Battery discharge even at no load

FrankNice1

Am using a
12/230ah vitra battery,
12/24v sachet inverter 
12/24v 40ah powerMr charge controller 
The charge controller enabled me to do equalization charging of up to 3 hours and absorption mode of up to 2 hours but yet without load after getting a 13 volt around 6pm it's discharged down to 12.6 volt.
The battery is less than a year old and from calculation it can't power a load of 100w for 6hours 

FrankNice1

The battery, cc, and inverter