Electrics (battery )

[joejag308]

With these cars having so much depending on the battery it makes sense to keep a check on the battery.
Mine is / Was on its second battery in 25000 miles.
I went for a battery and was told its ok, the guy at the motor factors tried it on his hand held meter, holding charge, no drain plenty of power in it.
However he did tell me to get my alternator checked, this i did and it was charging ok........what now then?
The suggestions of help from friends was welcome, but all were to no avail i still had battery drain overnight.
One suggestion was did i keep the automatic headlights and wipers in the auto position?...this used to be a problem evidently with older models the auto selection kept the computers going after switch off....not so now however the circuitry has been changed.
In the end i went to a "car electrician" not a do it all guy but a out and out car electrician....he did what we used to do years ago.....a drop test...the one with the two pokers and a gauge in the middle.........straight away.....
Yer "batteries goosed" he said cells gone......so i bought a battery from him and all seems well.....an extra strength heavy duty model.
The factor lost a sale of £100 i had a shedload of running about, looking for a simple thing i seemed to know about from the off....so if you have elecrical probs go to a "car electrician".......an in line trickle charger is good as an extra bonus the best one by far evidently for our problems is the CTEK XS3600 ABOUT £47..........WINTER IS COMING

[Brakebuster]

i too had to have a new battery for my XJ8,

i went out one morning ( not cold ) she tried to turn over and then just died, all i got was a clicking from lots of relays and fault codes being thrown into the dash for me to have a heart attack over,

i got ( what i thought was ) a charged battery and connected it, it turned over a few times but wouldnt start , hmm

called the RAC , lol

man turns up and knew straight away what the prob was, the car had flooded due to the lack of power in the battery to turn it over with sufficient power to start it and clear the cylinders, the resulting flooding had ' washed ' the bores of any oil and so a loss of compression was contributing to the problem

so it was spark plus out on the one bank, and yes, they were soaked, squirted a little engine oil into each cylinder through the spark plug hole and put the plugs back in, put on his charger/starter from his van and after a few splutter she fired into life, this cleaned and oiled the other bank and we left her running for a few mins

i had already instructed the RAC to bring a new battery with them which he installed and is guaranteed for three years , all voltages from the alternator etc were fine,

and now have a reliable fully working system

all fault codes were due to low voltage and have been reset automatically

the battery test showed voltage, but no power as a cell had gone down to nothing, but only his testing unit would show this

BB

[paulbarrie]

I found that whilst my seat was returning to memory position, I got nothing from turning the starter key but silence. It was only after the seat etc had returned to preset position the the engine started. I assumed rightly or wrongly that whilst the battery power was being used by the seat motors, the starter motor wouldn't turn. Tried charging battery, after which all seemed fine but as I do a lot of short journeys it soon started over again. Had battery tested and found duff cell. Replaced battery and now fine again but I will put it on charge every now and again because of short journey use.

[joejag308]

Paul.........re your new battery lasting lomher have a look at....
CTEK XS3600 .........ABOUT £47......... this will keep your battery topped up at all times when not geing used. Joe

[paulbarrie]

Thanks for the advice. At the moment I use a Halfords Automatic charger but will check out the model suggested. I have the problem that I don't have a garage, just a carport and access to a mains supply is via a 50 foot extension lead, so it's a pain to set up for recharge. I do use the car most day's of the week but some day's just to & from station car park, approx. 2 miles, which in the winter months with all lights, heater, seat warmer etc blazing away, it's really no wonder that the battery needs a top up every now and again.

[atlegranby]

HELP!!!!
I got a big problem with my carging/battery.
After i purshased my car last August i found my battery to be weak. After a couple of months of weeken-charging I finaly changed it in February. Problem solved
But, as you know, I got a 1972 XJ6 and a Triumph GT6 who I am using in the summertime, and this causes the 308 to stand for a week or so....
My first notice of something was wrong came in June. The 308 had stand for aprox 10 days, and now it was flat battery. I charge it (a CTECK charger) and probleme solved again.
Now it is wintertime, and I got problem with the battery again. It will not hold power for a weekeng of no use of the car and no extra charging.
I got a new battery from the dealer but he claim there is nothing vrong with the one I purchased in February. Nothing other than discharged....

So my question is:
Is there a known problem who causes the battery to drain?

Ps.
What is correct (Jag spec) size of the battery in amps pr/h.?

[joejag308]

Artle..........look under electrical heading on the BB and all the answers are in there re the battery problems..........Joe

[atlegranby]

Joe
I did read it all, but was not able to pinpoint the exack problem, or a well-known comon problem.

What did I miss?

[joejag308]

Atle, further to the info i posted on battery drain. I found it was the battery itself in my case that was causing it, on a hand held meter the faults didn't materialise, but on the old "drop test" (basically the two linked pokers with a gauge in the middle ) showed up a dead cell or two.

But that is not really battery drain....that was a fault with the battery ......so i had a chat around and found that XK8s also have this problem..........in their forum under electrics and battery drain items it give a detailed explanation of several causes and remedies for the problem.......you being more informed than i am in these matters will no doubt be able to understand what the problems and remedies are....................so have a look see.......Joe

[joejag308]

Just when i thought my problems were solved with the flat battery issue only two days ago after leaving the car stood for three days i went to start the car and what did i get .........a flat battery. The battery i had fitted last summer was a large (diesel ) type of battery this was to overcome the discharge problem the cars seem to have.
Now all the info i entered in the forum seems to be redundant. What i did do was charge the battery back up and leave the terminals unconnected so it was stood in the boot unconnected.
Then i tested the battery after two days and it was still fully charged.
This points to me as though we do have a discharge problem while the 308 are stood for a few days. Im no electrician, car or otherwise so it looks like another trip to the car electrician...unless one of you intrepid band of experts can solve my problem. ........Joe

[Brakebuster]

hmmmm

sounds like we have a problem to solve

being an electrician.... honest ...... the first thing to do is identify the drain when everything is ' turned off ' this can be done via a multimeter measuring amps , it needs to be put ' in circuit ' with the cars electrical system to read any power usage,

the main problem with this is turning off or disabling everything that should be on

for example, the clock needs to work, the ecu needs power , the alarm system and possibly other unknown systems ,

the main culprits after these are sorted are interior lights, like the boot , and or alarm power drains, after that its a case of broken wires which may be shorting to the body causing the problem

have you checked the problematic boot hinge wiring for broken or shorted wires ?

if not easily found, you may be into expensive auto-electricain hours to find it

BB

as a small afterthought....
testing the battery for voltage does not show if it is duff or no. you need to do a drop test with a battery tester to see if the amps are good, good voltage but bad amps will not turn over an engine, cold weather kills the amps , then the voltage,

Halfords would do this test for free if you indicated you might buy another battery from them ,
diesel rated batteries deliver their power in a different way to high rated petrol engine batteries,
go to Jag, and get the right battery, they are cheaper than Halfords to.........

[joejag308]

BB i have reconnected the charged battery and it almost throws the engine down the drive, it doesnt even go one revolution without it firing, that's after leaving the charged battery unconnected for three days. Its the same battery that drained whilst insitu........i always set the alarm on the deadlock too, the clock of course is working so is the alarm warning light the interior lighting is switched off i have no other spurious equipment connected.........the battery is a heavy duty meant for a diesel.
That's all i can think of ........it does seem now the battery has been unattached for three days and holding charge that it is ok. I think i will get myself one of those Cetec units to keep the battery topped up while its stood idle.......i don't rule out i have done something stupid to make it discharge.........what i don't know, but these days since retiring things don't seem to go as smooth ........if you know what i mean????.....Joe

[BrianG]

Joe,

One less obvious place to check for current drain is the glove box light. I don't know if your Daimler is any better built than my XJ8, but the glovebox door is very flimsy and can twist slightly if you don't push it shut in the centre. This can prevent the left hand door catch plunger from engaging properly on the switch for the glovebox lamp, so that it stays on. If this happens you might, as I did, get the giveaway clue of seeing a faint glimmer of light from around the edge of the door.
Fortunately I found this before my battery ran flat. It seems (on my car at least) that trying to close the door with a gentle push form the drivers seat tends to provoke this condition, as you can't really push the door in the middle. Now I always slam my glovebox shut and then push on the left hand end just to make sure!

[joejag308]

Brian many thanks for that i will try anything its one of those things that we think we have cured then it does it again. So any comments are appreciated........its quite a popular problem others have had sometimes with different results.......still what do you expect for a mere sixty odd thousand pounds......perfection? ......ha ha ha......Joe

[ptjs1]

Joe,

A battery going flat after 3 days means you've either got a duff battery or you've got an inappropriate current drain. Assuming that after 3 days when charged and disconnected it's still fine, then that would seem to indicate a drain somewhere when connected.

BB has suggested checking for a drain using an ammeter. I'm sure that's the right way to go. I would suggest you:

Connect your ammeter and see if the load is inappropriate for the circuits that you expect to be live. (When you do this, confuse the boot into thinking it is shut and also alarm the car.) If the load is fine, get a discharge test done on the battery. However, if the load is unacceptable, then start pulling fuses until the load drops. Start with the obvious ones, alarm, boot light, glovebox light, interior lights, clock, stereo. In this way, you should find the faulty circuit.

Good luck

Paul