Hey folks - been a while as my baby has been purring along pretty darn good. However, the other day while driving I looked at my dash and saw the battery light on. I am thinking "wow, I have only had this battery since 4/2021 - how could this be possible?" I usually get a full 3 years out of my batteries. It was a Costco battery I bought in California and now I live nowhere near one to even get a warranty on it...btw.

Anyhow, after the next start - no light. Went days without seeing the light and I thought maybe it was because I hardly drive and it had sit for 3-4 days. (NOTE: I live in North Dakota so this battery has gone through 2 pretty long, cold winters!!!)

Then the other day, while out of town the light comes on again. Once again, when I turned the car off and turned it back on the light was gone and the car is running fine. I can usually tell when my battery is going as I will start hearing solenoid's doing weird things or my trip speedometer will reset - you know - the regular things.

So - I took the volt meter to it. The reading with nothing running was 12.4V which is technically 0.2 below where it should be at 12.6V - then I started the car and naturally I could not see the voltmeter to see if it dropped below 10V to see if the CCA were at a proper point....but when I came around and looked while the car was running I was at 14.8V so i know my alternator is working and when i turned on my headlights it dropped to 13.7V which should be just about right. So...now I am puzzled....

I decided to go to NAPA and have them run a battery test with a print out. They did and it came back that my battery passed all the testing. However I don't know if the guy set the machine properly or what but on the printout it seems the CCA are low to me as for what a JAG battery requires. I thought our batteries needed a minimum of 765 CCA and a 140 RC? If this is correct, my CCA on the readout were at 726. I will attach a photo.

So my question is, by all the information I have provided...is my battery lacking in CCA or might I have a battery cable going bad that is causing the intermediate light coming on?

Thoughts and suggestions are welcome!!!

BTW: Ignore the test date - it was not set on the machine. The test date was today: 08/03/2023

peace out,
daddylogan

 

The battery cables can become corroded under the insulation (where you can't see it).
Common issue with our cars.
Best suggestion.........check and replace the positive and negative battery leads with suitable aftermarket ones and see if your symptoms disappear.

 

BTW....what is the recommended battery for our Jag's? I think it was 765 CCA and a 140 RC? Could someone verify for me...or the BEST specs ;-)

peace out,
daddylogan

 

daddylogan, I would say to try this. Let the car get cold overnight. Open the hood of the car and then get into it. start the engine and then turn on the following: Both seat heaters, headlights, dash fan on high (set to heat preferably, but A/C works), and rear defroster. This will put a fair load on the alternator. Let it sit like this for say 5-10 minutes. At this point, turn the engine off and go back to the batttery. Cup your hands OVER!!!!! the battery terminals and see if they are hotter than the surrounding metal. Notice I said over the terminals. They can get extremely hot and are good for frying an egg. If you feel that the cable is warmer than the surrounding metal, replace the cable.

Something else that you can do is use a multimeter as you are letting the 5 minutes go by and put it across the battery (on the lead posts, do not touch the clamps). Are you getting something above 12.6 VDC? You can then also open up the fuse box and touch the top of any fuse (there are little silver openings on top of each fuse) and you can measure the voltage between there and the chassis. If you are getting more than say a 0.2 VDC difference between the battery voltage and the fuse voltage, then you are kinda confirming a bad battery cable.

Per the service manual for the X-Type, it says that the gas engines should have a minimum of 680 CCA battery. Me personally, I say get the biggest battery that you can fit in the tray. More CCA is not going ot hurt the car.

 

See my thread AGM battery

 

i agree on battery cables. to determine which on, run the car till the light comes on if possible. pop hood and take a temp gauge and get a reading of both battery terminals. The hotter of the two is your bad cable. The difference on my car was under hood and positive cable 135 degrees, and the negative was i believe 202 degrees. while replacing the neg cable i also added a cable from the engine to the chassis.