That probably wouldn't work on the LR4, since all 12V sockets in the car switch off via timed relays a few minutes after you shut off the engine. Conditioning / charging the battery regularly is a good idea however, especially if you go days without driving, or drive short distance commutes on a regular basis, as the battery may not get enough time to recharge properly when engine and alternator are running. I have a relatively inexpensive Shumacher SC-1200A-CA auto-switching rapid charger / trickle charger - with alligator clips to connect it directly to the battery terminals in the engine, and it works quite well. I try to give both my main and auxiliary AGM batteries a charge once a week in my garage (the Shumacher unit has a switch for flooded, deep cycle / AGM and gel cell types) to keep them conditioned and in tip-top shape.
One thing Land Rover recommends when using a battery charger or maintainer is to connect the negative alligator clip to a grounding point inside the engine (there are a couple of them easily accessible in front of the battery compartment), rather than directly to the negative terminal on the battery itself. This is due to the BMS - Battery Monitoring System - module mounted on the negative lead of the battery, which may not detect current flow supplied by the charger otherwise and may retain wrong battery conditions info as a result.
Please note I have a 2013 with no Stop/Start system - I do have a secondary battery, but it's an aftermarket unit that runs my refrigerator, cameras and other devices separately and is connected to the main / cranking one and alternator with a Traxide isolator... Don't know if different precautions and procedures would have to be taken when charging the battery of a 2014+ LR4 fitted with the Stop/Start system with an aftermarket battery charger. Probably not, but you may want to check on TOPIx or ask your dealer first.
