Yes, yes, that was the point of the bit of fun I was having, explaining cordless technology that still required plugging in. I'm not sure if I should hang my head in shame or celebrate with a victory lap. Kind of like when I explained to my longsuffering children how I was shopping for a solar powered flashlight, or that I wrote my name and address on my driver's license in case I ever lost it.

My favorite groaner took place at work. In my field (aircraft maintenance), we have to be specially certified for ETOPS flights. That is short for Extended Twin Operations, allowing twin engine aircraft to fly long flights away from suitable airports, typically over the ocean. Because training is so time-consuming and expensive, we as are typically only certified for equipment that normally comes through our station. Maybe once or twice a year we'll get a plane for which nobody is locally certified. When that happens, we call another station and have them send a coup!e of certified mechanics for the day. No big deal, as long as we have enough advance notice.

Occasionally it's a last-minute change, and we have to scramble. About two years ago, we had a 747 come through on a charter, which had never been routed at our station. The 747, with 4 big engines, is absolutely not part of ETOPS, which is for twin-engine planes only. No special training or certification is required. This minor detail was lost on my foreman. I convinced him to call and request staff to handle the (non-existant) ETOPS requirements for a 747. He placed the call. Luckily he has a good sense of humor and I am still employed. But oh, it was worth it...

 

Sometimes things are lost on me............................

 

Right then, to update a little.

Had the battery tender on overnight a few days ago, went out to work the following morning and.........................no engine failsafe episodes.
Tickled it off the driveway as normal, expecting a warning, nothing. GREAT!
So I thought I'd see what would happen if I didn't use the battery tender for a few days, going back and forth to work as normal.
In my mind, if the fault came back, and the battery showed low again, then that would conclusively prove the theory, Yes?

So I haven't used the battery tender for the last 3 days, and so far, no warnings.

However.............I chickened out tonight.

Snow all over the car in the car park, front and rear de-misters on, heater blasting, lights on.
Now I know that's gonna batter the battery, so I plugged it in, just in case....................

Rag me if you like, I don't care,

 

I'd have plugged it in sooner

You could instead check the voltage in the morning, engine off, but if it's low you're kinda in a hole.

 

I did that the other day, testing the voltage, (engine off) after it was on over night, read 12.7 volts.
By over night, read about 10 hours.
Thinking about it now, I suppose I should have checked the voltage tonight before I plugged it in, maybe would have given me an indication of a near future battery failure, or as already said, not enough distance travelled.
Ho Hum, I suppose a new battery... could... be in order, and for the distance and mileage I use cars for, it would probably be the safer bet.
But given the current daily mileage I do, would it see me back in the same position??????????
When the snow and ice threat has gone I'll be back on 2 wheels on a daily basis, so the car will get even less use.
I'll have to weigh up the options I think.
It wouldn't be the first time a battery has let me down due to lack of use, it happened on the porsche when I had one of those, several times in fact.

 

Well, you need to check it after no recent charging or else when on load.

So, not just after charging it (which includes not after running the engine recently) - otherwise you see the surface charge (which is quite small but fools a meter).

 

No ragging from me.

Batteries are a forgotten item, until they fail.

Down here, battery sales soar when the cold snap arrives, and then again when the real HOT arrives, and its been that way as long as I remember.

We dont get the snow you guys get, but even my daily drivers have always had a charger top up once a week. Very few battery issues in my fleet.

 

Thanks all for the input.
I'm off again for a few days, this 4 on 4 off shifts has it's advantages.
Cars in the garage tucked up nice and warm with no tender on it, I'll check the voltage first thing before I kick it out to continue with the bikes I'm doing.
The battery must have took a beating the last 2 days, with the cold snowy weather we're getting at the moment.

Ever get that nagging doubt in the back of your head that you already know what you're going to find, but don't really want to..................

 

haha - yes, all the time!

 

Yep, but the Human race be a special breed.

 

I've left the car alone since saturday evening.
No tender attached.
Checked the battery voltage this morning.



12.1 volts

Since there is no realistic way to check the cells on these sealed batteries, I'm just going to replace it.
I'm suspecting a starting to die cell, so I'll pre-empt the forth-coming failure, which we all know will happen at the most inconvienient time, and just replace it.

 

Before you do (or I suppose after) - it could be a drain. There's a big file/thread about it (looks for quiescent).

If you do get a new battery, charge it for (say) 8 hrs because despite what sellers say they seem not to be fully charged.

 

Yes I remember Karl pointing me to that some time ago, although I can't for the life of me remember what it was for now.
Might have been while I was troubleshooting the cam codes and strange readings when I did the head gaskets, and before I found that the cams were out one tooth.
And I've seen the other threads about power drains, nightmare scenario number 1. Finding something that's not obvious.

There is a little something else that I've found out this morning as well, that has got me thinking now you've said power drain.
I opened the drivers side (UK side) passenger door and the alarm went off. Nothing unusual there, except all the other doors were locked, and that one wasn't.
So I re-armed the car, single press on the button, all the doors locked except the passenger side rear.
But when I double lock them, they all lock properly.
Don't ask me why I went for that door, I've no idea, and I can't remember why I wanted to go in that door, but I did for some reason, and that's when I found it.
IDS hasn't thrown anything up on that door module, just the drivers door module, which I don't seem to have a problem with, could be an old code.
I'll clear the codes tomorrow and do a re-scan of the system to see if anything new comes up, but again, it could be down to the battery voltage................
I've plugged the tender in this afternoon, so it'll be up to spec again in a few hours time, I'll see what happens when the battery is at it's proper voltage.
Oh these little quirks get us thinking don't they......

 

It's always tough to debug issue X if there may also be issue Y that may interfere with or even cause X.

I suppose a new battery would at least rule out a bunch of such worries, but costs money.

Though a battery from such as tayna.co.uk is cheaper than most fixes.

 

I don't mean to come across as 'flashy' or a 'money is irrelevant' type of way, and I'm not the type to throw new parts at any vehicle if it doesn't need it, but given that these cars can be hissy with suspect batteries, then the cost of a new one is something that you just have to suck up.
The saving grace is that I get my parts at trade prices, so 20 - 30% off list.
Plus as you say, if X is suspect it could be causing Y to be suspect, and by replacing X it could rectify Y.
I shall try the door when the battery is at it's proper voltage, if all works as it should, then the battery is the cause.
If it remains the same (car locked with one press of the button but door still unlocked) then I have another issue, non battery related I would guess.
I've just read Kens post on quiescent battery drain, and printed it for hopefully posterity, but if not.............troubleshooting!
Strangely enough I've recently ordered new leads for my multimeter

 

It's OK - you didn't come across that way (to me, anyway).

 

Oh no, he's given me MORE reading to do
https://www.jaguarforums.com/forum/s...attery-193787/

 

Ha ha Karl likes to hand out homework!!

 

No, you've got it all wrong. It's not homework. It's all just one facet of my patented BlameShifting(tm) protocol. What if I had said unequivocally, "Your battery is bad" and then $200 later, the fault is still there. I'd have to hang my head in shame. That's why the prudent BlameShifter(tm) says, "Read these other threads and decide for yourself." Thank me if I'm right, blame others if I'm wrong.

Amateurs try to minimize it, but blame is insidious and never diminishes. The best you can do is ruthlessly minimize "Time in Possession" and toss the hot potato to somebody else.​​​
​​When BlameShifting(tm), one must also vigorously stay alert for the BlameBoomerang(tm), which is self-explanatory.

These basic principles will serve you well in all aspects of life, especially at work. And now Grasshopper, you must take this pebble from my hand...

 

And don't I know THAT principal in the company I work for (very large multinational transport company where I'm a transport professional)..............

Anyways, doing my usual checks this morning, the weekly stuff, oil/water/tyres etc, just happened to look down the front of the engine, spotted something........you know the one.........the "whats that??????" thing.
Grabbed it, then spotted the edge of the serpentine belt.
It's a piece of that.
Been sliced off!
Looked at everything, found that the tensioner pulley wheel has play in it's bearing.
Under sprung load, it's tilting forward enough to allow the belt to run out of true and catch on the housing, slicing off a strip off the belt.
Just what I need this side of the holidays!
On to my suppliers, 4 new bearings and a new belt will be here tomorrow, post haste.
That's 2 for the idler pulleys, 1 for the tensioner pulley and 1 for spare.
Oh yeah, and the battery is at 12.15 volts after 2 days of not having the tender on it.
I was going to look at that today, see if there is a parastic drain I could quickly find but thats gone by the by now.
I did think about something that might be the cause though..........the cartridge for the cd player maybe.
Didn't have the engine failsafe warning before I loaded the cartridge with discs..................just a thought.
Probably completely wrong, but gotta start somewhere..................