I have had my base fixed twice - both under warranty. The first time was to get a code update (required a tech to perform), the second time was a dead base. A Lionel technician informed the charging circuit was the probable cause of failure because it is not designed to self regulate itself. I don't know if that was the actual failure mode, but I no longer use the base to charge the remote batteries.
What is the concensus?
Since I sent it back I told them to also look to see if the charging circuit needed to be looked at. When I got it back, I felt obligated to test it. It did charge the remote but when I returned the next day it would no longer power up. The law of 20/20 hindsight comes to mind. I certianly will not use the new unit for charging. The first thing I did to the new unit is tape over the contacts and flip the switch on the back.