www.jec.org.uk

I will shortly be going away for 15 days when I will need to leave my recently acquired 2010 XF 3.0 Diesel parked and I am wondering how long I might expect the battery to cope with the discharges; the battery is clearly labelled as a Varta supplied to the RAC, but I have no record of how old it is. Even presuming the battery is in good order, this leads me to have a number of questions:

- How long might I reasonably expect a leave a battery in good condition before the battery drain is such that the car won't start?
- Is there anything I should do [or things not to do] to ensure that battery drain is minimised while the car is parked?
- Are there any risks to the electrics if the car is jump started, and/or if a voltage drop test is carried out with the battery in situ, what precautions should be taken to avoid any damage?
- When I go away for longer, sometimes up to 12 weeks, is it OK to leave the battery on a CTEK charger, and while a CTEK 5.0 MSX is obviously the current 'go to' for this, should a [now obsolete] CTEK MSX 3.6 [rated for maintenance charging for batteries up to 120Ah for maintenance] be OK for the job?

Thanks in advance for any info/help guidance on about these battery management questions.

15 days should not be an issue assuming the battery is in good condition. Ensure the car is fully locked as this will shut down most electric systems. Any trickle charge is fine to use for longer periods yes. I am not sure about risks of jump starting etc, hopefully someone else will know.

Hi Eddie, I generally recommend changing the battery in these cars at 5-years old, but since you are unsure of the actual age of your battery you will just need to keep a good eye on what's happening. An early tell-tale of the battery being past its best is to start having a series of spurious warning lights, especially ABS failures.
Your plan for a 15 day break should not present too much of an issue, but DO ensure you double lock the car before leaving it to stand, i.e. click the fob twice and you should be rewarded with a clunk and a beep to advise it is double locked. This will shut down most of the drain and should be fine to restart after your absence.
The C-TEK should be okay, but you might want to think about investing in an upgrade in the future, especially if the longer periods of absence become more regular once more.
Be extremely careful for jump starting as the video module is very prone to failure with voltage spikes. If you can avoid jump start, do. If it has to be given assistance, then use a battery boost box as opposed to a physical jump start - the breakdown services would generally have a boost box these days.
Hope this helps, have a good trip.
Jim

Thanks for the excellent information and advice @JimMann and @andypryce. I think I'll get my local tyre and battery people to do a volt drop test on the battery to see what sort of condition it's in. I hadn't appreciated that the risk is far less from a battery boost box than from a jump start [or that there is such a clear distinction between the two] Having run the two cars I have now for 14 and 20 years respectively, and knowing where I am with them, it's not something I've needed to be familiar with; but I realise I'm dealing with a different animal now and while it has Jaguar history that's not the same as knowing the car - but I getting there with thanks to your help.

P.S. I'm used to a 'Like' or 'Thanks' button on other forums I've used - unless I'm missing something I don't think there's one here?