Just found this on another site
Balancing, and more specifically the NEED to balance is a hotly contested subject right now. In my experience and opinion, if a pack (especially just a 2 or 3 cell car pack) actually requires balancing during any time during it's lifespan, you'd do well to look into another brand. That's a harsh viewpoint, and may not be shared by many openly, but it's my honest opinion from working with many many brands for many many years.
Basically, you can view balancing a lipo pack like a continuing process of matching NiMH cells. NiMH cells are manufactured by the billions and due to this large scale of production economy, each and every one is slightly different. Just about everyone is familiar with the process of starting with a large sample group of NiMH cells and matching their internal resistance (voltage under load) and runtime. There are very few factories producing just a few brands of these cells, so the same process needs to be used for all of them. Lipos are a little different. There are dozens of factories producing hundreds of brand names of lipo cells, and they vary radically in both performance and safety. The same brand name may even source cells from several different factories! Making sure the pack containing multiple cells will perform consistently with the cells inside "in balance" is an issue that is totally dependent on the individual pack. As stated above - some you’ll never have to worry about, some you’ll NEED to worry about from day one.
One of the main Lipo brand folks and I discussed the balancing ports on their packs a while back, and he dubbed them the "PPP" ports. "PPP" standing for Paranoid Placation Ports. In other words - they are only there to satisfy the few overly concerned folks, and largely go not only unused, but aren't even recommended to be used from the factory brand itself.
So basically - with good packs in the first place, don't worry about it.
Does everyone balance their batteries?