Best charging behavior for LFP batteries

[giscus[bot]]

Best charging behavior for LFP batteries

I have been writing about the importance of LFP (LiFePO4) batteries for a while now, but I haven’t written about the best charging behavior for this battery chemistry yet.
It’s time to write a small, but important article about the subject, especially because I have seen some confusion on online forums.
First, let’s compare the nominal and maximum voltages of LFP with other popular battery chemistries.
LTO anode + LMO/NCM cathode

https://pushevs.com/2022/04/21/best-charging-behavior-for-lfp-batteries/

[JFRosado]

A question remains:

If LFP have such a flat curve, then there's no difference in voltage (or almost none) being it at 100% or at 70%. Or let's say, being it at 90% or 70%...

So, are we entering in a contradiction?

[LITUATUI]

Good question.

The other thing that damages battery cells is high temperatures, since charging isn’t 100 % efficient, the more you charge the battery the more you heat it. Especially if you’re using fast chargers and charging at high C-rates…

But I agree, the 70 % charging limit is just a general recommendation for lithium-ion batteries, you can definitely charge LiFePO4 battery cells higher than that with little damage done.

Check these charts:

https://www.bravabatteries.com/lifepo4-battery-discharge-and-charge-curve/

https://gwl-power.tumblr.com/post/140925159571/the-cycle-life-of-winston-batttery-cells-versus

[JFRosado]

To be more precise, the limit in NMC or NCA cells is the 4.0V.

For LFP, i have no idea...

[LITUATUI]

For LFP the charge limit is usually 3,55~3,65 V.