You can use javascript.   E.g. for Battery Status, you can use javascript to access html5 battery API.  For time, you can build javascript function to use Date() output to format a time string of your desired format for inclusion in the lockdown. 

Different implementations may result in widely varying impact to the device battery life.

Perfect! Thank you for the answer:)

Part of this has been simplified in yesterday's OEM Agent upgrade with a date / time macro. 

Please note that, as of today,  the %device_date_time% macro is supported in the latest device agents for only one or two OEM brands .   It will take some time before the feature is available for most, if not all, OEM brands.  On the contrary, most Android 5+ devices have already included the rendering engine to support industrial standard html5/javascript features.

A major problem of using default macro on lockdown menu is that special codes need to be included to refresh the display at appropriate time.  This is not a big problem for macro such as device name, as it is unlikely to be changed very often.  However, for the %device_date_time% macro,  the 'second'  portion of the timestamp gets outdated as soon as it is directly displayed in the lockdown menu.  Also, the format of the %device_date_time% macro is fixed and may not fit particular purpose unless post-processed with extra code.  The new macro is, however, very useful and handy for use to create log entries.