Okay, after finally getting my driver's seat issue solved I took my newly acquired 2000 S Type for a drive yesterday. It was an inaugural run and it ran like a champion. I stopped at a couple of places and it started up again each time after the short pit stop. I put about fifty kilometres on it, about half of that on the highway and the rest around town, and then I left it in the garage overnight with the battery connected.

When I tried to start it this morning, nothing happened. I checked the battery and it was totally flat. I have now disconnected it and am recharging it with my trickle charger.

I was wary of the battery because when I bought the car from the local auction a month ago they were continually having problems with it running down. Consequently I always disconnected the battery until I was ready to give the car a try. I understand the battery is new but I will take it out and have it checked somewhere today. I suspect the battery is okay, however, and if so, how should I go about trying to find the source of the battery drain.

I have been reading some of the posts and some people seem to believe that one requires a battery maintainer with these cars when they are not being used in the winter. I was planning to just disconnect the battery until I am ready to drive it in the spring but that might not be such a good plan given the complex electronics.

Bob Pellow
Parksville, Canada

 

Note: The service life of the battery is dependent on its condition of charge.

It must always be sufficiently charged for the battery to last an optimum length of time. We recommend that the battery charge is checked frequently if the vehicle is used mostly for short distance trips, or if it is not used for long periods of time.

(Owners Manual)

 

A disconnected battery may/may not stay sufficiently charged over the winter to start the car in the spring. Even if it does, some of the settings will need to be re-programmed.

A battery tender makes good sense. I have four of them.

 

The best thing to do is find the source of the drain or not charging. Start by checking the battery voltage then start the car and verify that the battery is being charged. The battery should be around 12.4v static and around 13+/- a few volts with the engine running. If you are not handy with a volt meter take it to a garage or AutoZone and have them check it both ways.

Gus
www.jagrepair.com

 

Normal 30mA drain is enough over the course of months or storage to impact battery. A CTEK MUS 4.3 is less than $50, and a worthwhile investment to thwart sulfating.

 

hi Gus, David and Mike,
Well, I had the battery checked out at the local Canadian Tire outlet and they pronounced it a good battery with lots of life left in it [didn't charge me for the check, by the way--kudos to Crappy Tire].

I doubt that a battery maintainer would be my solution at this point in the diagnosis of this particular problem. I will get one once I have found the source of the electrical drain. I will be looking at the schematic today and seeing what fuses I can pull to isolate a potential culprit.

If you have any prime suspects in mind, please let me know.

The car was a beauty to drive. Really looking forward to driving it next spring and summer. Very nice British Racing Green exterior and cashmere interior. I won't let it experience a wet west coast winter. My old Volvo will have to put up with that.

Thanks for your inputs. Much appreciated.

Bob

 

There are many threads with great details about batteries going flat so you can get all the answers using Search

 

Quiescent current drain is part of the manner in which Jaguar has designed these vehicles. You can find technical resources on how to determine this drain using the service manual. Also, see this TSB;

http://www.jagrepair.com/images/TSB/...%20Current.pdf

 

Did they check the charging system at the same time? This link will take you to a wiring diagram for your car.

Link http://jagrepair.com/images/AutoRepa...01999.25en.pdf

This other link is for a testing procedure.

Link http://jagrepair.com/images/AutoRepa...%20Testing.pdf

Let us know what you find.

 

Hello Box, Mikey, Gus and JagV8,

Okay, I have learned that the ignition key's electrical component is a possible culprit, that I do need to get a battery maintainer, and that the charging system might be suspect as well.

I plan to start today by following Gus's advice to check the battery in its static state and while the engine is running. This will provide me with the information I need to go forward with other checks. I have printed the Battery Care and Testing Manual and the S414-01 technical bulletin, Battery-Quiescent Drain Current-Specifications, so kindly provided by Gus and Box. I will try to implement the checks so provided over the next week or so.

I am suspicioning [did I just create a new word?] that the battery has been dropping below a certain level thus 'waking' the car and then it running the battery down overnight whilst 'awake'. Thus the need for a maintainer. I plan to run the car daily once the weather improves next spring. Should all work out, would I/should I keep using the maintainer and plugging the car in every night?

Thanks for all of your informative replies.

Bob Pellow
Parksville

 

If you're going to run the engine just for the sake of running the engine to charge the battery, then no, this is a very bad practice.

Fix the basic drainage problem and start the engine only if you're going to actually drive the car a good distance.

I don't plug my car in except during winter dormant storage. It gets used on average once a week during the summer.

 

Or... if it's to be driven daily that is OK but until then a device as suggested would be wise.

 

The findings were as follows:

1. not running: 10.5 volts
2. idling: 13.5 volts

Because the battery did not seem to have been fully charged, I charged the battery with my trickle charger and the following was the result:

1. not running: 13.5 volts
2. idling: 14.0 volts

I measured by simply putting the positive lead of the multi-meter to the positive terminal of the battery and the negative to the negative post. Battery was fully connected to the car in both tests. It would seem that the charging system is working from these measurements. I will try to do the more complicated checks supplied by the Jaguar service bulletins later this week. Would you be able to tell me what SCP stands for, by the way?

Bob

 

Bob, the regulator is located on the 2000 MY in the alternator itself, and determines voltage based on load and temp. This voltage will be different depending on those variables. You will need a carbon pile to place load on the battery, and an amp clamp while the vehicle is running to determine a better understanding of the alternator's output. You can also do point to point checks from the service literature. There have been some owners who have reported issues with this regulator in the S-Types, and can cause draw against the battery when the vehicle is not running. However, the quiescent current draw tests need to be used to determine if this is actually the case.

BTW, the SCP network in Jaguar's is the Standard Corporate Protocol used between modules on the vehicle.

 

Using the S414-01 technical bulletin specifications, which are as follows:
TIME FROM IGNITION OFF & TOTAL CURRENT DRAIN
CLOSING LAST DOOR

immediate 4 amps and above
0 to 2.5 minutes 3 amps and above
2.5 to 7.5 minutes up to 2.5 amps
7.5 to 30 minutes up to 2.0 amps
30 to 40 minutes up to 0.8 amps
40 minutes plus 0.30 amps

I tried the test three times and got the following results:

immediate 5 amps 4 amps flashed to 8 amps
0 to 2.5 min. 2.15 amps 2.8-3.2 amps*2.6-3.0 amps*
2.5 to 7.5 min. 2.10 amps 2.6-3.1 amps*2.6-3.0 amps*
7.5 to 30 min. 2.0 amps n/a n/a
30 to 40 min. 2.0 amps n/a n/a
40+ min. n/a n/a 2.2 amps (60 minutes)
2.1 amps (3 hours 40 mins)

n/a not done
* oscillating

I will try to reset everything again and see what results but I am getting the impression that it is draining the battery at about two amps even after several hours of quiescent sitting. The bulletin says that after forty minutes the drain should not exceed 30 microamps. I tried to follow the instructions for each test but was sometimes distracted, particularly on tests two and three. Not sure what the oscillating means. On every test the meter would bang over to the extreme right when first connected but would then revert to four or six amps briefly. When the interior lights extinguished themselves the drain would drop about two amps.

I would take it that I should start pulling fuses but the Bulletin says I should use a clamp from the meter [whatever that is]. I am using a simple 0 to ten amps ammeter to take these readings. I adjusted the zero point after the first readings so they could be slightly underreading.

 

Sorry about the results table. It looked more coherent when I was typing it. I will try again at a later date to produce more coherent results

 

Essentially the system is draining 2 amps and this is running the battery down. TSB S414-01 showed me how to check the system but not how to find the source of the drain. Is there another TSB that furnishes this information. I have looked through the manual that I downloaded but have not found a troubleshooting section to date. Will have another look today.

 

There are quite a few threads about drains with very detailed suggestions that go on for many posts so you can just read and follow them. Don't expect it to be easy - though occasionally it is.

 

Suggest you search on "Quiescent Current Drain . . . " where many of us, including those advising you here, collaborated to set down a boots-and-all approach to measuring, diagnosing, then systematically fault finding each section of the car's electrics/electronics to isolate any excess drain.

In one of your earlier posts you brushed against a commonly overlooked problem - ensuring that the vehicle is allowed to fully descend into sleep mode, chasing the benchmark "less than 30mA after 60 minutes". Basics like leaving a door or boot/trunk open are a sure fire way to capture erroneous readings.

Further advice . . . from the electrical wiring diagrams, you will note that these cars (like most modern digital age devices) are wired via fuses to be "hot" at all times (no switches in power feeds). Any ON/OFF function, maybe by manual switch but more commonly by programmed controller, is performed by "pulling" the return power lead or connection to earth.

In particular, I commend the circuit by circuit approach if there is excessive drain - either pulling a single fuse at a time - or, as advocated by John (I think) by measuring the mV drop across each fuse in situ. Then, post back results.

Cheers,

Ken

 

And don't rush. Be logical, take time, make notes.