I killed the battery today. My LR3 had been on jack stands while I've been working on it for a few days. I turned the interior lights off since I had the tailgate down the entire time. The doors were locked at night. I'm wondering if the computers don't sleep and drain the battery since it is on jack stands with all the wheels off the ground.

 

Any door open will keep the computers in a woken state regardless if interior lights are on or off, being on stands is unrelated.

 

Having the tailgate open keeps the ECU in an active state, increasing battery drain. This is a common complaint for the Offroading/Overlanding crowd that like to go to super remote places and cannot waste any battery power. You should have either disconnected the battery prior to working on the car, or connected a maintenance charger on the battery if you really wanted to keep all your ECU settings like the EVAP test.

 

I camp A LOT with my LR3 and the tailgate is often open all day since my kitchen module stove slides out the back. I've never had an issue, yet... But I do have an aux battery, so I can jumpstart myself if needed. I would think its less an ECU (electronic engine control unit) issue and more of a CJB/Infomat system drain. When a door is opened, the infomat system awakes which means onboard nav/radio/amp/phone - those all come online and thats a substantial power load. Makes me think I should put the infomat relay on a switch for camping use.

 

Thanks, good to know an open tailgate keeps the ECU awake.