Man, I have this info (battery drain) penciled on my XJS electr diagrams to fastidious detail, circuit by circuit, yet I have nothing of that on my XJR.

I have an eight month old Bosh battery (2002 XJR) and it appears to be quitting on me. I'd be surprised if it was the battery this early in life. I charged it last night to about 12.4 v and today, although it did start the car this afternoon, the battery by itself was reading only 11.5 volts. When running, it reads 13.3 v across the battery, not bad, although my old Sears wheeled charger plants all of its 14.7 volts across the battery, confirmed that last night. The machine is as good starting as it is charging.

I measured battery drain and it gives my two readings: One is 96ma for about 30 seconds, then it switches to just 46ma for 20 seconds, or so. It continues this patewrn. The 46 should be fine, but 96ma is too much, so something is wrong. Three days of no driving it and it's back to square one.

Anybody has experienced or heard about this pattern? Any "official" numbers on battery drain?
Thanks in advance.
Cheers,

 

A 30ma drain has been referred to many times but I am unsure whether that is an official Jaguar number or not. The car has a couple of sleep levels ie: after a few seconds and after a few minutes. The security control module manages this and will not go completely to sleep with the key in the ignition. In fact, if the key 'door' that covers the slot does not do so the SCM will not go to sleep.

I agree that 96ma is too much but your your description leaves me with the thought that there is something else amiss. The 13.3v running is not adequate. It needs to be above 14 and ideally 14.7v.

 

On my 98 XJR, the interior lights stay on for 20 or 30 seconds if I do not lock the car. Obvious in the dark, not so in daylight.
An easy way to check that the glove box or boot / trunk light is not stuck on is to set your phone to record video and shut it in. On play back it is obvious if the light goes out, or not.