A new battery has storage chemicals and can take around 15 charges to become fully stable/tuned, so I us a 10-50 lipo system meaning fully charge then use down to 50% only and then charge and back down to 50% until this has been done over 10 times... but now your battery is around 19 charges should be ok as long as it was not used hard in the first 10 charges..
once past 10 charges it is then best to calibrate it by flying until it will fly no more and try get the battery down to 7% or less, I get mine down to less than 5% using a power drain.
Ive even had a battery down to 0% once - at this point i will explain that the go app is set 5% lower than what the battery is, when the go app shows the battery at 5% it is actually 10% or more so at 0% on the app it is 5% or more.. so when i say drain down to 7% i mean 7% on the app.
then after the battery has cooled, fully charge to 100%.. this is calibrating it, resetting its memory and so it can make all cells even ect.
If the battery has been flown down to 50% or less but then left a day or more and used again without charging the cells are not as compact so it might think it has 50% left but only have enough flow as 30% making a power fail. so neber fly with a battery that is only 50% to start with as it can even damage it.
Lipos if treated well and with respect can last many years but one that has not can only last a few charges, sorry if ive waffled or not explained the best that i could.
use it down to as low as you can to 5% and recharge then check the cells is what to do to see if it stablises