Low battery - new logo door welcome lights

[Bob-ski]

Help needed.
A few months ago I had a problem with the car battery. I went to the Jaguar dealer who said the new battery is needed. Car is 2019 p300 model.
I knew it is quite common issue so I paid the fortune and agreed to change the battery.
All was fine until last night when the message "low battery " appeared again on the dashboard.
I couldn't believe this.
Now here is the question. About a week ago I installed a new Jaguar logo door lights. I had these before but one stopped working so I had to got a new ones. Is it possible that new lights cause the battery problem now? Installation seems to me super easy so I don't know where the potential problem might be. Anyone with similar issue? Thanks in advance.

[cj10jeeper]

It seems very unlikely that a straight swap of door lights would themselves cause a significant drain over a week.
Interesting how long you have the doors open when fitting as that does cause a significant drain. I've seen that when detailing the car.

First thing I'd do is test the voltage now then give it a long charge, ideally 12-24 hours on a CTEK or similar and check the voltage comes back to 12.6v+ after its charged then rested and then recheck periodically afterwards when not used.
If it's dropping daily when not used then you have an issue to track down, if not then a one off.

[scm]

cj10jeeper has said it all, really. How much do you drive the car? If lots of short journeys the battery may never get a chance to be fully recharged for the stress of starting. As suggested, give it an overnight charge and diagnose from a known good starting point - it's surprising how much leaving the doors open can deplete a battery!

[MajorTom]

Good advice above. Apart from lots of short drives without additional maintenance charging with a CTEK, there are two known causes to battery drain, triggering this message:

- Plugging something into the OBDII port, preventing the car from shutting down completely. Solution - disconnect/reconnect the battery.
- Single locking the car, in some cases apparently also causing some kind of drain. Solution - double lock the car.

So if something has been plugged into OBDII port recently or if you're always single locking the car, those are also things to try.

[scm]

The telltale sign of the OBD fail is the light in the hazard lights switch never goes out after locking the car (should extinguish within about 10 minutes).

[elugelab]

If you are charging the battery with it still connected, make sure you hook up the charger via the power distribution bar and earth under the boot floor, rather than directly to the charger. If you don't do this it can confuse the battery management which then claims low battery, when it has been charged.

[scm]

... make sure you hook up the charger via the power distribution bar and earth under the boot floor, rather than directly to the charger.

"battery".

[Bob-ski]

Thank you so much guys. I will investigate further. Thank you for all your help.

[elugelab]

... make sure you hook up the charger via the power distribution bar and earth under the boot floor, rather than directly to the charger.

"battery".

Indeed

[Jaguandy]

You can also quickly connect a charger to the charging port under the bonnet.