Most likely the notification is ON, right? See the following screenshot:
Also make sure to critical battery level action is set to sleep instead of shutdown and low battery level action set to "do nothing", see the below given screenshot:
If all the settings are OK, then make sure the battery icon is properly shown in the system tray. If this doesn't show then go to your device manager and click on the icon "scan for new hardware", after that your battery icon will be shown in the system tray.
Keep me updated.