like the normal lithium batteries there are multiple chemistries does lifepo4 have multiple chemistry variants?
while watching a video https://www.youtube.com/watch?v=8-Lwy42mbsw
Bluetti EB3A Portable UPS Powerstation Teardown and Demo
i noticed that it uses supposedly 7s2p of lifepo4
the termination voltage of a 7s lifepo4 based on 3.65 volt per cell should be 25.55 the video measured 27.25 volts that would be 3.89 almost 3.9 volts.
that does not seem right so.
1. lifepo4 does not have just 1 formula there are multiple formulas making it possible to manufacture lifepo4 cells without violating a123 and the patent of the original mit version.
2. fresh new cells will come off the charger slightly higher but as they break in the voltage will go down to 3.65 while the capacity comes up.
3. the unit is using standard lead acid based ups board or charger with lifepo slapped on it so the floating voltage will push the cells into the danger zone.
4. today's lifepo4 is not your father's lifepo4 and can tolerate slightly more similar to LIHV.
5. back when lifepo4 was first developed long term overcharging effects was not known and now they are finding out it is safe to charge at 3.89 volts.
6. they are not lifepo4 but normal lithium 4.2 volt maybe NMC or something witch makes it more stable so it wont catch fire.
hopefully someone knows why the higher voltage.
while watching a video https://www.youtube.com/watch?v=8-Lwy42mbsw
Bluetti EB3A Portable UPS Powerstation Teardown and Demo
i noticed that it uses supposedly 7s2p of lifepo4
the termination voltage of a 7s lifepo4 based on 3.65 volt per cell should be 25.55 the video measured 27.25 volts that would be 3.89 almost 3.9 volts.
that does not seem right so.
1. lifepo4 does not have just 1 formula there are multiple formulas making it possible to manufacture lifepo4 cells without violating a123 and the patent of the original mit version.
2. fresh new cells will come off the charger slightly higher but as they break in the voltage will go down to 3.65 while the capacity comes up.
3. the unit is using standard lead acid based ups board or charger with lifepo slapped on it so the floating voltage will push the cells into the danger zone.
4. today's lifepo4 is not your father's lifepo4 and can tolerate slightly more similar to LIHV.
5. back when lifepo4 was first developed long term overcharging effects was not known and now they are finding out it is safe to charge at 3.89 volts.
6. they are not lifepo4 but normal lithium 4.2 volt maybe NMC or something witch makes it more stable so it wont catch fire.
hopefully someone knows why the higher voltage.