Hi everyone.

i purchased a new battery for the convertible,a Varta 100ah , and the Ctek 10A charger + trunk plug kit.

Following the great tips @ceejay and @jahummer i also purchased an automatic battery interruptor that can disconnect the battery from a remote( whenever i park the car ) OR if the battery goes under a preset level if I forget it.
https://mota-shop.com/products/coupe-batterie-universel
My question is, as I can set the voltage level where the battery disconnect , and knowing the XK is demanding extremely high levels to stay bugproof, what level should I set up the thing?

Thanks.

 

The diagram on the advert sort of answers that question indicating 12 volts or lower's too low so I'd set it about there and experiment.

 

I think it’s higher than that. A fully charged car battery would show 12.6 volts. Anything less than 12.4 V is considered discharged.

Google “car battery voltage” or see https://www.autobatteries.com/how-ba...our-car-starts

 

Wouldn't the settings for the soft top be lost requiring a re-program of the settings?

 

Certainly they would if the battery is actually disconnected from the car. The radio settings might also be lost and the engine/gearbox management system would have to reprogram itself over the first 50 miles or so.

Personally, I don't think this is a good solution. It would be much better to simply leave the Ctek connected if the car is going to be left undriven for a month or more.

If the OP wishes to implement the battery disconnection approach, I would set it at 12.5V as going below that is already potentially shortening the battery life.

Richard

 

All this extra gadgetry and fiddling is a waste if time, effort and money.
I have none of it on any of my vehicles. Keep a proper battery in the vehicle and walk away.
To answer the original q I concur that if the battery reads 12.4 v, you are already at ~70% capacity on a lead-acid battery. One may decide to keep fiddling with it… I however am running down to the dealer for a new one.
The only problem is the decision to keep a deteriorated battery and continue fiddling with it as opposed to swapping it out when it goes.

My vehicles routinely sit for weeks if not months on end, no issues.

 

What’s been missed is a previous thread. The OP doesn’t have mains power available when the car’s parked so no way to use a Ctek all the time. He was concerned of the car sat for long periods he might find a flat battery. With the battery disconnect he can be assured the battery doesn’t face any drain issues. Radio settings do not reset. And TCU doesn’t reset. Fuel adaptations will however.

 

The thing is my car sits in a city (I live 2/3 of the year in Paris). I drive the car once a week or sometime once every 10 days. Although I'm one of the rare lucky guy to have an underground parking, there's no way I can plug the Ctek almost permanently.
That's why I've been suggested this solution. If that doesn't work I'll have to sell the car...

 

I just got a new Battery although the previous one was not bad... there's a drain in some XKs. The trouble is known by most of owners... But the problem is that the cars starts acting like a christmas tree if the battery is too low... and that can be dangerous ... Ending on the road side on the highway at 2 in the morning under the rain is not a liveable option..

 

By "reprogram the soft top" are you speaking about the 2 time window at low, 2 time at high thing?

 

Didn’t miss anything. My xkr has sat for 4 months, no issues. (In a proper Canadian winter, no less. FYI, it bottoms out at around -35C, here) If the quiescent draw is beyond what is spec’d, yes there is a fault which needs to be corrected. Granted, the MY06 is distinct in electrical behavior from 2 specific, later models.
As mine is in a locked carriage house, I don’t lock the car. Thus the alarm is not activated.
Sure, you can play the battery post switch game. And when the disconnected battery is losing capacity over time…

Employ good habits. (Turn everything off before shutting down the engine.) And I suspect you’ll get better mileage.
Apologies for the rant! How many years, threads and posts have gone by where many swear its not the battery… when it is.
I’ve lost count.

Off to play in the freezing rain with the LR4…. what fun!

 

As Guy has mentioned, a XK with a properly operating electrical system, should be fine, parked for several weeks. I parked mine, with a 5 year old battery, for seven or8 winter weeks, garaged. This would be with a double locked Jag, and it started instantly.

never have used a charger in this car.

the OP, May have some type of drain going on.

 

Yes the OP’s already discussed his battery’s issues in a previous thread. Either his previous battery had failed or he’s got something defective with the car’s electrics.

If the newly fitted battery’s been properly charged to full capacity, surely he’ll know soon enough. And I believe it’s daily driven so the generator should be able to keep the new battery maintained.

 

Hi everyone,
So, the battery was plugged on Wednesday.
Following your advices here, i decided to test it first.
Prior to installing the battery it was connected to the Ctek forthe night and showed it full (led light at level 7 on the Ctek) . Tested it was saying at 12,62V.
Surprisingly the Ctek trunk plug indicator showed Half charged only. (why?)
Closed the car with 2 press on the door handle.
I tested it today,72hr later. It showed 12,42V.
I drove the car for some shopping. 50 Km (31 miles) with 5 parking time and restart.
Being back home I checked the car 5mn after stopping the engine, it showed 12,46V.
Tonight is 1C (33F) outside.

Think I'll test it again in 48H.

What do you think?

Thanks.

 

There is something wrong with either the battery or the charger. If you put the battery on the Ctek until it shows fully charged, then disconnect the Ctek and measure the battery voltage, it should read well over 13V and probably closer to 14V. If you leave the battery for a couple of hours, off the car. and measure it again it should still be as high as 13V.

Check your meter reading against some known voltages (small new 9V dry cell or whatever)

Check the battery on several occasions when it is connected to the charger and showing full charge. It should be reading around 14V. If it is, the Ctek is fine but the battery is no good. 12.4V a couple of days after being fully charged will not be sufficient for our Jaguars.

Richard

 

Well Thanks @RichardS ,
The battery is brand new, the Ctek 10A charger too.
I'm not going to waste anymore time, and will plug the Ctek overnight in Recond mode. And I'll see..

Meanwhile, any other advice is still welcome.

Thanks.

 

Faulty products exist and it does sound like one or the other isn't working properly, so I recommend you perform the very simple tests provided to eliminate those two obvious potential issues before you go chasing ghosts.

 

Check the voltage with a meter when the CTEK is charging, you could also check the charging current from the CTEK.

 

Let me just clarify that when I said "12.4V a couple of days after being fully charged will not be sufficient for our Jaguars" refers to measuring the voltage when there is no load on the battery. If the battery is installed in the car and you measure the voltage with the boot open, then the voltage will be reduced because of the current drain caused by the car security systems, lights in the boot etc.
The only way to properly measure the accurate battery voltage once it is installed in the car is to be able to see the voltage display when all the doors are shut and the security system is in its full resting mode. The current drain is then less than 30mA (or it should be .... you can measure this to check that there is nothing excessively draining the battery) and the voltage drop is negligible.
There are various methods of measuring voltage and current when the battery is connected. You can find these on the web or come back here as many of us can provide further details.

Richard

 

Hi,

So I just went to check the car.
Opened the trunk (so yes, the trunk lights were on, but didn't open the car so all was still closed)
I checked the voltage with the charger ( which was at stage 7)still plugged and it showed 13,46V on the battery terminals.
I unplugged the Ctek and waiting 1mn and it showed 12,86V.

Does it sound right to you ?
Should I perform anything else ti check the battery ?

thanks.