How are you charging your SimpliPhi battery?

A place to post images and descriptions of your OutBack Power System

Moderators: OutBack Moderator Team, OutBack

Post Reply
raysun
Forum Emperor
Posts: 4624
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 48v)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

How are you charging your SimpliPhi battery?

Post by raysun »

The SimpliPhi battery is a new, and very expensive, player on the solar + storage scene. There's a small, but growing, trend toward adopting this LiFePo4 battery in Outback systems. The current Outback equipment is suited to employing a LiFePo4 battery.

Outback and SimpliPhi have done a good amount of integration testing, and both companies have published integration guides. It's good to have the "care and feeding" information detailed such that the battery can be properly deployed and maintained. That's not to say there isn't a degree of ambiguity in the guidance. For example, both company's guides have contained no less than three different target voltages and charging times for the same battery model. After a good deal of research, I've come to the conclusion the divergence has less to do with inaccuracy in publication, and more to do with the nature of LiFePo4 battery physics. There seems to be more than one way to skin the proverbial cat. Which charging parameters will bear the best results in terms of useable capacity and battery longevity remains to be seen. In any event, it has the potential to be an expensive lesson.

Since we are very early in the learning curve, I propose we who are using SimpliPhi batteries pool our knowledge and to the extent available, understanding, of the useage best practices we have gleaned.

We can start by posting our battery configurations, useage profiles, and perhaps most important, our charging parameters.

IMO, we have a lot to learn here.
Last edited by raysun on Tue Oct 27, 2020 10:41 am, edited 1 time in total.
raysun
Forum Emperor
Posts: 4624
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 48v)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: How are you charging your SimpliPhi battery?

Post by raysun »

My battery consists of six SimpliPhi 3.8-48 blocks for a total capacity of 450AH. My system is off grid with daily battery cycling. Typical daily consumption is 12kWH.

Charging parameters:
20201027_042921.jpg
System has dual FM80 charge controllers and 6.5kW of PV array.

Charging method chosen is Bulk to a target of 56.4V then terminate charge (Absorb voltage=56.4, Absorb Time=0.1).

Float parameters here deviate from the SimpliPhi recommendation of 54V. SimpliPhi implies float is not healthy for a LiFePo4 battery. In that typical float settings are intended to hold the battery at 100% SoC, I agree with their implication. IME, 54V Float does exactly what I don't want, by holding the battery at 100% SoC. Playing with Float, I found that 53V allows the battery to bleed off 1-2AH and holds a 99% SoC. The exact Float voltage chosen may vary depending on load, and the desired SoC target.

20201027_043011.jpg
System has dual FXR3048A inverters.
For inverter charging, I've chosen the same "Bulk to 56.4V then terminate" method as the PV charge controllers. I didn't bother setting the target voltage 0.4V lower, because I'm not concerned with setting charger priority (so far.) If both charging systems are employed, whichever is leading the dance at termination voltage seems to be fine.

Float is disabled. Equalize can't be disabled as such, but is not used.

20201027_043055.jpg
FNDC settings. Auto Charge Termination Control is being used (the 3 image limit precludes displaying the Mate settings here.)

Charged Voltage is set somewhat higher than usual (56V), but in line with setting it 0.4V lower than the lowest charger Absorb voltage.

Charged Return Amps = 9 is in line with the latest SimpliPhi integration guide recommending 1.5A per block. (The earlier guide recommended 2.0A). At the end of the charge cycle, the battery voltage rises rapidly, and the charge current falls even more rapidly. Within 1 minute of reaching 56.4V, the current declines to, and falls through, the 9A setting. Charge termination usually occurs 1-3 minutes into the "Absorb" phase.

I may reset the Charged Return Amps to 12A. I don't want the termination phase to last any longer than necessary.
Mike Curran
Forum Emperor
Posts: 2284
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: How are you charging your SimpliPhi battery?

Post by Mike Curran »

If both charging systems are employed, whichever is leading the dance at termination voltage seems to be fine.
I would agree for an off grid system where the only way the inverter would be charging a battery is if the generator is running, and in that case you really don't care what the charge source is - there's probably insufficient sun anyway.

But in a grid-tied system setting this differential is critical to preventing use of grid (buying energy) when PV is available.

Just wanted to make this point for any grid-tied folks who might get the wrong idea :smile:
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-04-19
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
raysun
Forum Emperor
Posts: 4624
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 48v)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: How are you charging your SimpliPhi battery?

Post by raysun »

Mike Curran wrote: Tue Oct 27, 2020 5:59 pm
If both charging systems are employed, whichever is leading the dance at termination voltage seems to be fine.
I would agree for an off grid system where the only way the inverter would be charging a battery is if the generator is running, and in that case you really don't care what the charge source is - there's probably insufficient sun anyway.

But in a grid-tied system setting this differential is critical to preventing use of grid (buying energy) when PV is available.

Just wanted to make this point for any grid-tied folks who might get the wrong idea :smile:
Yes, I have a strictly off-grid perspective. You grid-tied folks are welcome to chime in with your settings and considerations. 😀
Photon Kapture
Forum Member
Posts: 17
Joined: Tue Jan 14, 2020 4:54 pm
My RE system: 3.9 Kilowatt (13) Solar World sw300 Array.
Outback Skybox
(3) Simpliphi Lithium Iron Phosphate Batteries (2) 3.5 and (1) 3.8KWH
Location: Schroeder, Minnesota

Re: How are you charging your SimpliPhi battery?

Post by Photon Kapture »

Rayson,

Good thread. I’m running 3 Simpliphi 48volt batteries with a Skybox off-grid. Two 3.5 and one 3.8 kWh with another 3.8 on on the way. Since I have two of the earlier 3.5 kWh versions I’m using that charging profile which absorbs at 56volts for 10 min. My absorb end amps is set at 8. That came from outback’s recommendation of 2AH per 3.5 and 4AH per 3.8 Simpliphi. I’m not using float as Skybox passes solar thru to power loads once charging parameters are met.

I’m over a year in and happy with my battery setup, no issues with the Simpliphi.
Post Reply