@prrhorseshoecurve a special shout out for your comment on the forum a few weeks back about removing batteries from 3rd Rail (and any TMCC locomotive)! I took today and removed the batteries from 12 of my 19 3rd Rail three rail locomotives that were more than just a few years old. The oldest ones being my Amtrak and Penn Central FL9s along with my ATSF FTs and first run SP&S E7 all had batteries that had started to leak. I was lucky enough to catch them in time. The biggest challenge was on those early models is that I had to remove the shell from the chassis to get to the battery. Later models don't require that. Interestingly enough, my SD7 didn't have a battery.
It was an interesting lesson in battery location. The FT battery is located in the nose and under the cab. On the E7 and FL9 they are centrally located.
Simply a word to the wise, make sure you check your TMCC locomotives and make sure your batteries are in good condition. Protect your investment. My goal is to replace all of these with the non battery upgrade, but with the number of locomotives that will be an ongoing project considering this doesn't include my Atlas locomotives.