This is on my 2002 XJ8 LS swap so some different wiring. Twice battery absolutely dead after a weekend or overnight sit. New battery. Hooked up ammeter. All draws off including boot lights. When connect power jump to 2.5 amps as CD player turns on, soon goes to .5 amps, and then to 60 milliamps. Checked for hours. Stayed at 60 milliamps. Haven’t started pulling fuses because stays at 60 milliamps. Stumped. Just ordered remote battery disconnect until I figure out.

 

Somewhere around 50 MA would be considered a normal draw. However
the batteries in these cars are highly susceptible to a "tipping point" in the
required voltage to actually start the engine. Such a draw is very difficult
to pinpoint and some members have found using a solar panel is an effective
method to counteract a parasitic draw.

 

trunk, glove box, interior light, something is causing a draw down: time to start shutting down major circuits and using your ammeter to find the offending . .

Might also look for a bare wire . . .

 

It's something intermittent. Like I said, had power running through an ammeter and checked every 30 minutes for hours. Never changed from 60mA. My normal may be different from standard XJ8 because LS ECU instead of Jag. I've thought of a bare or frayed wire not always contacting.

 

Installed a remote controlled battery shutoff. Now don’t have to manually disconnect battery until figure out draw down.

 

That looks a neat way of doing things.

 

There are only a couple battery/constant on circuits for the LS swap wiring. If I recall, there are two for the 6L80E and at least one for the ECU itself so checking the LS-related wiring should be pretty easy. Given you swapped interiors, do you recall if you had any questionable connectors/connections at that time? Lots would have been disconnected/reconnected... My gut is that the draw is body/chassis related and not LS-swap wiring...

 

It fits fine under the cover. $59 on Amazon. Another with less amp capacity was maybe $10 cheaper.

 

I’m,Ike the remote battery disconnect. Good security item.

as far as isolating the parasitic draw. Keep the ammeter hoked up, and start pulling fuses. Might help to have a partner to read the meter as you pull each fuse.

 

See my second post. After short time, went to 60 mA for hours. Looking at borrowing an ammeter that logs so I can leave overnight. Guessing the draw is intermittent which is hard to figure out. Been on lookout for the gremlin from the Bugs Bunny cartoon.

 

Have you monitored the state of charge battery voltage after an hour or two? Have you done a state of charge and battery condition test?
It's best to rule out a self discharging battery from all your testing. Unfortunately if this is a random power draw at an unknown time you have to set up an oscilloscope test with an amp clamp to monitor overnight. It will data log anything odd that happens. if the battery voltage drops to a certain point it actually wakes up modules. I've also heard of aftermarket alarm systems waking up modules.

 

There used to be a thing with Range Rovers where powerlines would wake up the alarm modules & make the battery go flat within a day or two. It's odd what can screw your car up at times.

 

Had this on mine, , XJR 2001..told they should have 35-50mA drain. Mine had a bout 80 and after a week was flat, turns out it was a fault within the alarm security module. In fact, when my mechanic was investigating it, the bloody thing caught fire! ….
I got one from a scrapyard and since changing it, she’s now fine.
also, if you leave these girls unlocked for long periods it drains more than in locked mode, because the security module is constantly in search mode for the key.
cheers

 

Looks like this ought to come standard on every Jag!

I have a the quick-connect cabling for a battery tender wired into my battery and, being no electrical genius, wonder if I were to use this Matell device whether I would need to take off the battery tender wiring and then use the "clamps" whenever I wanted to give the battery a few hours of "tending?" I wonder also whether with this Matell device I would even need the tender at all?

As I said, electricity and me are not generally on speaking terms, so any guidance appreciated.

 

Provided your tender was wired on the battery side of the cut off (ie directly to the battery terminals), it'd make no change to how things worked.

 

Thanks. I believe I have the negative lead fastened to a body ground adjacent to the negative terminal. I expect I could just move that over to the negative terminal, then install the battery cutoff device as pictured.

 

Two things come to mind as I've seen them over the years, but they are rare occurences. #1 The Stero / CD players, (not brand specific) are known for not shutting down completely. Sometimes producing a slight drain that takes 2 or 3 days of sitting to actully kill the battery. #2 the regulator in the Alternator itself has been known to cause a drain. GM Delco Alternators have had that problem for a long time. It's not real common but it does happen. Just a couple things I hadn't heard anyone else mention. Hope it helps.

Jack

 

Thanks. I'll look into that. Been using remote disconnect every day. Only inconvience with that is clock is off. Still waiting on borrowing logging ammeter. Two times happened it drained battery so low it trashed battery and would not take a charge. EverStart Platinum so Walmart has replaced for free both times but still don't like being that guy.

 

You need to find the source of the drain, a cut off device is not the answer. IMHO

 

I'm sure you've checked this already; sometimes the glove box does not fully latch on the left side and the light stays on. Battery drain follows! Have seen it happen and now soundly close the door on my cars.