If you are going to be using electric power much, it will behoove you to buy yourself a voltmeter. It doesn't have to be an expensive one either, even the $3/5 Harbor Freight units will do the job. Now you can measure each cell of your battery. On LiPo's, a fully charged cell will be 4.2 volts. Try to never discharge one below 3 volts/cell as that will often ruin it. And yes, it is good practice to always balance your battery when charging as, as said above, if one cell falls much below the others, you will most probably overcharge one or more cells. This is the most dangerous aspect of LiPo's (overchargeing) as that is when you can build up enough gas pressure to rupture the outside casing and possibly erupt in flame.