I just wanted to post this and maybe help save a helicopter. Last week I was flying my Raptor 90, it has a Duralite 7.4v 4000Mah battery and a 5.1 Duralite regulator. On the 3rd flight all of a sudden it wouldn't go nose right, I went into a hover, went nose left fine, tried to go right and nothing. I started to get it down on the ground as quick as I could and 10 feet off the deck it whipped around a couple rotations and stopped. All most got the skids on the ground and it started whiping around again, not knowing the cause, I throttled up and got some altitude to do a auto. It straighten out and when I was coming in on the auto it started spinning again. I got lucky and still got it on it's skids (I'll admit it was luck). I figured if it did it on the auto it was probably electrical, after checking the servo, gyro and connectors everything seemed fine. Checked all the links and tail and that was all good. checked the battery and it seemed kinda low for only a few flights. I put a full charge on it and it checked out at 8.4v, put a 1 amp load on it and it dropped to 7.4, discharged it a little and put a 1 amp load on it and it went down to 6.7v. I know it was a long story but wanted to share it and load test your batteries. I replaced the pack and put some flights on it today and everything is perfect.