The Train Control Systems KA1-P Keep-Alive® is TCS's most compact stay-alive capacitor pack — about half the size of a KA3 — feeding backup power to your DCC decoder whenever the wheels lose contact with the rails. No more stalling on dirty track, dead frogs, or insulated turnouts. The KA1 delivers roughly one-third the capacitance of a KA3/KA4, making it the go-to choice when space is tight in N and smaller HO locomotives.
This is the harness-equipped version: it ships with a 2-Pin Quick Connector Harness that plugs straight into any decoder with a compatible 2-pin Keep-Alive socket, such as the TCS T4 and other current TCS decoders — no soldering to the decoder required.
Browse more decoder add-ons in our DCC Accessories collection, shop the full Train Control Systems lineup, or pair it with a new sound decoder from our DCC Decoders collection.
What does a Keep-Alive actually do?
It stores an electrical charge and feeds it to your decoder when track power drops out, so the locomotive keeps moving and its lights and sound stay on across dirty track, frogs, and gaps.
Will the KA1-P plug into my decoder?
The included 2-pin harness plugs into TCS decoders with a compatible Keep-Alive socket (such as the T4) and most current TCS decoders. For decoders without a 2-pin socket, you can solder the leads to the decoder's keep-alive pads — check your decoder's manual first.
Why choose the KA1 over a larger KA3/KA4?
The KA1 is much smaller and fits where bigger packs won't — perfect for N scale and cramped HO shells. It holds less charge, so for longer run-through use a KA3/KA4 if you have the room.
