As others have mentioned, the Trimetric is an excellent all-around solution for monitoring a TC's electrical system... I can't imagine not having one.
LED lights obviously have a very low amp draw. Does the Trimetric have sensitivity to these levels?
Yes, the TriMetric offers good sensitivity however the resolution of the display is limited to 0.1 units for Volts, Amps and AH (for me this is the TM's Achilles heel). Typically this resolution is sufficient however, as you can see in the photo below, I also use a precision digital Voltmeter to keep an eye on voltage.
If you're handy, installation of the TriMetric is a breeze; First locate an appropriate place to month the unit... Note that it can be mounted in an (included) enclosure on nearly any surface or flush-mounted in a panel. To monitor current, you'll need to install a shunt in your the negative battery lead, then run wires from the shunt to the monitor and from the battery (bank?) to the monitor. Then just connect the wires, program the TriMetric according the the included instructions and you'll be good to go.
Cheers,
-Mark