My 1280-x battery pack has started shorting out against one of the two voltage poles going into the internal section of the detector. It fried the battery pack holder. Same thing happened to the next holder. I now use a plastic insert to protect against this, isolating the battery holder from the two main voltage inputs, but what have I done to cause this? I bought it used and I went out a few times with no problem. Help !!!!! Is the Fisher battery holder different from the usual 8 pack battery holder?