2011 XK Convertible

I had my main battery replaced at a Jaguar dealership recently. I have been going to them for several years.

After having the battery replaced, I monitored the battery voltage on a few 20-to-30 mile trips at highway speeds. I did this over a period of several days. Immediately after starting the engine the voltage would rise to 13.6 volts but only for a minute or so. Then the voltage would drop to 12.7 volts. At highway speeds the voltage would fluctuate between 12.7 and 12.9 volts. After engine shutdown the voltage usually stabilized at 12.6 volts. The car was always locked whenever it was not running. After sitting overnight, the battery voltage was usually 12.4 volts.

Knowing that sometimes new batteries aren’t always fully charged when installed, I connected a CTEK 4.3 charger to my battery for a few days. The positive lead was attached to the positive battery terminal and the negative lead was attached to a chassis ground. I had four lights illuminated on the CTEK charger within minutes and seven lights illuminated by the morning. That indicated to me that my battery was fully charged. My normal battery voltage is 12.4 volts when the car has been sitting overnight. That seems a little low to me. After engine start, the voltage would rise to 13.6 volts. That seemed reasonable, but then the voltage would drop to 12.7 volts after only a couple minutes. I thought it would stay at 13.6 volts while driving. 13.6 volts after engine start for only one or two minutes didn’t seem right to me nor did 12.7 to 12.9 volts while driving.

The Jaguar dealer said they tested my alternator before replacing my battery and that it passed the alternator test. The service manager told me that the voltages I am seeing are normal for the XK.

Am I overthinking this?

Should I be concerned about my alternator?

I welcome your comments.

 

Welcome to the forums My First Jaguar,

I know you've already found your way to the X150 forum so there's no need for a link to it from me. That is definitely the place to post your question. I keep a CTEK on mine and don't worry about it but several members with X150's have made similar voltage checks to you and will be able to advise.

Please read the guidance for new members ( https://www.jaguarforums.com/forum/n...ned-up-241802/ ) which answers many of the most frequent questions about getting started on the forum.

Enjoy the forums.

Graham

 

Welcome to Jaguar Forums My First Jaguar,

Good to have you with us.
Enjoy the forum.

If you haven't done so already you should add your car details to your signature to help others to help you.
If you need help with getting around and using the forum follow this link for some help Forum Help

 

Welcome aboard Bob.

 

Welcome to the Forums.

 

Hello.
Welcome to the forums from ElinorB.
(';')

 

welcome to the forum - enjoy