Hi all,
I have a 2016 Jaguar XJ 3.0 AWD, and the car will be in storage for the next couple of months or so. I have read (at least for older models), that one should keep the charge up on the battery to avoid issues. I have a battery charger with a "trickle" or "float" setting (whichever term you prefer...), and have used that on other cars in the past with no issues. Is this just a matter of hooking up the battery charger at the trickle settings to the terminals on my battery, the same way I would on any other battery on any other car, or is there something specific that is recommended for this model? Like a lot of things with an XJ, nothing seems to be very simple when it comes to service and maintenance......
Appreciate any suggestions you can provide.

 

I am not aware of any "silly" needs on that model either.

All mine have a "Battery Minder" hard wired to the battery terminals, and are simply plugged in when stored.

The ones with the battery in the boot, have the thin "minder" wires go out through the boot seal, allowing the lid to close, so the light goes out and the car goes to sleep eventually.

The ones with the battery under the bonnet, simple as any older car, as there are no light triggers that i know of for the bonnet.

If hard wiring is not what you want/need, simply use the clips supplied. Red to +ve, etc etc.

Those things have saved me a fortune in battery purchases over the last 15 years.

 

The BEST way is undoubtedly to use a CTEK or equivalent which is correctly installed by using a ground stud and NOT directly connected to the battery negative but the method you propose should be adequate.

The reason for the recommended connection method is to avoid issues with the BMS (Battery Monitoring System) but other members have reported making direct connections without the World coming to an end.

Graham

 

Thanks for the info. I will have a look at the manual for the correct set up for now, and look at getting a CTEK minder for the long term. Appreciate the suggestions!

 

Some of the big battery chargers, especially older models, that have a trickle charge mode are really just a low amperage mode and may not ever shut off. You'd have to read the user manual to see what the function actually does. The special battery maintainers like CTEK, Battery Minder, Battery Tender, etc. are designed to monitor the state of charge, begin charging when it declines to a certain percent, bring it up to full charge, then shut itself off. The danger as I've learned the hard way with lesser expensive (tho not cheap) brands is if the circuitry fails to shut the charger off, then the battery overcharges. What you want is a smart charger that has circuitry to detect charging malfunctions and shut itself off, i.e. when it fails, it fails in the OFF position. Some of the lesser expensive models can fail in the ON position and then terrible things happen, like boiling all the water out, internal shorts, hydrogen explosions (blows the caps off the battery and scares the crap of you) or thankfully I've never had a fire. But when you've got an expensive car plugged in to an electric outlet and more so if you are sleeping in the bedroom upstairs, its not the place to try to save money.

Another thing you really don't want a "trickle" charge anyway. If the car's electronics for some reason don't fully shut off, then it can drain the battery at a rate that overwhelms the charger. Again, if the charger doesn't detect that situation and shut itself off, then it can boil the battery. With antique/classic cars like I've got, I've read suggestions of a minimum of 2 amps to cover for example if the old ignition switch doesn't fully disengage or you leave the door ajar and several interior lights stay on. Modern Jaguars could pull a lot more than 2 amps if the computers stay booted up and so you should probably have a minimum of 3 or 4 amps capacity. That way it will still cycle charging the battery each time it drops below the threshold and you can still start the car and drive it until you can get the electrical system repaired. Plus if you have one of the modern AGM type batteries, that needs a higher charging rate than traditional lead-acid types.

 

Definitely must have been "learned the hard way".

Graham