Landrover Low battery please start engine. Error message cause and auxiliary battery location.

Are you getting an error message on your Landrover Discovery 4 warning of "Low Battery Please Start Engine" and the Stop/Start warning light showing. The auxiliary battery is located under the plastic cover on the opposite side to the main battery.

[SPY]

@Yew Tree Garage
I have a Range Rover L322, and mine is starting to not start up that's the main battery was new 12 months ago, when I attach a booster pack to it, it starts no problem with hardly any drain to the booster maybe 1% less than 100.
Is this auxiliary battery also on the L322 model?, its 2007 diesil v8 3.6 i think

[Agent_Strongman]

Life saver!! Been bugging me for a week

[MrAnderson]

I’m having this same warning come up on my Velar - 2018 - D300 after 2 to 4 days of it standing which is odd.
Had the battery checked for health and they said it’s good health, nothing wrong with it.
Does the Velar have the same little battery hidden away?
Someone told me that it’s an earthing issue.

[jamesbarratt]

Not exactly true. Did a test on both batteries using my Autel Ultra. Both checked out fine. Personally I am thinking its a software issue. Early days on this fault though.

[Redbulllad]

That’s the stop/start battery, I’ve got the same warning light yet both battery’s are testing fine…

[rockingmusiccityrealtor]

I'm having trouble finding any info on this Aux Battery. I need to replace mine and no one seems to know what it is or where I can find one. DO you have a better description or part number available?