Yes, it's normal and yes, it's the balancing. And no, you don't need to discharge before charging.

In fact, LiPos should never be stored fully charged or fully discharged, but in a certain voltage range, called "storage voltage" - that's what your battery was at (they are sold like that), so of course it needed less than 4800 to get to a full charge, since it wasn't really empty. In fact you must never run a LiPo below 3.0V per cell at all, some say even 3.2V with today's HV cells - otherwise you can easily damage or destroy you battery. If you want to treat your batteries a little better, set your personal limit even higher (~3.5V). Most modern ESCs have a setting at which they will either become noticeably slower or immediately stop running at a certain voltage. I always set mine relatively high, so I never end up with less than 3.5 or 3.6V per cell. Unlike NiCd, LiPos also have no memory effect, so you basically never need to discharge them below storage voltage at all. (What some people do - not saying you should! - is a full cycle, they discharge and immediately charge the battery again, both with very high Amps (20-40, possibly up to 70), which will heat up the battery internally, which lowers it's internal resistance (IR) and supposedly brings a tiny bit more performance for stock class racing - but at the cost of battery life, and some people say safety as well, so I don't recommend you do that.)

But all this is pretty much basic LiPos knowledge. If you didn't know any of it until now, you should better start reading up about LiPo care quickly, or watch some video tutorials, because without basic knowledge, you can and likely will damage your batteries - and what damaged LiPos can do... well, you've already heard. They're only safe if treated correctly!