What can you do with your LEGO® City Trains? How do you check batteries or add lights? Find answers to frequently asked questions about old and new LEGO® City Trains, with step-by-step troubleshooting guides and tips for your toy trains, tracks, and Powered Up motors. Pick a question to unfold the answer.
1. Lift the LEGO Powered Up Smarthub compartment from the train.
2. Remove the two screws on the bottom of the Smarthub with a screwdriver. (Kids: You may want to ask your parents to help you with this step.)
3. Replace all six batteries with new, high-quality AAA alkaline batteries.
The LEGO Smarthub and the remote control work best with AAA batteries that provide 1.5 volts each. This is because the train motor requires almost 9 volts (6 x 1.5 volts) to work properly. Rechargeable AAA batteries usually only provide 1.2 volts each – that only gives you a total of 7.2 volts, which is not enough power to run the train.
Some brands have slightly different designs and will work better than others. Batteries with a slightly larger positive output (the end of the battery with the + sign) often work better with the connectors of our Powered Up components. So if your components are not lighting up, you might want to try a different brand with a bigger positive output than the one you’re using. As a rule of thumb, it’s not a good idea to mix brands or old and new batteries.