When I shut the engine off and lock the car, is there a time after which the power in the car goes off?
Namely I'm interested in the overhead console.

I'm afraid the console might actually stay On, because of the intrusion detecting system that some cars had. (Mine doesn't.)

Is there an authoritative source for such information?

 

OK, mere minutes after I posted the message while sitting in the car checking the multimeter the voltage dropped...
30 minutes seems to be the answer

 

For most things, that sounds about right. And it IS documented. In a nearly 1200 page publication. Somewhere.

That said?

Even if it did NOT have anti-theft/security break-in monitoring (and you might still have more of that than you think you have) ANY motor vehicle that supports a remote key fob MUST have at least a "watchdog timer" circuit that periodically wakes-up the transceiver that listens for remote commands. ELSE leave that system active 24 X 365.

So those are your 'minimum' sources of battery drain whilst allegedly "idle".

A good grade of battery sustainer/maintainer charging device has made it a non-issue for me, even though the X350 was driven only 83 miles between annual safety inspections last year.

Stale fuel is a different challenge. Same again, "flat spotting" tires.

DRIVE a Jaguar.. or go broke, anyway!

Great road cars. Only so-so as lawn decorations. S**t lousy as paperweights.

 

Oops, good point 👍

While I significantly reduced how much I drive since I got the Jag, it still gets driven at least once per week. I've chosen this day as my XJR-day, which simply means I drive it to get my *** to/from work.
I don't like the idea of adding too much kilometers on the Jag by commuting to work. Long trips (to visit the family) are when I hop in the Jag of course.

Anyways, I was worried about the idle-draw because I know very little about electricity/current/voltage, and I am in the process of adding a custom garage door opener in place of the EuroHomeLink 2000 (and the original HomeLink before that)... Which also means I am adding a switching voltage regulator. And, knowing zero about this stuff, I was concerned about draining the battery by connecting something somehow in a stupid way...
I am hoping the drop in voltage means the regulator would starve to death before it could drain anything.

 

Pension was earned in telecoms. Done more than a few gadgets from bare electrons, 1950's to present day.

TOO DAMNED aware of all that complexity, so I use the maintainer chargers, Jaguar, Rover, MEP-803A Diesel gen set instead of bothering to grok and re-engineer some OTHER fool's already-paid-for craft.

Door opener that just clips onto the visor was also "already paid for" with the opener itself, has moved across too many different vehicles to keep count of... sometimes including my jacket or trouser pocket, given an 18-foot wide door is no fun to operate by hand.

Got FAR too many other fish to electrocute than time to reinvent that particular wheel.

NOCO Genius or similar made more sense than a watercraft-style massive switch to 100% disconnect the battery whilst parked ... thereby also confusing some of the 'con puta' gadgetry in the motorcar's monkey-circus.

Once a week recharge trip is bare minimum? I figure a battery is too flat to start the car in about two weeks, idle ...if not on charge..., and flat enough to confuse the 'lectronic con-putas after about a month, idle. Weather not even worst-case.

In my ninth year on the OEM Jaguar H8 battery. I think Yuasa made those? The maintainer charger has proven well worth having. But we have known that in the Telco biz for .. over .. 180 years, is it?

Odd side note.. Ancient Persian Empire had "primary" cell batteries made in quantity in ceramic jugs, understood series and parallel connection.

Now... if we could only figure out WTF they were DOING with them!
Might be able to challenge the Erectile Disfunction Drug patents.... off the back of "prior art"?

 

You probably just want to make sure that the voltage line you are going to tap into for your garage door remote regulator is a switched supply, that only comes on when the key is rolled to accessory or run position.
That way you should not have to worry about that accessory draining the battery when car is otherwise switched off and sitting in the garage.

 

The new GDO shall be powered by the same line the original was, i.e. the same connector even.

 

The fewer non-original pieces in my view the better. (No phone mounts for me for the same reason.)

This thing shall be hidden in the console and operated by one of the three original GDO buttons - for me that's well worth the effort. 👍
Also these wheels aren't going anywhere, thus I don't worry about moving the GDO to a new place.

 

Kyocera DuraXE & an Alcatel flip? "Phone mount" is the same one I use when afoot.

Shirt pocket!


Got the same problem, different reason. I don't soon get off my creaky, wrinkley **** ......and finish the repairs!