Can I use a LiFePO4 battery system with an Outback Radian 8048 inverter system?

[Rich V]

Hi All
My first post and I need some advice/help.

I have the following system:
Two Outback Radian GS8048 inverters (not the 8048A model)
Three Outback flexmate FM80 150VDC charge controllers
Two Outback GSLC load centers
Outback Mate3 system controller
Twelve Powersafe SBS 190f 12v lead/acid batteries (3 x 48v stacks)
8.25 KW installed solar panels.
The system is grid tied and batteries are only used during a power outage. The Radian system does use the batteries as a load stabilizer (correct term?) when in grid tied mode but the batteries spend 99% of time in float.

The batteries are at end of life and I need to replace them soon. I would like to use LiFePO4 based cells but don't know if my system can be adjusted for this battery type. I'm looking at the EG4 rack batteries or similar (SOK etc.) as possibilities. Want ~30KWH of storage.

I have read a few post here on similar Outback systems using these batteries but not with the Radian 8048.
So can I use LiFePO4 based rack batteries and if not what are my alternatives? I prefer not to use lead based batteries.
Thanks
Rich

 

[DIYrich]

Outback can handle anything from 12 to 60v.

 

[E. Cho]

The inverter doesn't care what provides the current, though with charging, a good inverter/charger providing clean pure sine wave power is best. Same for fossil fuel generators.

The FM80 can be manually adjusted for LiFePO4 Battery Bulk and Float voltage and reBulk settings and other options, though Bulk and Float and the system voltage (48V) are the main settings of concern.

As to what to set the Bulk and Float to, there are many different user opinions and "it depends" is sometimes in play as well, as in it depends on your battery use, desired battery longevity, recharging capabilities, sun hours, your OCD threshold ... There are many threads in these forums on "the best" LiFePO4 settings that you can read, as well as online. Other than the FM80, the other hardware that you listed doesn't really matter or care. Sadly, Outback, unless their forum or support has added something recently, is pretty much useless with LiFePO4 information. So don't sweat it, pick your Bulk and Float and reBulk or Tail Current settings in the FM80 and it all should just work as with Lead Acid, only better.

 

[Rich V]

Update
After speaking with Current Connected I ordered 6 SOK SK48v100-NCBT batteries. These are the "striped down" version without comm ports. These were recommended do to the Radian inverters having issues with the comms enabled SK48v100 batteries.
Apparently the Radians can exceed the short term amp draw limits on the SK48v100 causing shut down. The SK48v100-NCBT can handle higher short term loads do to a different BMS used in this model.

I'll update after the batteries arrive and I have them installed.

 

[Johneb]

Rich, I am in the process of putting together my system on paper before purchasing. I have decided on the Outback 8048a prewired system. Any chance you would have a diagram or pictures of yours. It might help me with some of my questions on what else is needed. ie dc cuircuit breakers, emergency shut off, etc.. Thanks.

 

[Rich V]

Rich, I am in the process of putting together my system on paper before purchasing. I have decided on the Outback 8048a prewired system. Any chance you would have a diagram or pictures of yours. It might help me with some of my questions on what else is needed. ie dc cuircuit breakers, emergency shut off, etc.. Thanks.

I had the system installed by a local pro installer so not much I can share that would be of help.
A lot will depend on what components you will use and if grid tied and/or if local codes & inspection is needed.
Best I can say is start a thread here and on the Outback forum https://forum.outbackpower.com/index.php?sid=9660d18c0c0d2e54a6269fb86ff2c3f5 detailing what you want for your system. Outback tech support is also very helpful so ask there as well.