Morning everyone,I'm new here and not particularly technical so apologies for that. I bought my Jaguar XF Sportsbrake (2018, petrol) back in April and being my first Jag I must say I do love it. However I have a small issue with the 'Low Battery. Start Engine' warning light that comes up on the dash center screen, most of the time. That being said the car always starts first time, for which I am thankful. Upon reading lots of posts regarding this issue I am still a little confused. Some say this is a common fault on jags but not to worry. Others say it's the BMS (battery monitoring system) and others say other things and I don't know. Strange this just started after the warranty ran out. I have taken the car to a Jag specialist who fully charged the battery and then when he came to move it the warning came up again and he said he checked the battery and it was still holding the charge and this must be a fault with system. I mean how do I actually tell when the battery is failing with this fault? Can anyone shed any light on this for me? Also I believe this vehicle has two batteries? Yes, I've still not checked as always busy but am I right thinking the small battery is for electrics when in start/stop mode and the bigger battery handles everything else? I generally turn off start/stop as a rule. If the above is correct, is it possible to put a bigger mh battery on the car to deal with the excessive amount of power it draws, not that I'm complaining lolMany thanks,Badger

 

Welcome to the forums Badger2021,

Good to have you with us.

The average life of the battery on a modern Jaguar is around five years. Vehicle use and battery care regime play a part in either shortening ot lengthening this. The warning light is there as a reminder to run the enginje if high drain items such as a/c or audio are being used. The warning should go out when the engine is running. If it doesn't, you have a problem. However, invest in a CTEK battery maintainer and your problems will very likely disappear.

Follow this link https://www.jaguarforums.com/forum/xf-x260-99/ to the X260 forum for help, advice and information. The 'HOW TO' thread at the top is a good place to start for information on regular issues. You can also use the UK & Eire Region forum by following this link https://www.jaguarforums.com/forum/uk-eire-68/ to find other members in your region.

Please read the guidance for new members ( https://www.jaguarforums.com/forum/n...ned-up-241802/ ) which answers many of the most frequent questions about getting started.

Enjoy the forums.

Graham

 

Hello, Badger,
Congratulations on your First Jaguar!
Welcome to the forums from ElinorB.
(';')

 

Welcome aboard.

 

Welcome to Jaguar Forums Badger,

Good to have you with us.
Enjoy the forum.

If you haven't done so already you should add your car details to your signature to help others to help you.
If you need help with getting around and using the forum follow this link for some help Forum Help

 

Welcome to the forums.

 

Welcome to the Forums.

 

Hi Graham,
Thanks for the reply and welcome.
I was looking at getting the ctek mxs 5. Just need to get an outside plug socket wired in as I cannot get the car in the garage. Is this the best one?

Is it possible, or worth looking to get a higher mh battery if and when I need to change it?
Thanks again.

 

I'm using MXS 5.0 which is suitable for all current/recent Jaguar petrol or diesel models and most other members who have purchased in recent times have gone for this one.

No problem going with a higher rated battery provided it is vented and physically the same dimensions. Unless you have a preferred supplier, have a look at Tayna Batteries website. My last two have come from them.

Remember, even if a battery is supplied 'charged' it needs an overnight trickle charge to bring it up to full charge. There's a detailed procedure in the Workshop Manual for matching the BMS (Battery Monitoring System) to a new battery but I've never had any problems with a direct change.You will lose 'learned' settings and will have to reset windows and possibly audio preferences.

Graham

 

welcome to the forum - enjoy!!!

 

In my xf sportsbrake, thought I may have two batteries but only see the one, so that solves one question from my previous thread. Is there a reason I only have one?

When connecting my ctek charger I assume I use positive terminal and the negative on the body from the grey cable (see picture) and can you also charge from the box in engine bay, or is that just to jump start my car, or someone else's?

One more thing guys and gals, if I run the cable though the back window, can I still lock and alarm the car? Thanks again all
Badger

 

1. I think two batteries were only used on earlier years.

2. YES to terminals as described. However, I use the ones in the engine bay on my F-PACE just because it's more convenient.

3. With my XK wired as you propose for your XF, I close the tailgate on an extension CTEK cable and set the vehicle alarm.

Graham

 

Thanks Graham,
You're a diamond 👍

 

I know that on the XF the stop/start system first came in for MY 2012 and it used two batteries then in 2015 or 2016 it changed to one battery, and I believe the XJ was the same. My 2014 F-Type MY 2015 had two batteries and the F-Type definitely changed to one battery for the 2016 MY.
So odds on a 2018 XJ would have one battery only.