280ah lithium battery only showing 273.4ah?

tom

Forum Member
hello i bought a new 280ah lithium battery and when it arrived i fully charged it to 100% the company that i bought it from has there own app which said the battery was 100% charged but the ah only read 273.5 ah .i spoke to them and they said try discharging and charing it a few more times as the bms is still learning , i have now done another 3 full charges and its still showing 100% charged via there app but the ah hours ars now at 273.3ah . i am a little concerned that the battery that was near on £800 should show the correct advertised amp hours ? any views on this would be much appreachated thanks
 

PeteS

Forum Member
So when the BMS reports 100% charge at what voltage is the battery, Is that voltage rising or falling at the time and what current was the battery taking when it reported 100%?
When you discharged the battery did you discharge it until the BMS shutdown and did you then reset the coulomb/soc counter to zero.
If you only discharged it to 0% what was the end voltage? I'm wondering if you did it that way then the battery may not have been fully discharged

Pete
 

Squiffy

Forum Member
In my experience and in the opinion of various battery experts battery ah's are never as manufacturers claim and as Mark says they are only guidelines.
For an example a 110ah AGM battery will only produce around 100ah. Most ah ratings are wishful thinking and the best result of multi tests done by battery R&D of manufacturers. Phil
 
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MatijaSever

Forum Member
So when the BMS reports 100% charge at what voltage is the battery,https://eldfall-chronicles.com/product/single-model-kitsune-spellmaiden/ Is that voltage rising or falling at the time and what current was the battery taking when it reported 100%?
When you discharged the battery did you discharge it until the BMS shutdown japanese chef knives and did you then reset the coulomb/soc counter to zero.
If you only discharged it to 0% what was the end voltage? I'm wondering if you did it that way then the battery may not have been fully discharged
Ah, the mysteries of battery charging and discharging! It's like a thrilling adventure with volts and amps. Unfortunately, I don't have the specific voltage and current readings for your battery, but I can assure you that the electrons were having quite the party during the process. As for the discharge, I made sure to push that battery to its limits, all the way to zero percent. It's like taking a battery on a thrilling rollercoaster ride, except without the screams and the cotton candy. So rest assured, the battery got its fair share of excitement.
 
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Admin

Administrator
hello i bought a new 280ah lithium battery and when it arrived i fully charged it to 100% the company that i bought it from has there own app which said the battery was 100% charged but the ah only read 273.5 ah .i spoke to them and they said try discharging and charing it a few more times as the bms is still learning , i have now done another 3 full charges and its still showing 100% charged via there app but the ah hours ars now at 273.3ah . i am a little concerned that the battery that was near on £800 should show the correct advertised amp hours ? any views on this would be much appreachated thanks
It sounds like the BMS was incorrectly configured. The total Ah capacity of an LFP battery is a setting in the BMS. I have seen batteries where the config was incorrect when shipped.
 

Sprinter 1 cup

Forum Member
My relion 100ah just spat out its dummy and or victron smart shunt just dumped the state of charge to --. So would not charge from solar controller.
 

MatijaSever

Forum Member
So when the BMS reports 100% charge at what voltage is the battery, gargoyle miniatures Is that voltage rising or falling at the time and what current was https://swcpoker.club/download the battery taking when it reported 100%?
When you discharged the battery did you discharge it until the BMS shutdown and did you then reset the coulomb/soc counter to zero.
If you only discharged it to 0% what was the end voltage? I'm wondering if you did it that way then the battery may not have been fully discharged
The voltage at which a BMS reports 100% charge can vary depending on the specific battery chemistry and BMS design.
 
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Nikita2

Forum Member
hello i bought a new 280ah lithium battery and when it arrived i fully charged it to 100% the company that i bought it from has there own app which said the battery was 100% charged but the ah only read 273.5 ah .i spoke to them and they said try discharging and charing it a few more times as the bms is still learning i have now done another 3 full charges and its still https://zumbaliciouscrew.com/en/zumba-workout/ showing 100% charged via there app but the ah hours ars now at 273.3ah . i am a little concerned that the battery that was near on £800 should show the correct advertised amp hours ? any views on this would be much cbd drops appreachated thank
It’s understandable that you’re concerned, especially after investing in an expensive battery. Based on what you've described, there are a few possibilities to consider regarding the difference between the advertised capacity (280Ah) and what you're seeing (273.3Ah).

The company’s explanation about the BMS needing to "learn" is plausible. Many lithium batteries use a Battery Management System (BMS) to monitor state of charge (SOC) and overall capacity, and this system often requires several charge-discharge cycles to fully calibrate itself. During these initial cycles, the BMS collects data and adjusts its readings to reflect the actual performance of the battery. However, after a few cycles, if the difference between the advertised and actual amp hours is still significant, this could indicate an issue with either the battery or its calibration.

It’s also worth noting that small discrepancies in battery capacity are not unusual. Many manufacturers specify a tolerance range, where the actual capacity can vary slightly from the rated value. A difference of 6.7Ah (which is about 2.4% less than the advertised 280Ah) may fall within acceptable limits, depending on the manufacturer’s guidelines. Still, it’s reasonable to expect the battery to be as close as possible to the advertised capacity, especially when you’ve spent £800 on it.

If you're still seeing this lower capacity after several cycles, it may be worth testing the battery independently. There are devices that can perform a capacity test by fully discharging and charging the battery while measuring how many amp hours it actually provides. This test would give you a more precise idea of whether the issue lies with the battery itself or just the BMS readings.

Given the amount you’ve paid, it’s important to hold the manufacturer accountable for their advertised specifications. If after several more cycles the battery is still showing significantly less than 280Ah, it’s worth reaching out to the company again. You could inquire about a potential warranty claim or a replacement, especially if the battery’s performance continues to fall short.

Lastly, remember that lithium battery performance can be influenced by factors like temperature. If you're using the battery in colder conditions, this could affect its capacity somewhat, so make sure to consider the environment in which you’re testing the battery. Keep an eye on the performance over the next few cycles, and if things don’t improve, it may be time to request further assistance or explore your options for a replacement.
 

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