So I now have two phantom lipo stock batteries that won't take a charge from the stock charger. The charge light and the 1s light on one battery and the 2s light on another flash alternating. I have looked at many youtube vidoes that point to the leads being plugged in the opposite contact (+ to - and - to +) but I'm sure this has not happened. In additioni have opened up the charger as noted in the youtube videos and checked for a burned fuse or other burned areas, but nothing was found that looked wrong. I have measured the voltage on each battery using an analog multimeter and got the expected 11.1v on one battery and about 10v on the other. The only other thing that I may think could have caused this is a large load pulled on the batteries resulting in a damaged battery. In my last flight the phantom tipped over on landing and the props started hitting the ground while still running. The quad would not shut off as it continued to try to right itself. This resulted in a high load on the battery for the two motors on that side. After this I look the battery inside to charge, and the error explained above occured. So what do you think? Did I damage the battery during flight or did the charger fry my two batteries? Should I get a charger with an electronic controller? Thanks for any input.