280ah lithium battery only showing 273.4ah?

[tom]

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

 

[SquirrellCook]

BMS's take guess, it's not like someone physically counts the coulombs.
Sometimes people expect too much.

Mark

 

[tom]

BMS's take guess, it's not like someone physically counts the coulombs.
Sometimes people expect too much.

Mark

Advertised as 280ah so should be 280ah

 

[PeteS]

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]

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

 

[tom]

thanks for everyones reply the seller has agreed to replace the battery for me

 

[Sprinter 1 cup]

thanks for everyones reply the seller has agreed to replace the battery for me

So thats great and a good price with bms. Whats the company name.

 

[Pudsey Bear]

So it was down the capacity of a smartphone.

 

[Admin]

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.

 

[st3v3]

. I have seen batteries where the config was incorrect when shipped.

Have you?? Where was that???

 

[Admin]

Have you?? Where was that???

LOL

 

[Sprinter 1 cup]

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.