problem with sony vaio T battery when reinserting

i've observed this for a while now. i use the laptop on AC all the time, i rarely use the battery so i decided to remove it since it's not being used (yes, i know sony has battery care function but still i noticed battery wear on my laptop increases pretty quickly, dunno why maybe bec of it being plugged in to ac all the time)

i removed it several times and i always encounter this problem: the battery led flashes rapidly. it does not recognize the battery and won't charge? this is the original battery that came with the computer. i have tried several tips i found online but still no single method works. still won't charge and led blinks.

i have to insert, remove, reinsert, plug in ac, remove ac, turn on with battery, turn off then on again without battery, etc. so basically i have to do this method repeatedly and see whichever works. there was this instance though that i inserted the battery then it's blinking of course, i removed ac and it shut off, when i turn it back on, it recognizes the battery. but the other time i did it, it doesn't work anymore.

sometimes i'd be lucky enough to not go through this things but most of the time, i really have to do it randomly see whichever works. it's very inconvenient. i have HP laptop before and removing and reinserting battery never seem to be a problem.

i hope you can help. i already called sony tech support and they said that the battery should be working as soon as it's reinserted but how come it does this?