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I am so excited for sodium ion. I already have like 5 projects in my head for useful application of it. Solar powered rain barrel water pump, replacements batteries for power tools, camping battery pack.
Sadly there aren't any charging chips out there for it yet, but one of my project ideas is to implement my own CC/CV from a greenpak chip.
What would be unique about a charging chip for sodium ion?
It doesn't charge to 4.2V per cell but instead to 4V or 4.05V.
Using the same charging chips as lithium that terminate so high would damage the cell.
Also the voltage drop is a lot more (4V->1.5V vs 4.2V–>3V), so lithium charging chips would detect it as a deeply discharged lithium cell and only charge at 40mA or so instead of fast charging or even a damaged, shorted out battery (so not charging at all and giving an error). So a problem on both ends.