I have a R 127 DF Rx and plugged a JR 4.8 V. 600 M/A battery into it and the negative (brown) wire of the battery smoked. After plugging in a futaba battery (with the polarity tab) and checking out the functions the reciever is working fine on my work bench.

Im not sure what direction I had the battery plugged in but it has 3 wires, orange red and brown, the red wire (positive) is in the middle, negative wire smoked.

I have visually inspected inside the Rx and see no evidence of heat or discoloration and does not smell like it got hot. Since the Rx seems to be working fine, are chances good that I didnt hurt a thing?