I think my battery may need to be replaced. I'll need to remove the battery to determine if it is the original. The manufacture dale is on the back. Nothing on the front or top has a date. It's an interstate battery. With bob's ADU my volts reading is always 12.3-12.8 rarely goes over 12.9. My car is always on an intelligent battery maintainer with a health meter. The health meter reads good. The only time the health meter showed any indication of a battery problem was when I left my ELM327 dongle plugged in before I got the ADU from Bob including a different OBD2 dongle. With the new OBD2 dongle left plugged in the battery maintainer always shows a healthy battery. Should my XKR display a higher voltage rating? I searched the forum but could not find my answer.

 

Others may disagree, but I wouldn't leave anything plugged into the OBDII port.

I left my ELM327 plugged into the OBDII port on my 2013 XJ and the next day my dashboard lit up like a Christmas tree with error messages. I called my dealer service adviser and he told me it was because I left my ELM327 dongle plugged in and that I should unplug it. I did, and it never happened again. I use it together with an ancient HTC Droid Incredible smartphone and the free Torque app to monitor water temperature and voltage.

https://www.jaguarforums.com/forum/x...peared-178613/

 

What's the date on the back?

 

Mine reads 12.9-13.5 dependant, the higher end if electrics switched off (lights,blower, heated seats/wheel, stereo)

With your car being the same as mine I'd have expected similar readings.

DGL, as you may remember my car was the first in the world (apart from Bobs) to have an ADU fitted, the OBD dongle has never been disconnected since it arrived 2(?) months ago

The fact that it has an interstate battery indicates it's had a change in its 6+yrs so it should be OK

What you haven't stated is:

1) The spec of the battery
2) whether lead/acid or AGM
3) What 'intelligent' charger you're using

DGL help us to help you, as a veteran member for almost 8 years you should know better than to miss out important info

 

1. The car is equipped with an Interstate MTP 48/H8 non-AGM battery. The dealer tells me Jaguars in Canada are originally equipped with Interstate batteries. I have not disconnected the battery to remove it to confirm the age. The car is operating perfect with no problems and I don't want to remove the battery just to check the date. However, I'll do it during the winter when the car is stored.
2. non-AGM
3. I use an Optimate 6: https://optimate1.com/om6/

 

Engine on or off? 12.3V to 12.7V is correct for not running engine/alternator. With the alternator providing the charge, voltage 13V-14.5V is expected depending on the state of charge of the battery.

 

Engine on and driving, and battery fully charged after complete battery maintainer cycle. What does a low and high voltage reading indicate when driving or not driving?

 

While I do not 100% know about batteries shipped to Canada, virtually every automotive battery in the States has a date sticker on one of the short sides of the battery case. I'd be very surprised if yours did not have this sticker. The point being, one can remove the trim cover and see that sticker. I just did that inspection this past weekend, as I wanted to know what the date of the battery is and now I know my battery is dated 04/18. There's no reason to have to completely remove the battery.

 

Some Interstate Batteries use the alphabet to determine the month and a single digit number for the year. For example I just replaced a MT series AGM with a date code of F7 which was 06/2017 with a new one marked J0 for 10/2020

 

Engine on and driving, volts should read about 14.2 consistently. May drop as low as 13.8 but that's about it.

Easiest way to compare is to load torque pro to your phone and compare the display to torque pro. They should read exactly the same. If 12.3 were accurate, your battery would be drained.

 

Respectfully disagree. Anything less than 12.6 resting voltage is a bad battery.

 

Or a not fully charged battery. Can often be the case if the car is used for short runs. As long as it gets back to 12.6+V on charging and reads good on a condition test, it should be OK.

 

Yes Sean is correct. Last week I had to replace a 3 year old AGM from Interstate. Car would not start and battery was flat after a drive. Placed on overnight charge and voltage measured ok (12.6-12.9) for a couple of days and then suddenly would not go above 12.4 volts even with CTEK in place. New battery solved that problem.

 

Not driving, the voltage of a good battery is a direct indication of charge level. I find mine is usable down to about 12.2V. At that point, I really should plug it in to be charged.

When running, the voltage is an indication of what the alternator is doing. At the high end, it gets the charging process going and generally drops of as the battery "fills", settling to a float voltage of around 13.5V.

Now the 5.0 litre cars have that BMS thingy. This sometimes disconnects charging to drop the charge level of the battery before bringing it back up. I'm not sure how it works but have seen it in action once in a while. Maybe this is what you are seeing at the moment. It is described in the workshop manual.

 

Voltage is not everything either, if the amperage/capacity of the battery is below specification and a charge makes no difference then a replacement is in order.

 

Jaguars for Canada do not use Interstate batteries as OEM equipment, nor as OEM replacements through Jaguar dealers. The original batteries are either Varta or Fiamm, both European. The mention of Interstate as the supplier is, however, partially correct because Jaguar Canada has subcontracted the obtaining and supplying of replacement batteries to Interstate - but the batteries are still from the European manufacturers, and labelled with Jaguar labels. How do I know? Because I have just gone through this (yesterday) having my Jaguar dealer install a new OEM replacement AGM battery in my F-Type; the original battery was Fiamm-labelled (and still fine, but at 5 years of service, it was time).
oh...and the new battery was fully charged immediately before installation, and now contentedly monitored by a CTEK unit, reading fully charged.

 

That explains why my Jaguar dealer said their batteries are Interstate. Consequently, because my battery doesn't display a Jaguar label it must have been replaced.

 

DGL, I think you check the resting rate of the battery first and second, confirm the ADU is reading out properly. You can do this by loading a free version of torque pro and compare the results. You don't ned to disconnect the ADU I don't think. Just confirm it's not a bug in the ADU.

 

Good question, Sean. Already done. I used torque pro before the ADU. Both the same. Could this be because my battery is always maintained in top notch condition and the alternator has little work to do? I'll monitor the voltage during heavy electrical usage to see how it behaves.

 

I have had something connected to my ODB port continously since I bought my car in June 2019. No problems. Now what I have experienced in other cars, is that the voltage being reported from the ODB port is not the same as the voltage at the battery. Have you actually used a multimeter to check at the battery, and compared readings? In my Porsche Cayenne, my ODB reader voltage is off. At idle the battery is reading around 13.5VDC with a multimeter, but only reading around 12.5VDC on the ODB reader. The gauge on the dash matches the ODB reader, so obviously it gets its reading from the same place as the ODB port. I came to the conclusion that 3 different multimeters from 2 different manufacturers have to be the correct voltage reading. My ODB reader allows me to offset my readings, so I changed it to read 5% higher than what is reported at the ODB port. The only thing I haven't been able to do, is check the actual battery voltage while I am driving(for obvious reasons).