I'm installing my new battery this morning and as soon as I put the cable on the posts the alarm starts going off. What am I missing???

Thanks!

 

Nothing. Just turn it off with fob or key in ignition.

 

Bingo... thank you!!

 

VEHICLE DETAILS

Your forum profile only shows 1996 VdP but you have posted in X150 forum. Additional vehicle, replacement vehicle or wrong forum?

Graham

 

So I bought the car almost 2 months ago and am absolutely in love with it. I actually look forward to going to work on the days that I take it.
It's a 1 owner 2008 XK that had 35K miles.

- the glove box broke about the 3rd time I opened it and I fixed it using the cotter pin method thanks to this forum.

-the head unit would freeze every once in a blue moon and I read on here that it was a symptom of the battery. I purchased a ctek 4.3 and I plugged it in every time I parked it. Even though the car would fire right up I noticed it would take a bit for the head unit to go from the leaper screen to the home screen. I ran the "recond" mode on the ctek and the first time I started it up the home screen popped up immediately and I thought great, however, it went back to a slow response on the next start up even though it was always on the ctek.
So. to make a long story longer... I just bit the bullet and purchased a new battery (Interstate MTP-49/H8). I went with the same wet battery that was in there since it will be on the ctek. The home screen now pops up immediately upon start up every time so I'm assuming the battery was on it's way out.
Here's the question, this is not a cheap battery at $230 with a core. What I discovered when I took the old one out is that the sticker on it says 2/18 (but the code on the battery indicates mfg date of 7/17) so I'm assuming the PO didn't use a maintainer because looking at the carfax she only put a couple hundred miles on the car since the battery purchase (2/8).
Should this battery be on it's way out and not salvageable after this much time? I purchased the new one at an interstate distributor/warehouse, do you think it's worth asking if they would prorate the price when returning the old one?

 

I also have a 2008 XK low mileage car, bought 2 years ago with 23K miles on it, and have the occasional head unit issues. I also changed the battery (which was probably perfectly fine). After changing the battery, I still have the occasional head unit issues. I find that if I hold the start button down longer, I seem to have fewer head unit issues. Also, when the head unit does not boot up, restarting the car often helps, making me think it is not a battery issue, since starting again would in theory have drained the battery a little more from the first time I started the car. I just write it off to one of those quirks of this wonderful car.

I also had the glove box fail shortly after purchasing my car, and also easily fixed it thanks to advice on this forum. I also had the back window begin to separate, and used the Rhino glue and clamps to fix it. It is holding well so far. Otherwise, I have changed the brakes and the oil in my first 36K miles of ownership. And had repairs to the car after I was rear-ended. My car should pass 60,000 miles this week.

 

Thank you, that's my fear that the old battery is not actually bad and that it's just a little quirk with the head unit. However, when I restart immediately after it doesn't come on it stays Frozen but if I wait a little bit it does come back on. It also didn't pop up as fast as it does with the new battery so I guess we'll see if it lasts.

 

All of the symptoms above are signs of a battery not fully charged, whether new or not. Unless the CTEK unit indicates that the battery is fully charged, it is NOT, and you will get random electronic "issues" , touch screen performance being one of the most common, but only one of them. It can be random warning lights, windows, door locks, seats, touch screen, convertible top not functioning properly or any number of other symptoms.

A new battery not fully charged on installation, short runs, infrequent use...all guarantee sub-optimal battery voltage and that guarantees those warning signs.

We seem to have to state this on a daily basis (this is the second time today for me).

 

My 4.3 ctek would indicate fully charged after about 2 hours. Does this necessarily mean that the battery was good. When I would start the car it would take about 10 seconds for the screen to go from the leaper to the home screen. I charged my new battery at 10 amps for 3 hours before I installed it this morning and as soon as I fired it up the home screen was on.

 

I just had my 5 year old battery replaced by the dealer 2 weeks ago. I had them check my old battery and it tested at 75% max capacity and could not be charged any further. The also tested the new battery before installation and it was at 100% capacity. I was only seeing a brightness difference on my screen but other then that no other problems. Dull screen is gone now. Also dealer reset the BMS as well as the service required note after the oil change. I also use a Ctek after every ride.

 

Thanks, that sounds like it could be a similar situation. Even though this battery is newer it might not have been kept on a maintainer while not being used over the last couple years.

 

And, if it was allowed to go flat, it will probably be ruined forever. (The battery, not the car!)