AC . Both of those peacefair are supported by ESP32 flashed with Tasmota .
Here is the pace bms project which I have used for years ( and also the Classic project )
https://github.com/ClassicDIY/PylonToMQTT
Larry

[karlsolar]

 does the powerflo 16 have an inverter pre-charge built in or do I need to do a resistor for the Radian or other outbacks?
also, is there a source for the settings for the powerflo 16 for using older non communicating CC's (FM-80, FM-100, Classics)?  bulk V, absorption V and Time, float V, refloat V?

Other Thread started. 
Quick add: they don't seem to have a pre-charge circuit in them. 

[ClassicCrazy]

I just saw this on Midnite page for open loop charging specs.
It may have been recently added
Absorb Voltage 56.4V, Absorb Time 5 minutes, Float Voltage 54V
https://www.midnitesolar.com/productPhoto.php?product_ID=768&productCat_ID=61&sortOrder=1

Larry

[mvrck]

I did see that recently as well.

56.4 / 16 is 3.525 V per cell. That seems like normal if not on the high end of other LiFePO4 battery makers. The 5 minute Absorb seems short, but I don't know the actual voltage that the MidNite Active Balancers start working. Since Float is 54, maybe that is the magic number. I wonder what the time needed is for proper active balancing?

Speaking of open loop, I made a video adding 3 Powerflo16s to a Radian. I made comments about voltage settings, etc. Let me know what you have set for your Outback equipment with MidNite batteries.

https://youtu.be/AwoaTZtHMjU?feature=shared

[ClassicCrazy]

I did see that recently as well.

56.4 / 16 is 3.525 V per cell. That seems like normal if not on the high end of other LiFePO4 battery makers. The 5 minute Absorb seems short, but I don't know the actual voltage that the MidNite Active Balancers start working. Since Float is 54, maybe that is the magic number. I wonder what the time needed is for proper active balancing?

Speaking of open loop, I made a video adding 3 Powerflo16s to a Radian. I made comments about voltage settings, etc. Let me know what you have set for your Outback equipment with MidNite batteries.

https://youtu.be/AwoaTZtHMjU?feature=shared

if you mean that the balancing starts at 54v ?  No it would never be that low - it could make the balance worse.  Usually balance starts at anywhere between 3.4 to 3.5 - seems like every battery manufactuer does it a bit different. If you want to see what Gobel Power 280 ah  has their settings at for Eve cells, here is what they are for the main bms and for the additional 4 amp active balancer.
What you see below is that the bms will balance at 3.40 but only with a 30mv differential  . The active balancer will start to balance at 3.45v until a 3mv differential and will stop balancing at 3.4 .  I think I have that interpreted correctly . Also it is set to show 100% SOC at 55.2v and 5 amps .
Larry

[mvrck]

Great information! Thank you.ill fold this into the big spreadsheet of batteries.

I connected the Powerflo 16 to a Schneider XW system with the InsightHome internet gateway. The battery reported as a PolyonTech battery with an operating range of 46.5 to 57.6V, 200A charge and discharge.  Seems like the Powerflo fits in the usual guidelines for 16-cell LiFePO4. That's good news.

So far they have been working great.

[brett]

Does float time matter for Powerflow 16 in open loop?

Using the settings now posted on the website:
Absorb Voltage 56.4V, Absorb Time 5 minutes, Float Voltage 54V

thanks

[ClassicCrazy]

Does float time matter for Powerflow 16 in open loop?

Using the settings now posted on the website:
Absorb Voltage 56.4V, Absorb Time 5 minutes, Float Voltage 54V

thanks

Once the batteries are at their absorb setpoint, they stay at that voltage for the absorb time of 5 minutes. Then they go to float for the rest of the day . The next day the bulk to absorb to float will start again. The float setpoint is at a voltage that the batteries won't charge or discharge but the controller will be able to make power directly for the loads.  So float time is whatever is left after the Absorb cycle is complete.
Larry