lipo balancing
Usually Lipo's get out of balance if they are discharged close to the 6v cutoff. A balancer can only help, but balance while charging. Balancing a discharged battery before charging isn't that effective. Since a balancer costs $30 (electrifly,) it's a small price to pay to safeguard your lipo packs.
It's interesting that the same people who think $30 is a waste are buying $100 lipo packs, and $120+ chargers and think nothing of it.