I'm working with my LiFePO4 lithium battery and trying to figure out how to set float charging. I know that LiFePO4 batteries don't necessarily need float charging, but my solar inverter doesn't allow me to turn off the float charging feature. I've already set the cutoff voltage to 21.6V and the bulk charging to 29.2V according to the manual, but I'm unsure what to set for float charging. Should I go with the nominal voltage of the battery, which is 25.6V?
2 Answers
When it comes to float charging, the best practice is to float them at their resting voltage, typically around 3.35V per cell. This voltage helps maintain the battery health without overcharging it. Adjust your settings accordingly!
For long-term health of your LiFePO4 cells, avoid charging them to 3.65V per cell too often. They’re typically considered full at around 3.4 to 3.5V per cell. Setting your float charging to about 3.4V per cell is a good idea, which translates to approximately 20.4V for a 6-cell pack. Just make sure to set your cutoff voltage to about 2.9V per cell since there's minimal energy below that level—keeping the cells in the 'flat' part of the charge curve is key!