That's a personal call. How long until you plan to fly again?
With my current schedule I fly almost every day (weather permitting) and I carefully track each battery and cycle through them so that no one battery gets used over and over. I put mine on a FULL charge every evening in preparation for the next day (4 batteries right now). If I don't fly in 5 days I have the packs programmed to start Auto Discharge (and I do not store them in my GoProfessional case because when they auto discharge they get pretty dang warm and HEAT is an ENEMY of Lipo) to storage levels.
I keep my "generic" LiPo packs at a storage charge of around 30% - 40% except I always keep one for my other quad at 100%. I cycle this through the (9) batteries I have and each one only stays at 100% for about 5 days before I put it into Storage levels and bring another one up to 100%. The reason for this is I always have a pack Flight Ready for SAR work here locally. While I'm traveling to and/or setting up at the SAR scene I charge additional packs up to 100%.
So no I don't think you need to worry about charging them up to the 50% mark but that's just my own personal opinion and you know what they say around opinions LOL