. C rating is the measure of the batteries ability to hold rated voltage at a current. You are not drawing anywhere near the current that your existing batteries are capable of so you wont see a significant voltage increase. Higher c rated packs are generally more fragile and wont take as much abuse either. Also c rating has nothing to do with the batteries ability to transfer heat away as it discharges. So if you are operating at the higher current levels of a high c pack you will probably melt it down and ruin it in a few flights unless you have some good cooling air flow. And i mean alot!!!