Have a 2005 sport and every now and then after 20-30 minutes of driving this fault pops up. I have checked all bags and they work brilliantly everytime no struggle when highering or lowering the car, so is this fault really to do with a battery that maybe on its way out. The car starts perfect so wouldn't suggest the battery is on its last legs, anyone had and dealt with this before?

Does it coincide with a slight lurch/thud and momentary fluctuation of revs? Assuming not (as you didn't mention it) first things to check are voltage across the battery terminals first thing in the morning (look for at least 12.2 volts) before the first start and then after starting and running for a few minutes with lights and screen heater switched on (look for over 14 volts).
Also check both brake lights are working.
If all these are OK then try fitting a new brakelight switch.
If still getting the fault go to a good independent LR specialist and ask for a full diagnostic check. 2008 MY Java Black TDV8 HSE

Just had 6 new injectors so the engine runs smooth as it was juddering and it was injectors that was the problem, this HDC fault was poppoing up before that job as well though...

Had it in the specialist for that job and he said that no fault was showing up?!?!

Will get the battery checked for the levels you have mentioned

Thanks for the reply

Had these warnings up on mine 3 separate times now , first was battery, 2nd time was Upper tailgate switch, 3rd time was brake pedal switch, hope that helps. Java black 2006