Hi All,

I'm new to the forum so please go easy!

I've just taken the plunge and bought a MY15 V6S with 27k on the clock and I am getting a battery drain issue that results in a "low battery please start engine" warning and eventual non starting of the car within a couple of days. Dealer has replaced battery today, but after 4 hours of getting home I checked the voltage of the battery and its already depleted to 12.48v. Every hour that goes by the battery gets further depleted and I suspect by the morning i will be getting the low battery warning again.

Others in the forum who have experienced this have suggested disconnecting the battery for a minute or two to reset the BMS because the has been solving the issue in many cases, but I haven't tried this yet as a) my car has a tracker fitted by the previous owner that is connected to the battery and apparently i need to get a specialist to remove it, and 2) my triangle hazard light goes out after a few minutes, which I believe seems to be the key indicator that a BMS reset via battery disconnect is required.

I'm really at a loss as to what to do. I love the car but can't be dealing with a totally drained battery if I don't use the car for only 3 days or so! Does anyone have any idea what would be causing my battery to drain this fast? My thoughts are it could be the tracker, but most other sources say these draw very little power when the car is off. Any input would be really greatly appreciated.

Thanks

 

You have something causing a battery drain and my prime suspect is the tracker.
Why can't you just remove it?
If you can't figure out how to remove it then an auto electrician should be able to help and maybe even remove it,
Also I struggle to see how the tracker stops you from disconnecting the battery, you don't need to disconnect either main battery terminal just the earth/ground lead where it bolts to the floor of the trunk will do the trick.

 

Thanks for the really quick reply. The tracker looks easy enough to remove but I have been told to get it done by a professional, as it may have an immobiliser device installed. I am waiting for the dealer to arrange this as they should've removed it prior to me purchasing the car. I thought the disconnecting of the battery could affect the tracker, but from what you're saying if I disconnect the negative terminal then it shouldn't? If it doesnt I will try the battery disconnect and update.

 

Yes I had considered the possibility of an immobiliser integrated into the tracker, that is why I suggested you get an auto electrician to look at it. Will be much cheaper and quicker than trying to get a/the dealer to look at it although if the auto electrician advises that something "special" needs to be done to remove the tracker then the dealer should arrange that or at least pay for it.
Do not disconnect the negative terminal (on the battery), instead follow the thick black cable which runs from the negative battery terminal to a stud on the floor of the trunk where it is held on/down by a nut. Take that nut off and remove the cable from the stud (and hold it up so it can't contact anything metal), leave it off for 30 seconds or so, then reconnect it.

 

i would just remove it.

Any tracker will have it's own battery anyway. Connection to your car battery is just to keep the trackers battery topped up.
Cutting the power by disconnecting is no different than having a flat battery with no charge through the connecting wires anyways.
On the off chance it is some how connected to an immobilizer , reconnecting it to power will disable any immobilization it may be able to do. This has already been proven by the battery swap at the dealers and given it will be a third party and the dealer didn't have any issues i doubt very much it is attached to an immobilizer. Otherwise they would be ringing you up and getting you to contact the immobilizier's company.

 

Definitely sounds like the tracker.

Also make sure that you double lock the car when you lock it. Single/double locking shouldn't make a difference for battery drain but it seems to. I used to single lock mine and kept getting the low battery warning. Since I started double locking the car the problem is gone.

 

Yep, I started double locking mine many years ago.
Coz I read that double locking shuts the electrical modules down much quicker than single locking, puts the battery system in quiescent mode (outputting 12.2v instead of 12.6v), and helps prevent battery drain.
However IIRC our Murican friends don't have this option and we don't know where the OP is, he very likely is in the good ol' US of A.

 

Thank you all for the helpful suggestions, i really appreciate it. I have been double locking the car as have read this on other threads but doesn't seem to be making any difference. Did a reading on the brand new battery this morning and it's now at 12.24v, which I think is very low? It was 12.74v when I tested it with the engine off after the new battery was installed and has discharged to 12.24v in about 18 hours. What's weird though is that the "low battery, please start engine" message isnt coming up, but i reckon it won't be long before it does. The car is still under warranty and the dealer (non Jaguar) has an obligation to fix it. They are due to authorise it going to a main dealer for diagnosis, so hopefully they can resolve it. Such a frustrating issue because the car drives fantastic. I will post the outcome.

 

Thank you all for the helpful suggestions, i really appreciate it. I have been double locking the car as have read this on other threads but doesn't seem to be making any difference. Did a reading on the brand new battery this morning and it's now at 12.24v, which I think is very low? It was 12.74v when I tested it with the engine off after the new battery was installed and has discharged to 12.24v in about 18 hours. What's weird though is that the "low battery, please start engine" message isnt coming up, but i reckon it won't be long before it does. The car is still under warranty and the dealer (non Jaguar) has an obligation to fix it. They are due to authorise it going to a main dealer for diagnosis, so hopefully they can resolve it. Such a frustrating issue because the car drives fantastic. I will post the outcome.

 

I appreciate you posting this. I just purchased a 2017 V6 S and get the same message when the car sits. I may use a battery tender while the car is in the garage. The battery is original and probably not all that healthy.

 

Yep a battery tender is a good idea.
I have been using one from the get go on my F-Type (purchased Sept 2016, Oct 2014 build) and it is still going strong with the original battery.

 

Hi All,

A little update: I have contacted the company that manufactured the tracker and they have said it can be disconnected, so I have disconnected it from the positive terminal to cut the circuit to it. Something I have noticed is that when i take the voltage reading when i unlock the car, the reading is between 12.24 - 12.38v, but when I wait for about 10 mins and leave the car unlocked the voltage is higher at 12.58v. Bearing in mind the battery is brand new, does this sound like the battery is ok or do you think its been depleted? I've read a new fully charged AGM battery should be closer to 12.8 - 13v. Anyway, now I've disconnected the tracker and I'm gonna give the battery a charge until its full and and see how much it depletes.

 

The fact that the battery is new is in a sense irrelevant to the problem - why? because new batteries are almost NEVER fully charged, and your battery likely has never reached full charge. The tracker is suspect, yes, and should be disconnected, but you need to get the battery to full charge - the best way to assure a full charge always is to use a good battery minder whn the car is not in use (the favoured brand being CTEK, but there are others as well). The message to start the engine is a clear signal that the battery is depleted. In normal use this message should never be seen.

 

I have put it on charge so hopefully it will be topped up to 100%. I can't use a battery tender as i don't have a garage, just a driveway. Plus I don't think I should have to be manually charging a car regularly as I've never had to with any of my previous cars, I just want it to last a few weeks without going flat. What do you think about the voltages in my previous post, does this seem normal to you?

Thanks

 

The car goes to sleep after about 10 minutes (assuming an OBD2 device hasn’t stopped it from sleeping), so the drop in current probably explains the voltage jump.

SOV’s suggestion is to fully charge the battery once, then see how it behaves. You should not have to leave it connected to a battery tender, I only do that when storing it for the winter.

In the earlier days of the F-type (and this forum), there was similar discussion as to whether the F-type’s charging system really charged the battery to 100%, as measured voltages were a bit lower than expected.

 

These cars have a Battery Management System (BMS). The BMS control module is a small device located at the negative battery terminal, connected to the negative cable. It constantly monitors battery health and issues commands through a Gateway module to adjust charging levels as the car is running, and so on.

The BMS can cause 3 messages to appear on your screen, the one you are receiving is defined below:
Low Battery - Please start your engine is displayed on the message center if the engine is not running. This indicates that the battery has fallen below a predefined threshold. As soon as the battery is charged back above this threshold then the message will be removed or it can be manually removed by pressing 'OK'.

I bring this up because I wanted you to not to confuse the BMS with the tracker and remove the wrong thing.

From the shop manual:
The BMS (battery monitoring system) control module is located on the primary battery negative (-) terminal. The module is located on the battery post and is clamped to the post with a bolt and nut. The primary battery negative ground cable is connected to the BMS control module and is attached to a ground stud on the vehicle body. The BMS control module is connected into the vehicle wiring harness via a multiplug. The BMS control module receives a 12V power supply direct from the primary battery positive terminal. A LIN (local interconnect network) bus connection provides communication between the BMS control module and the ECM for control and monitoring of the primary battery current drain and state of charge. The BMS control module measures battery current and voltage, which it communicates to ECM.

The BMS control module is able to generate DTC (diagnostic trouble code)'s to help diagnose primary battery or generator power supply issues. These DTC's can be read using the Jaguar approved diagnostic system. The Jaguar approved diagnostic system can also be used to implement a primary battery and generator self test routine. For additional information, refer to the Diagnosis and Testing section of the workshop manual. If a fault is detected, the GWM (gateway module) will override the BMS control module. The BMS control module DTC's can be used to help diagnose battery or generator power supply faults. The DTC's are stored in GWM. The Jaguar approved diagnostic system has a process for an automated power supply diagnostic procedure. The procedure provides a menu driven process to locate a fault in a logical sequence. The procedure uses the capability of the BMS control module and generator LIN bus controlled functions to provide current flow information and will detect if the BMS control module or generator are functioning correctly.

 

Hi All,

Further update: Removed gps tracker and fully charged battery. Battery finished charging at 11am and was measuring 12.95v. Just checked battery now at 10pm and it's at 12.93v, so it appears the battery drain has stopped So in conclusion, I think my issue was due to a combination of a bad battery PLUS a parasitic drain caused by a GPS tracker. I'm so pleased this seems to have resolved the issue and I'm looking forward to fully enjoying my lovely car. Thanks to all in this thread for your advice and comments.