Note that manufacturers like 3rd Rail, Weaver have had several different types of control systems over the years. If they're using the QSI boards with the 9V rechargeable battery, the BCR is a suitable replacement. If they're TMCC command models, they'd be using Lionel RailSounds, the YLB is a suitable battery for those. K-Line had older conventional sound boards that didn't use a battery and then Lionel RailSounds which would use the YLB. Any Atlas that is a TMCC model also uses Lionel RailSounds and would use the YLB. Older conventional Atlas would typically not use a battery.