I have seen various causes of smoke and fires in models but what happened to me last summer was a first.

One of my club members runs a small mobile hobby store out of a trailer that he brings to the field a few times a month. I try to give him as much business as I can and on one occasion I purchased a 1400 mah NiMH Rx battery. The battery was in a sealed plastic baggie and I immediately put the battery in my jeans pocket and went over and sat down under the club shed. No sooner than I sat down I felt my rear end starting to get hot. I immediately jumped up and retrieved the smoking battery and was surprised to see the leads and plastic baggie melting and smoking. I managed to clip the leads and let the smoking remains cool on the bench. When cool, I returned the burnt mess to the seller and noted that it had never been opened. He swapped it out for a new battery which we both inspected carefully before I took it.

Because the leads were melted on the burnt battery it was deduced that the short must have occurred on or near the connector. The connector and pins looked Ok but all of the insulation was melted off the leads so it was impossible to see where the short might have originated.

Lesson learned: You can get you’re a** burned with a battery NIB.