featherlite
Solar Enthusiast
Can a fully programable PWM charge controller safely charge a Lifepo4 Battery?
I read an article that appears to say that PWM chargers produce too much ripple to safely charge Lifepo4 batteries.
The subject article appears at
https://nordkyndesign.com/charging-marine-lithium-battery-banks/
and says that
“The worst ripple voltage is produced by solar PWM charge controllers []. In the case of a solar PWM charge controller, the solar array is connected and disconnected from the battery at a fixed frequency. The open-circuit voltage of a solar array charging a battery in a 12VDC installation typically reaches up to about 22V (36-cell panel).
Once the battery can no longer accept enough current to keep the voltage down, every time the controller sends a pulse to the battery, the cell voltages are gradually driven towards 22 / 4 = 5.5V. If the pulse voltage reaches 4.2V, there is sufficient energy for the electrolyte decomposition reaction to take place and the cells get rapidly destroyed, even if the average battery voltage as measured by a multimeter appears acceptable.”
...
“If these [voltages] exceed about 4.20V/cell for the LiFePO4 chemistry, the electrolyte is broken down into gaseous products and pressure starts to build up into the cells.”
I am not asking about the relative advantages and disadvantages of PWM vs. MPPT charge controllers.
I am assuming the charge controller is fully programable so that the charge parameters can be set properly to charge a Lifepo4 battery.
FYI, I currently charge my 12v, 235Ah lead acid batteries with the Bogart SC 2030 charger, the Bogart TM 2030 monitor and (6) 100 Watt solar panels; for my converted cargo trailer.
I am thinking about upgrading to four or eight Eve prismatic cells, with BMS(s) and charging them with my Bogart system.
My apologies if this topic has been covered elsewhere on this forum; however, I searched the forum and found no relevant discussion about this particular issue
I would appreciate your thoughts.
Thank you!
I read an article that appears to say that PWM chargers produce too much ripple to safely charge Lifepo4 batteries.
The subject article appears at
https://nordkyndesign.com/charging-marine-lithium-battery-banks/
and says that
“The worst ripple voltage is produced by solar PWM charge controllers []. In the case of a solar PWM charge controller, the solar array is connected and disconnected from the battery at a fixed frequency. The open-circuit voltage of a solar array charging a battery in a 12VDC installation typically reaches up to about 22V (36-cell panel).
Once the battery can no longer accept enough current to keep the voltage down, every time the controller sends a pulse to the battery, the cell voltages are gradually driven towards 22 / 4 = 5.5V. If the pulse voltage reaches 4.2V, there is sufficient energy for the electrolyte decomposition reaction to take place and the cells get rapidly destroyed, even if the average battery voltage as measured by a multimeter appears acceptable.”
...
“If these [voltages] exceed about 4.20V/cell for the LiFePO4 chemistry, the electrolyte is broken down into gaseous products and pressure starts to build up into the cells.”
I am not asking about the relative advantages and disadvantages of PWM vs. MPPT charge controllers.
I am assuming the charge controller is fully programable so that the charge parameters can be set properly to charge a Lifepo4 battery.
FYI, I currently charge my 12v, 235Ah lead acid batteries with the Bogart SC 2030 charger, the Bogart TM 2030 monitor and (6) 100 Watt solar panels; for my converted cargo trailer.
I am thinking about upgrading to four or eight Eve prismatic cells, with BMS(s) and charging them with my Bogart system.
My apologies if this topic has been covered elsewhere on this forum; however, I searched the forum and found no relevant discussion about this particular issue
I would appreciate your thoughts.
Thank you!