LifePO4 GBS Amp Hour Testing 2.5v to 3.6v per cell

[Sunking]

I am not talking about Specific Power, I am talking about voltage sag and charge loss characterised by the peukert law.

Voltage Sag is Specific Power period. You have no clue what you are talking about. Peukert Law has nothing to do with Specific Power or Voltage Sag. You are really making a fool of yourself. Here is your education from MIT

Specific Power (W/kg) – The maximum available power per unit mass. Specific power is a characteristic of the battery chemistry and packaging. It determines the battery weight required to achieve a given performance target.

Peukert Law expresses approximately the change in capacity of rechargeable batteries at different rates of discharge.

[karrak]

The discussion has been about voltage sag with time, I will amend the original post to make it clearer

[Sunking]

I am not talking about the cost of the battery divided by its rated capacity, I am talking about the cost per kWh cycled through the battery over its lifetime.

So am I, Pb is much more cost effective. I have proved it many times, get over it one trick pony.

[Sunking]

Good luck trying to calculate the Ri from the discharge curves. It is a constantly moving target especially with lead acid batteries.

It is easy peasy, a fith grader can do it. If you understood math and Ohm's Law you would know better. I can look at any discharge graph and tell you the Ri within 5 seconds at any point. It looks exactly like the Charge Discharge cures.

Even Jesse aka Creathis knows how, I taught him how to do it, He made a video how to do it. Watch it and learn from him who knows more than you do now. because he listened. I learned how 40 years ago from the battery manufactures. That is why they publish Charge and Discharge curves. Very simple find Delta Voltage and Current which screams out at you when you look at the graphs. If you really knew anything about batteries, you would know that. Jesse is a beginner and he knows it. How many years did it take you to get so ignorant?

[createthis]

No heat is not going to be an issue for you. You will not be able to pull 200 amps from your batteries for any meaningful amount of time for them to get hot enough to worry about. Using 1% rule on battery voltage sag, your batteries are only good for 20 amps (C/5) or 1/10th what you want.

Good luck, time for me to go play

It pulls about 145 amps just fine:

Jump to 7:36 for the 145 amp draw. Tried to jump there from the link, but it wouldn't let me.

I'm really not sure where you got that 20 amp figure from, unless you're assuming a certain runtime.

I did decide to derate the whole system with a 150 amp DC breaker.

[Sunking]

I'm really not sure where you got that 20 amp figure from, unless you're assuming a certain runtime.

I know you do not understand and that is the problem. You don't understand and then make videos about how things work. For one you do not understand why your battery voltage dropped from 13.6 to 12.4, and why that is a huge problem.

[createthis]

I know you do not understand and that is the problem. You don't understand and then make videos about how things work. For one you do not understand why your battery voltage dropped from 13.6 to 12.4, and why that is a huge problem.

More assumptions. I never said I didn't understand why the voltage dropped.

[Sunking]

More assumptions. I never said I didn't understand why the voltage dropped.

No assumptions made, you do not understand or else you would have understood the 20 amp current comment. When a person uses a battery operated device, he/she expects it to be safe, and all the battery capacity to be usable.Pulling 145 amps from a 100 AH battery will not allow you to use all the battery capacity and is quite dangerous. Sure you can make it work for a few minutes, but beyond that your Inverter is going to shut down from under voltage way before the battery capacity is depleted and running the risk of a fire.

How would you like it if you bought an EV and the manufacture claimed you get 100 mile range. You take it, go 50 miles and the EV comes to a stop from a dead battery. You return the vehicle, and the dealer ask how fast were you driving and you answer 60 mph, the dealer laughs and says you have to go 20 mph to get 100 mile range.

[createthis]

No assumptions made, you do not understand or else you would have understood the 20 amp current comment. When a person uses a battery operated device, he/she expects it to be safe, and all the battery capacity to be usable.Pulling 145 amps from a 100 AH battery will not allow you to use all the battery capacity and is quite dangerous. Sure you can make it work for a few minutes, but beyond that your Inverter is going to shut down from under voltage way before the battery capacity is depleted and running the risk of a fire.

Where does this risk of fire come from?

[Sunking]

Where does this risk of fire come from?

I rest my case. Keep repeating your test and you will find out.

[createthis]

I rest my case. Keep repeating your test and you will find out.

Very clever. Teaching us all a lesson with that one.

[Sunking]

Very clever. Teaching us all a lesson with that one.

Jesse I have given up on you. You do not listen. Like your last thread you posted about hybrid Inverters, half a dozen different engineers and techinicans tried to help you, but all you want to do is fight the facts you cannot use a MSW Inverter with a hybrid. The Commercial AC port requires a 2-way utility connection, and generator with a real generator.

You have been told, now go learn the hard way. You are like Karrak, dangerous, You only know enough to be dangerous, and if you are not careful, will get yourself banned from the forum like Karrak did temporarily for unsafe practices.

[createthis]

Jesse I have given up on you. You do not listen. Like your last thread you posted about hybrid Inverters, half a dozen different engineers and techinicans tried to help you, but all you want to do is fight the facts you cannot use a MSW Inverter with a hybrid. The Commercial AC port requires a 2-way utility connection, and generator with a real generator.

You have been told, now go learn the hard way. You are like Karrak, dangerous, You only know enough to be dangerous, and if you are not careful, will get yourself banned from the forum like Karrak did temporarily for unsafe practices.

I'm waiting to for you to tell me where the perceived fire risk is in my current system. I can't listen if you don't speak. I doubt I'll get banned for asking a question.

[jflorey2]

Where does this risk of fire come from?

I²R heating.

[createthis]

Regarding I2R heating:

No heat is not going to be an issue for you. You will not be able to pull 200 amps from your batteries for any meaningful amount of time for them to get hot enough to worry about. Using 1% rule on battery voltage sag, your batteries are only good for 20 amps (C/5) or 1/10th what you want.

Good luck, time for me to go play

I love getting told I don't listen when I can quote contradictory material, btw. Keep it comin.

[Sunking]

Regarding I2R heating:



I love getting told I don't listen when I can quote contradictory material, btw. Keep it comin.

Nothing is contradictory, you are not understanding the information being given. That is why people are getting short with you. Over heating the batteries is not the issue. Those batteries are rated at 2C contentious. All that means with a lithium battery is it is thermally capable of being discharged at 2C. But that has nothing to do what I am talking about. You are off on a tangent.

So try this experiment. Repeat what you did, but at least collect some data with meaning.

1. Before you start measure the Open Circuit Voltage of the batteries directly on the battery term post.
2. Put your 1.8 KW load like you did in the video and let it run while you take some measurements.
3. Measure the voltage directly on the Battery Term Post again.
4. Measure the voltage directly and physically on the Inverter Input Term Post with the load cooking away.

Now tell me what you think is going on, and why you think it is safe and practical to run a 2000 watt Inverter on a 12 volt 100 AH battery.