Need help with setting up LiFePO4 battery parameters in a Solar Charge Controller.

Thread Starter

oridroo

Joined Feb 5, 2012
27
Hi,
I am trying to set up the parameters for a LiFePO4 battery bank for a solar charge controller. I have tried to search the internet for understanding the basics of LiFePO4 battery but couldn't find any source from where I can understand the logics to calculate the parameters. So please pardon my ignorance regarding the basics.
The charge controller I am using is: Wanderer by RENOGY.
The battery bank is consisted of 7 individual LiFePO4 battery cells (2500mAh, 3.7V) in parallel and three such paralleled cells in series.
So practically I'm getting ~10.219V out of the bank with individual cell's outputs are respectively 3.409V, 3.375V and 3.435V.

The parameters I'm trying to set up are:

High Volt Disconnect(V)
Charge Limit Voltage(V)
Equalize Charge Volt(V)
Boost Charge Volt(V)
Float Charge Volt(V)
Boost Charge Return Volt(V)
Over Disc Return Volt(V)
Low Voltage Alarm(V)
Over Discharge Volt(V)
Over Disc Relay Time(S)
Equalize Charge Time(Min)
Boost Charge Time(Min)
Equalize Charge Interval
Temperature Compensation(mv/C/2V)

These parameters are available in the App provided by the solar charge controller manufacturer from where the BMS can be configured.
Any help would be much appreciated.

Regards
 

Thread Starter

oridroo

Joined Feb 5, 2012
27
I suggest the sections on lithium batteries. The author lumps all of them into the same bucket. He gives a good description of the different chemistries and constructions. Of course, LiFePO4 have a lower voltage than Li-ion or Li-poly: https://www.powerstream.com/LLLF.htm
Thanks for the link. It provides some insights about LiFePO4 but I couldn't find anything specific regarding the parameters I enlisted in the OP like High Voltage Disconnect, Over Discharge Voltage etc.
The article says that the LiFePO4 cells can be safely overcharged upto 4.2V. So, if I want my cells to be charged not more than 4.15V, should I set the 'High Voltage Disconnect' as 12.45V?
Similarly, if I want my batteries not to get discharged below 3V, should I set the 'Over Discharge Voltage' as 9V?
 
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