When you plug in the charger the LED lights turn red and green and the fan will give a little spin indicating the charger is activated and ready.
When you connect the battery it may take some time before the charging starts. You should hear 2-3 click sounds and the LED lights will both turn red, that indicates that the battery is properly charging. When the battery is fully charged, the LED lights will revert back to red and green.
If the battery is in need of an optimization, charging may not initiate, especially if you are using the speed charger. You can access the "Battery Optimizer" feature directly from the home screen in the Radinn app, and it contains all the information you need on how to get started. Note that the latest update of the app is required to access this feature, and it's recommended to use the standard charger, and not the speed charger, for optimization.
It is also important to note that the battery needs time to cool off before you charge it. Riding builds up heat in the battery so if it's connected to the charger before it has had time to cool off, it might not charge.
If none of the above steps help submit a support request and we will support you. Please make sure to fill in the ID of your battery.