Battery low and battery maintenance

Rivendell

New member
Battery low. After a service in a dealership, my battery low caption illuminated. Jaguar Assist arrived quickly and fixed it: some software had to be re-loaded that had been keeping bits of the car ‘alive’ when it was shut down (apparently it’s not uncommon after a service?).

Battery maintenance. So, kind of related, I’ve decided to buy a charger/maintainer. The CTEK MXS 5.0 gets rave reviews, but has anyone used the ABSAAR Pro 8.0 as an alternative? I’ve nothing against the CTEK, but have used ABSAAR chargers in the past and found them to be excellent. The ABSAAR is an 8A charger with a digital display and is about the same price.

Secondly, I have heard that you can close the boot and keep the battery ticking over through the winter. Instinctively this seems to either risk the charger cable, the boot waterproofing (or both) while also risking increased temperatures during charging. I’m a complete novice so have no evidence to support my ‘common sense thoughts’. If I’m leaving the car for a period where battery maintenance is a good idea, how should it best be done?

Thank you.
 
You'll find previous posts that mention dealers not disconnecting from the OBD port property, which leaves processes running and flattens the battery. I think the answer was to disconnect the battery briefly.

I have had my ctek connected through the boot seal for 4 winters,. It's flexible enough and the cable us quite thin. I don't envisage it being a problem. Loads of owners doing it, I expect we'd have heard something by now if it was.
 
Have used the CTEK for a few years now. Great bit of kit. Just keep cable loose as tailgate closes to ensure no snagging.

No issues with overheating. Highly recommended to keep sensitive batteries & electrics satisfied 👍
 
That is very interesting Rivendell. I had my car serviced last week and immediately the battery warning message came up. Phoned the dealer but they did not mention software, just suggested it might be the battery. I booked it in but could not get a date before the dealership closed due to Covid19.
Now the battery is completely flat and I cannot get in the car even with the emergency key ( my post is below yours).
I should be very grateful if you could give me any more detail you have about the issue and what causes it before I do battle with the dealership when they reopen.
Regards
 
Mike, the Jaguar Assist technician said he had attended other F types with identical issues specifically after servicing. Mine went the same way as yours – I got the caption on the day I picked the car up from the service, drove the car over quite a distance then turned off the engine without the caption illuminating. I thought I’d fixed it. When I returned to the car two days later to start it, it was flat as a dab and I needed to break in with my emergency key. The technician who attended my car said that it was software related and that he had found two different bits of software that were preventing the car from shutting down fully electrically. He didn’t mention the OBD issue, but it might be related. He reloaded both bits of software and then turned the car on and off a few times and was able to check through his laptop that the car was fully dead. The problem is now fixed. I leave my car for long periods without it being started or used (hence the query on on the charger), so I did wonder whether my battery would be a bit iffy. However the technician told me it was still in excellent condition (my car is MY 16).
 
Thanks very much Rivendell. That is very useful and I will be sure to go through this with my dealer when they eventually reopen. I had to replace the battery last year so I was very surprised when I saw the error message.
 
mickjaguar said:
You'll find previous posts that mention dealers not disconnecting from the OBD port property, which leaves processes running and flattens the battery. I think the answer was to disconnect the battery briefly.

I have had my ctek connected through the boot seal for 4 winters,. It's flexible enough and the cable us quite thin. I don't envisage it being a problem. Loads of owners doing it, I expect we'd have heard something by now if it was.

Thank you. Very helpful.
 
DaddyDarren said:
Have used the CTEK for a few years now. Great bit of kit. Just keep cable loose as tailgate closes to ensure no snagging.

No issues with overheating. Highly recommended to keep sensitive batteries & electrics satisfied 👍

Really helpful. Thanks.
 
Rivendell said:
I have heard that you can close the boot and keep the battery ticking over through the winter. Instinctively this seems to either risk the charger cable, the boot waterproofing (or both) while also risking increased temperatures during charging.

I've used a CTEK on my three previous, and now my current, Jaguars and have had no problems with charging with the boot closed. I run a mains extension lead into the boot so the CTEK is fully in the boot while charging (I have to charge outside on the drive) and haven't had any issues with clamping the 10A mains lead with the boot lid. Just make sure it clears the lock(!) and don't always use the exact same area to run it out. I take out the boot cubby and put the CTEK on the metal boot panel to assist in heat dissipation, but the charger doesn't get very hot in use.
 
Been running a CTEK for 5 years with the F now.

As most folk have the battery maintainers hooked up to the positive busbar, it is imperative that a fuse is put in the +ve side of the charging cable.

I have been close to a dead short where a metallic object in the boot sat squarely across the two terminals of the CTEK comfort plug...the rubber protector I had forgotten to re-fit.

Now, it may be a million to one chance of it actually making electrical contact, but that's a fire waiting to happen, as is shutting the cable in the boot as I do.
God knows how many times the cable is getting squidged, but to mitigate any risk, a 5 amp inline blade fuse will pop before any damage can be done.
 
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