Looks like the article on Jason's website answered my question. I need a new battery charger.
I think JASONHC is correct ...
Charging LiFePO4 is a two step process … FIRST step uses constant current (CC) to reach about 60% State of Charge (SOC); And then STEP 2 kicks in until the charge voltage reaches 3.65V per cell. Turning from constant current (CC) to constant voltage (CV) means that the charge current is limited by what the battery will accept at that voltage, so the charging current tapers down asymptotically.
If you had to time the process – STEP ONE (60% SOC) needs about one hour and the STEP 2 (40% SOC) needs another two hours .. I have seen it that way ever since I started working with LiFePO4
By looking at the SOC table provided from the manufacturer.
All tables are for reference.As in a voltage vs SoC table? Such a table only makes sense if the cells are well rested. During charge, it means nothing.
Another purpose of buying lithium batteries is to get long life, right?20-80% range means you miss 40% of your battery capacity. That's ok, but the purpose of getting these battery was you do not need to half discharge them only like lead. I think a 15-95% range would be more efficient for your dollars.
Another purpose of buying lithium batteries is to get long life, right?
Anyway, is percentage of battery used determined by your settings in the BMS? Settings of discharge and overcharge voltage? I am new, so forgive me if this is a dumb question.
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...
Exactly 3.73 hours, or 3 hrs and 44 minutes. Assuming your charger is connected to the battery with very little voltage loss, i.e. heavy gauge and very short cables. At these parameters the entire charge will be in CC mode, so the math is very simple - (280AH * 60%) / 45AHow long should it take me to charge a 280ah 12v battery from 20% - 80% with a 45amp smart charger? The charger tops out at 13.6 volts.
I too have used batteries and I just charge to 13.8 4s pack. I just need to use custom settings on chargers. Too many chargers are fixed at 14.4 and don't allow custom settings.
SOC V Cell My Limits My Limits My Limits My Limits 48V setup Self imposed Self imposed Self imposed Self imposed 12V Setup 24V Setup 48V Setup 100.00% 58.40 3.65 3.294 13.2 26.4 52.7 99.50% 55.20 3.45 99.00% 54.00 3.38 90.00% 53.60 3.35 3.277 13.1 26.2 52.4 80.00% 53.20 3.33 3.260 13.0 26.1 52.2 70.00% 52.80 3.30 3.242 13.0 25.9 51.9 60.00% 52.40 3.28 3.225 12.9 25.8 51.6 50.00% 52.20 3.26 3.208 12.8 25.7 51.3 40.00% 52.00 3.25 3.191 12.8 25.5 51.1 30.00% 51.60 3.23 3.173 12.7 25.4 50.8 20.00% 51.20 3.20 3.156 12.6 25.2 50.5 14.00% 50.40 3.15 9.50% 48.00 3.00 3.156 12.6 25.2 50.5 5.00% 44.80 2.80 0.50% 40.60 2.54 0.00% 40.00 2.50 2.950 11.8 23.6 47.2
View attachment 5359
My self imposed limits are based on what the cells return to after a bulk charge. For the first month, I was bulk charging to 3.55V per cell, they always returned to 3.295V on their own, so why try to force them. Let them be happy at 3.295 and "call it 100%".
These are for USED cells.
New cells are just that. Battleborn expressly states to use them 100 to 0, but charging them to 90 will let the cells last far far longer. It takes 3 times more time to go from 80% to 100% as it does from 0% to 80%. But it takes about 30 minutes to go from 100% to 80%, and 24 hours to go from 80% to 0%.
I set my 0% SOC at the top of the slope down to zero at about 15% SOC actual, I simply don't use that very low end so I can avoid further degradation. LiFePO4 cannot be fixed once degraded, it's a one-way process.
Hi guys, I was looking through the mobile-solarpower.com website, and on this page I found a battery voltage chart for LiFePO4 batteries.
But I noticed it wasn't showing the exact voltage ranges that my battery data sheet does.
My data sheet shows 100% charge at 14.6V and 0% charge at 10.0V.
Battery Model 100Ah 3.2V Nominal Voltage 3.2V Standard Charging Current 0.5C (50A) Standard Discharging Current 0.5C (50A) Fast Charging 1C (100A) Charging End Voltage 3.65V (14.6V) Discharge End Voltage 2.5V (10.0V) Charge Temperature Range 0 - 55°C Discharge Temperature Range -20 - 55°C Max Cont. Discharge Current 1C (100A) Max Burst Discharge Current 3C (60sec) (300A) Impedance <045mΩ Screw Terminal M6 Weight 2.2Kg (8.8Kg)
I thought that maybe I could make my own voltage chart more suited to my battery's specifications, shown below.
Capacity % Pack Voltage Cell Voltage 100% 14.60 3.65 99% 14.45 3.61 95% 13.87 3.46 90% 13.30 3.32 80% 13.25 3.31 70% 13.20 3.30 60% 13.17 3.29 50% 13.13 3.28 40% 13.10 3.27 30% 13.00 3.25 20% 12.90 3.22 17% 12.80 3.20 14% 12.50 3.12 9% 12.00 3.00 0% 10.00 2.50
I was wondering if someone could cast their eye over it and let me know if anything needs to be changed. I'm a beginner at this so would like to learn how to be accurate when making the voltage chart.
Thanks.
I see lots of batteries on this site:Just simply observing and waiting for the charge to be higher.
Yes, I get it the resistance getting much much higher as the cause. That's why they are so much less expensive as used, and frankly why they are not still being used where they were installed.
Are there any other site resources to go to? Or is LG Chem only one?
Would you have a recommendation for the type of sensor I could purchase in regards to a shutlnt sensor for checking capacityWith such a huge change (70-30%) over just a 0.2V range you're really not getting a very good idea of the actual SOC by using voltage. IMHO using a shunt/hall sensor is really the best way to tell how much power is left in your pack.
Would you have a recommendation for the type of sensor I could purchase in regards to a shutlnt sensor for checking capacity