After you get it started go for a minimum of a 30 min drive without a lot of stop and goes at a fairly decent speed say around 50 to 60kph before putting the car away.

 

Why?
If it is fully charged by the Ctek I don't see the point. Leave it on the Ctek til you use your car again.

 

Update #2: went to check the charge at around 9am, so that's roughly 11 hrs of charging. I opened the trunk to check the ctek: only 4 LEDs out of 7 so far and the quick beep was still there. Fortunately it's not too loud and stops fairly quickly... I just hope it's just due to the low charge and not the sign of something truly messed up.

Haven't tried to start the engine, though. I'd rather wait for the rest of the day. I don't have to drive before tonight anyway. Glad this is Sunday!

 

Morning George , first thing you should really do is buy a 8 or 10 amp charger and a voltmeter, keep this ctek for winter use when the car is in hibernation about all it is good for , takes days to fully charge a battery .

 

Mine won't hibernate, but still, this is good advice indeed, thanks. For the voltmeter, I think actually my FM transmitter, plugged into the 12V cigarette lighter socket, gives the battery's tension...

 

If you lock the car when it is not in use the cigarette lighter gets depowered immediately.

 

Good George . Short runs will deplete the battery , buy the new charger put it on overnite battery will be Fully charged , ctek had a faulty batch a while back model ms5 I believe my mate Steve had loads of problems with his and had to replace a 3year old battery due to ctek failing to do its job . Just stick 8-10 amp charger on overnite say once a week battery will be good . Ps hope your car starts ok today

 

Based on the failure to be completely charged after 11 hours I am not optimistic that the battery is good. Also I didn't see how old the battery is so if 5 years or more I would suggest it be replaced.

 

yes. A battery can be had for the cost of 2 tanks of fuel. Or 1 nice dinner out. Get on with it and stop mucking about trying to revive a done battery. Time is money. How much time has been wasted thus far?

And as George and Cee Jay have suggested; get the new battery on a charger to ensure she’s fully charged bofore going through this situation again.

 

+1 on this. Order the battery from your auto parts store a day ahead and have them put a charge on it. They'll be happy to do it for you and most will swap it out for you at no cost too.

 

Update #3: checked the charge earlier this afternoon and the ctek was indicating a full charge, all 7 LEDs lit, including the green 7th one. Looked good. No more beeping in the end. So I decided to give it a shot. The engine started without a problem. What-a-relief!!

Now, like you guys suggested, I need to make sure about the battery, whether it needs to be changed or not. I've left the doors open for a few hours, moved the seats back and forth and had to turn the ignition on a few times as well (otherwise the seats wouldn't move). I don't know if that's enough to drain a normal XK battery or if it's the sign mine is nearing the end of its life...

Now I'm off to giving it a good cleaning outside, after taking care of the interior yesterday. Now I know I have to hook up a charger to the battery before doing so, just to be safe...

Anyway, many thanks to all of you again!

 

Hey George. There are two simple ways to test your battery. If you have a voltmeter, let the car sit overnight and off the ctek, then check the voltage in the morning at the battery posts. If it reads less than 12.6 volts, it needs to be replaced. The second and easier way (imo) is to drive to an auto parts store. They will load test it at no cost to you. Good luck and glad you got her up and running again.

 

I looked it up this morning...thanks to the FM transmitter via the 12V socket. I don't know how accurate it is, but it read 12.1V before starting the engine, which started fine.
After I arrived to the office I checked it again and then it read 11.7V, but I guess it could be linked to the fan that cools the engine off after turning it off...

 

What is an AGM?

 

At 11.7 after a ride it sounds like your battery is bad. It should read around 13.0 even with the fans running. How old is the battery???

 

I don't know for the battery. I've had the car for about 6 months now and I don't know when/if the previous owner changed it.

That being said, let me remind that it's the indication coming from my little FM transmitter, plugged into the 12V socket, therefore not measured on the battery's poles. This might make a difference, I don't know...I need to get a voltmeter, I guess.

 

that will interfere with a true/correct reading, yes.

you have a few options for multimeters. for about $80 you can have a decent one, usually 10A, 12A or 15A rated. this doesn't enable you to diagnose absolutely everything in a car, as there are sure to be some 50A circuits, but you can at least test voltages to your hearts content: these are almost all capable of 600V or higher, which covers damn near everything in and around a home. i'm not a tech nor even a thoroughly experienced DIYer, but i've done enough, and never needed nor see any occasion in the future to actually have to measure current on a circuit over 10A. buy replacement fuses in advance of needing them.

you can also get super cheap meters. they're accurate to a tenth of a volt (kinda), and if you only ever want to use it for this one specific purpose, it'll do fine. but at that point why not just get a fancy battery charger/maintainer/tester if the objective is to service only the battery?

 

How about a bad alternator? You could have just been draining a good battery for the entire trip because it wasn't getting charged.
You really need to go to a place that can do a quick check of both the battery condition AND the charging system. Any auto parts store in the US does this for free, may be the same in the Land of Lux.

 

Thought of that too...definitely the worst case scenario, but definitely worth making sure about.

 

https://www.ebay.com/itm/17459286184...oaAlyNEALw_wcB
One of these will do.