Funny - I've flown my Raptor 50 for a week straight, and had to recharge the heli a couple times whereas my DX7 worked the whole time on a single charge - I don't think my voltage ever went below 10V. If you're able to get your DX7 voltage below that in a week then you gotta be doing a whole lot of flying with it. Typically, I don't even worry about my DX7 Voltage - It stays strong for long for me.