DC HOUSE battery SOC chart

[lilrez]

Just recieved these 2 batterys from amazon. Great deal .
The literature shows the SOC chart with a short band in comparison to others including ecoworthy literature and does not align with the operational range voltage.
Looking for you thoughts?

 

[grizzzman]

Just recieved these 2 batterys from amazon. Great deal .
The literature shows the SOC chart with a short band in comparison to others including ecoworthy literature and does not align with the operation ration voltage.
Looking for you thoughts?

I have three. All three tested just under 105 AH. I would not take much stock in voltage as a gauge of SOC. I use a Victron Smart Shunt and found it to be very accurate.

 

[Steve_S]

Doing the numbers & something is NOT RIGHT !
They state that these are LFP cells and LFP like all other chemistries has 2 Voltage Curves.
The "Allowable" range (2.500-3.650 volts per cell) which is the safe voltage range where no harm, damage or deterioration occurs.
The "Working" Range (3.000-3.400) which is the very flat voltage curve that is supposed to deliver the rated Amp Hours of the cells. This is in fact the Voltage Range that companies test & validate the cell capacities to.

Assuming that the cells used are standard LFP the profile below will provide a comfortable moderate charging profile which will maximize your capacity with the least stress.

NOTES: You have 12V Batteries but do not mention if you are using then as 12V/24V/48V.
IF Paralleling the packs, ensure the battery cables are the same length and connected to a proper busbar.
FUSE Each Battery Pack !!! a 100-125A Fuse is sufficient for each one.
If using them in Series to make 24V or 48V then you must be careful on the wiring setup to ensure balanced charging & discharging.
Wire Lengths ARE important, even 1/2" can affect the batteries.
KEEP the battery cables (bat to busbar, busbar to inverter) TOGETHER ! DC wiring creates magnetic fields & electrical noise, keep them close together to manage that.

CHARGING PROFILE:
All equipment MUST BE Voltage Corrected & Calibrated (VERY IMPORTANT)
Divide Values X2 for 12V. Multiply X2 for 48V.
NB: VPC = Volts Per Cell)
Bulk / Absorb: 27.6V (Absorb for 45 minutes (3.45vpc) (some call this boost)
Equalize: OFF
Float 27.5V (3.437vpc)
MIn Volts: 21.2V (2.650vpc)
Max Volts: 28.6V (3.575vpc)
Rebulk Voltage: 25.6 (3.200vpc)
End Amps/TailCurrent: *1 (Triggers change from Absorb to Float)
(*1): End Amps is calculated: (100AH X 0.05 = 5A or 280AH X 0.05 = 14A.
EndAmps = TailCurrent
Coulumbic Efficiency / Battery Status Meter Efficiency for LFP = 99%.
This gets the bank charged to full with high amps (Constant Current Constant Voltage) and then float (Constant Voltage, Variable Current) tops off so the cells are at 3.437Vpc. I
! Do Not forget to adjust for Voltage Offsets between Actual Voltage @ Battery Terminal & at Solar Controller.

BMS With Active Balancing should be set to start Active Balancing at 3.420V or possibly lower to 3.410 so that the cells can balance out at the top and not affect the charging process.

Very Special NOTE: Floating & Saturating to 3.437vpc, accounts for the Voltage Settling post Charge of any kind which actually brings the cells to just below 3.400Vpc.

 

[lilrez]

I have three. All three tested just under 105 AH. I would not take much stock in voltage as a gauge of SOC. I use a Victron Smart Shunt and found it to be very accurate.

Nice thank you !

 

[lilrez]

13.1v when recieved
On charge all day
Noco lithium 5 amp charger is only showing 13.7 and 13.9 at full charge . ?

 

[grizzzman]

13.1v when recieved
On charge all day
Noco lithium 5 amp charger is only showing 13.7 and 13.9 at full charge . ?

You brought into the knee so yes. How many hours did you charge it?

 

[lilrez]

About 9 hrs ..the charger was showing green. Ill plug it back in

 

[grizzzman]

You have put in 45 AH under the assumption of the charger output 5 amps the whole time, and assuming it was shipped at 30% (30 AH) and you come up with a "guess" of 75 AH

 

[lilrez]

You have put in 45 AH under the assumption of the charger output 5 amps the whole time, and assuming it was shipped at 30% (30 AH) and you come up with a "guess" of 75 AH

Ok
So what was the voltage of each of your three batteries when " full"

 

[grizzzman]

Ok
So what was the voltage of each of your three batteries when " full"

The first charge was at 14.6 at 20 Amps as it was a test tell the BMS disconnected. Then discharged tell BMS disconnected. This also allowed balance time and confidence that the BMS does its job. The battery does not have cold temp cut off but I let the MPPT handles that. The MPPT is set at 14.1 volts 5 min. Absorb and tail current then float is set to 13.48 volts.

 

[lilrez]

Good to know. Thank you

 

[lilrez]

Any reason why i cant pair the 2 100ah batteries i have from DC house with another 2 from ecoworthy? Assuming same same ??

 

[grizzzman]

Any reason why i cant pair the 2 100ah batteries i have from DC house with another 2 from ecoworthy? Assuming same same ??

I would have no issue with it.

 

[lilrez]

Put the DC house batteries to the test yesterday. Worked great!

 

[MisterSandals]

pair the 2 100ah batteries i have from DC house with another 2 from ecoworthy?

Just be sure to wire them in a balanced manner so that they all receive equal charge and discharge current.