I have a merc-o-tronic model 9800 that runs on the internal battery or 12 Volt external battery. I need any information that I can get on it. does the functions that normally use 120 volt work on battery power? If so which battery. any info would be appreciated. Gary
Not sure what you need, I use a 7.5 volt rechargeable model car battery. It cost about $15 with charger. The 120 volt AC is used in testing capacitors and 7.5 volt DC for coil test.