LiFePO4 Voltage Chart?

[buyone]

That makes no sense. Couloumbic charge efficiency of LiFePO is about 100%. If you are charging with a constant current from 0% to 100% the last 20% (from 80% to 100%) takes exactly 20% of the time.

If you are trying to define your point of 80% charge from your table of voltages above, you are just fooling yourself. If you are not in the top or bottom "knees" of the curve, you need to have the cell resting for many hours before you can get any idea of charge state from voltage. Even then, it's extremely blunt.

Your theory is not the same as RW behavior.

 

[buyone]

You are fooling yourself. If you want to know the state of charge of a cell without letting it rest for a long time, you need to do Coulomb counting. Trying to gain information from cell voltage while charging and comparing that to a table of resting cell voltages is nonsensical. I'll leave you to your illusions and remain in the real world...

Coulomb Counting is the only way to know SoC. My measurements show no change (0mV) in cell V terminal while charging at 5A, for a charge delta of 50 Ah (17% capacity).

 

[Mikenkarie]

Sajjjen, Real world?? Real world does not consist of resting, your charger will never get that luxury when choosing when to stop charging or start charging when your load and discharge is Always at least 1500 watts every second of every day for whole house AC Couple, except for the random vacation in the bahamas you will NEVER have any kind of "resting" period, so your little idea in a vacuum "coulomb counting" is not possible in a REAL world application and so we come here to try and figure out our own personal comfort zone and choosen charging/discharging operating mode, Especially when you, like 99.999% on here have mismatched Branded, batteries to Inverter, to charger that is either solar or grid charger or all in one and then either a different brand BMS, shunt, battery combo. No one has the same everything.

Your ground hog day does not provide resting of any kind, it consists of pushing a charge uphill as fast possible with your random solar output or grid charge setting one day to the next holding a bulk charge Voltage setting on that uphill battle, (2 hours in, clouds form, rain starts, charge stops from solar, and your batteries start the plunge, 2 hours later lightning strikes somewhere and the grid drops for about 10 minutes), if you choose Grid charge you didnt skip a beat depending on your size of inverter (microwave, oven, hot water heater, kids, wife, dryer, and Air conditioner all randomly doing what they want to push you over 10,000 watts and now you have no grid left to charge with, and you hope to get available amps back to work/charging after the random outage, otherwise maybe 2 days later the sun finally comes back out and your solar charger helps you go back to your uphill battle, then once again you hold the line and hope and pray you can reach the top end voltage (at this point youve already learned the hard way, you never set a charger to forcefully hit 100% battery or you will damage or burnout or shorten the life of your battery or BMS guaranteed), so let's say the system hits your Top setting, your specific charger's or your custom top % / voltage mark. Charging stops and you hope you got some top end balancing during the last 2-5%, and then imediately your batteries begin the freefall plunge again back to the bottum because the discharge / load from your house never stops and your "charge operation" isn't coming back on until you hit the bottum all over again.

 

[ionlyski]

I am confused about contradictions LiTime posts in their information and manuals. You read some of their specs and then a paragraph later they self contradict. Such as these two statements almost right next to each other. What gives?

LiFePO4 batteries can be discharged up to 100% of their capacity without significantly reducing their lifespan. They support deep discharge without damage.
And this:
Discharging below the recommended voltage level can cause permanent damage to the battery and reduce its lifespan. It’s important to avoid deep discharges to maintain optimal performance.

 

[MisterSandals]

LiFePO4 batteries can be discharged up to 100% of their capacity

This is pretty close to 2.5Vpc as there is virtually no capacity below this voltage.

Discharging below the recommended voltage level can cause permanent damage

The recommended value should be 2.5V.

I do not see a contradiction though it could be worded better or even specify a voltage rather than vaguely saying "level".