I am on my second battery since new, I believe I replaced the OEM in 2013. It has been a a C-Tek MUS 4.3 ever since. I've only had 2 instances of battery trouble, both were while the vehicle was out of my hands for several weeks at a time, otherwise nary a problem. Until today when I went to open the hatch and couldn't. I noticed I didn't have the C-Tek plugged in, but it's not the first time either, there have been many times it's left disconnected particularly when driving it every day, with no ill effect.

So now I kind of wonder what the point has been all of this time in having a maintainer. I the original lasted 5 years without one and other than the Infiniti I have now which has had a new battery fitted nearly once per year under warranty for the last 5 years, every other car I have ever owned has always had a battery last 5-6 years...

 

What brand and type of battery, flooded (wet cell), gel, or AGM? They have different expected longevities that are affected by operating conditions such as vibrations, maintenance and temperature. I realize that it's hard to check the battery since it's buried in the trunk. Access is difficult and you can't see the electrolyte level (wet cell) unless you take it out of the trunk.

The expected life of your battery was adversely affected by (1) the two times that your XKR was off your CTEK for several weeks, and (2) the Florida heat. Nevertheless, you got 5 years of service out of it, which really is better than most. Could it have lasted longer? Perhaps. But a CTEK can't give any battery immortality. It probably wouldn't have lasted as long as it did without the CTEK.

The secret to a long and happy life is "don't sweat the small stuff." Everything is small stuff, except your health. I know you take great pride in maintaining and modding your XKR and it returns the favor with great fun and enjoyment. Wondering about the point of having a CTEK will get you nothing but grey hair.

The road of life is short, so don't sweat the small stuff and enjoy the ride.

I have seen the end of the road. I'm still here because I've learned to not sweat the small stuff. This photo was on the wall directly in front of the treadmill where I had my nuclear stress test. I think they replaced it after I told them that it sent the wrong message.

 

Hi Stuart,

Certainly no sweating going on over here. What I was posing was perhaps due a bit of misunderstanding on my part of the purpose of the C-Tek, sure it is great to keep cars like ours fully charged when they are driven very little, I've put about 7000 miles on it in 7 years with the majority of the overall mileage in the first years of its life of course but it did nothing to make the battery last any longer than it normally would have or any longer then the original from the factory.

I have never owned a battery maintainer, though at least half of the cars I have driven have been leased so no time for the original batteries to fail, and the ones I have owned for more than 5-6 years the OEM battery also lasted as long including the OEM battery fitted to this XKR. Even all of the other Jags, including the 2008 XK vert I leased, never had battery issues.

In one of the many C-Tek threads another member mentioned that he had a C-Tek but did not have it connected the car all of the time, only when it was in storage or not being used for extended periods of time and he never mentioned any battery issues. In my case the C-Tek has probably been connected to the car for 95% or more of the time since it was fitted with the new Interstate battery by the dealer in 2013.

 

I've had a number of collector cars on various brands of maintainers and have gotten typically 8 to 10 years out of a battery. But I have had a couple of batteries go bad much quicker even tho they were "maintained". I did learn one lesson the hard way with a vintage Corvette. When shutting the car off I had to get the worn switch in just the right position, otherwise I could still remove the key but the car was still "on". The accessories were pulling more juice than the maintainer could supply. The battery didn't just go flat, but completely fried in under a week as the smart charger never shut off, trying to keep up, and boiled away the electrolyte.

I've also had a couple of these smart chargers fail on me (tho other brands, I only recently switched four to CTEK and still have a couple of Battery Tenders going.) For the most part, the Battery Tender brands would fail "off" but I had a Sears Diehard brand that failed in the full "on" position and might have been catastrophic if I hadn't caught it in time.

To have a maintained battery fail after five years doesn't sound alarming to me, rather maybe just bad luck within statistical probabilities. But what I would do after replacing the battery is monitor that CTEK closely for a full day or even two, checking that its quickly reaching a full charge, then going into maintenance mode and staying there. If it's not, then you've either got a problem with the CTEK unit OR an issue with the car itself that's still drawing too much current when its shut down. But its probably OK.

And consider that its been discussed on here before that modern Jaguars don't necessarily shut down completely until you lock the doors, rather remaining in a sort of standby mode waiting for its driver to return any moment. I haven't tested it on my XF, but just out of curiosity I put an ammeter on the old XJ8 years ago to check and sure enough, the current draw dropped considerably within moments after locking the doors. So I now make a habit of locking the Jaguars doors even in my own garage.

 

Hi Phil

Thanks for the input. Others I have spoken with about C-Teks have also indicated as much as 10 years from a battery, I was expecting at least more than the usual 5-6 years for sure.

After a drive it goes right on the C-Tek and has always taken several hours at steps 2, 3 & 4 before finally settling on step 7. No I do not always lock it but if I am not mistaken the only difference in not locking is it takes longer for everything to power down and go to sleep which with the C-Tek always connected, shouldn't make a difference.

I have not checked to see which model Interstate it is but I know it does have the vent hose connected and it was supplied and installed by the Jag dealer. Actually now that I think about it I believe it went back to Interstate as directed by the dealer and replaced for free a few months after it had been fitted.

I have seen arguments for flooded v. AGM but am leaning towards a sealed AGM Duracell Platinum with 48-month free replacement.

 

Hi Jeremy,

Hope you are doing well!

Keep an eye on those AGM batteries, I know for sure the Bosch S6 AGM is too tall to allow proper installation of the "battery Cover". After measuring against my current Bosch S4 battery the S6 AGM is 3/4" taller. Just enough for the negative battery terminal to not clear the cover properly. Yeah, you can jam it in there and barely get the retainer screws started on that side to hold it in place, that was a no-go for me and I returned it.

This also could be just a 2010-up issue because of the module on the negative cable, but keep an eye on that area of your 2008 just in case.

Cheers,

Dave

 

Well, shoot. If I have the Interstate MTP93T8 7-inch high fitted which Jag lists as the OE replacement, the AGM version is 7.5 inches tall.

 

In Louisiana, if I get more than 2-3 years out of a battery I consider that a success. The heat here really eats them up.


I replaced the one in my Jag because the screen kept getting locked up. It does with the new battery too, so that probably wasn't the issue. I think the one we pulled out of the car was original, meaning 10 years old. As far as I know, it was fine.

 

Okay just checked the battery and it is actually newer than I remembered, it’s only 4 years old and says T8-90 6-year performance warranty so I guess it’s off to Interstate for a replacement.

Car does not sit in the heat and the age of the battery makes me even more puzzled, by my statistics, with the exception of the Infiniti, the only battery I have ever had on a Ctek actually wore out faster than any other OEM I have had without using a maintainer...

 

just a thought that perhaps the c-tek setting is defective in some way and slightly overcharging the battery.

 

I'm not sure on the Ctek but I don't think you want to have the battery plugged into the chargers and not the charger to the wall for too long. Another member mentioned that a power flicker caused his Ctek to stop monitoring and killed the battery.

 

Can't find much, if any info on that battery.
Last fall I replaced the battery in my car, and when it was pulled out I saw that it was an Interstate MTP-49/H8, which had an 85 month warranty (pro-rated). And looking at the date code (7/2011) it actually hadn't reached the end, but was pretty close, so it wasn't worth pursuing, and I had already purchased the replacement.
I had it replaced it with a Bosch Platinum 49-850B AGM (group L5/49), which has a 4 year free replacement.
Bought it at Pep Boys, and took advantage of their 'free installation', which I'm sure they're reconsidering after watching them struggle for half an hour doing the replacement.
Fits perfectly under the cover.

 

Hi Dave,

Checked the specs on the Bosch batteries and they appear to be the same as the Interstate, Duracell, etc. The S4 is 7-inches high and the S6 is 7.5-inches. I don't know if the 2010+ installs differently but I don't believe it does. Are you sure it wouldn't clear the cover? Since I added the AUU module to the stack on the right side, it is now taller than the current fitted battery by about half an inch and the cover fits with no issue. It is only about $30 more for the AGM and comes with 18 more months of free replacement warranty, etc.

 

Interesting, both of those batteries show a height of 7.5 inches as well.

 

The Interstate MTP93T8 is an old-school, conventional, 12v lead-acid battery, also known as a flooded or wet-cell battery. It has six vertical lead/calcium alloy plates suspended in a liquid sulfuric acid electrolyte. Every time you start your car and while the battery is being charged It emits hydrogen gas that is explosive and becomes corrosive. Every time it vents gas (which is a lot), it loses its ability to hold a charge. If it sits too long without recharging, the battery acid eats into the lead plates ("sulfation") and eventually it won't hold a charge. That can also happen if the battery is (1) overcharged and boils out the electrolyte so that the plates aren't covered, or (2) damaged by vibration, such as hitting a pothole, and causes an internal short-circuit.

Here's an example: Interstate MTP-93 Replacement Battery - check your installation - BMW M5 Forum and M6 Forums

See also: http://www.autos.ca/auto-product-reviews/wet-or-dry/

Note that the 4.2L and 5.0L X150 have different alternators and charging profiles. That's why your Owner's Handbook says to replace your battery with the same type as original installed by the factory. All 4.2L models were fitted with conventional, flooded batteries. Sure, many Forum members have replaced their flooded batteries with a superior AGM battery. Their alternators may not be up to the task, but using a CTEK maintainer that is designed for both flooded and AGM types solves that problem.

See also: https://www.optimabatteries.com/en-u...ng-agm-battery

I suspect that jahummer's battery suffered some sort of internal damage that shortened its expected life.

 

Thank you Stuart.

The C-Tek has an automatic de-sulfination mode but it has never ever used it even when switching to the recon mode.

I haven’t hit any potholes or any other sort of jarring so I guess about the only thing I can consider is the battery has failed on its own.

Do you have an AGM in your Portfolio? Are you suggesting the charging system limitation is not relevant since I use the MUS4.3?

 

Not so. You can leave the CTEK unit plugged in for months at time (I have done this over a period of years) with no effect other than a fully charged battery. The CTEK unit is not a "charger" - it is a maintainer and that is quite different. And I have had a battery in a V12 Jaguar last longer than 12 years (using a maintainer) but modern cars require far more from a battery.

 

Their specs are WRONG, my tape measure no lie. :-) 3/4" Difference in height between the 2 batteries. 100% fact.

FWIW, my S4 is less than 2 years old and they could have changed them, but that would be weird.

I can't speak for any other batteries, but the Bosch S6 AGM is a NO GO on fitment on my 2010 and yes the listed Spec is 190mm. I don't recall the overall height, but I remember it being even taller than the listed spec of 190mm.

I tried 3-4 different times and even had Jeannie to double check me, no way was the cover going to fit properly and I was so frustrated I was afraid I was going to break my cover trying to make it work. I tried relocating the Neg terminal at a different angle and it didn't change the fact that the battery cover was jammed down on the top of the battery and the Neg Terminal. Removed the S6 for the last time and once the S4 was installed the cover went right back on perfectly with no effort as before.

Cheers,

Dave

 

I have a flooded battery in my Portfolio and don't plan to go AGM. I still use my old BatteryMINDER brand maintainer since it has continued to work just fine for over 7 years. It's not my daily driver.

When I bought my CPO 2013 XJ in 2014 I bought a CTEK MUS4.3 to use with it. My XJ has the Intelligent Stop-Start system with a primary AGM battery and smaller, secondary battery (I'm not sure if it's AGM, but it should be for what it costs!). Interestingly, I've had no problems with my primary battery but the small secondary battery died and was not covered under the CPO warranty. I guess the circuit allows my CTEK to maintain the primary battery but not the secondary. My primary battery is original and is over 6 years old and still gets the job done. I think the CTEK helps. Although it's my daily driver, my trips are usually short with little highway driving. I prefer the CTEK, as it's a newer and better design.

That's why I keep both on battery maintainers. I don't drive long enough for the alternators to keep those batteries fully charged.

Note that I'll never buy another Battery Tender brand product again. The last one I had lasted 5 months and was made in China with a plastic case that melted and almost caused a fire. My previous BT was made in the USA and had a metal case, but died after 20+ years). Worst customer service ever. Battery Tender brand products are junk - spend a little more and buy a quality CTEK MUS4.3.

 

It makes no sense to me to keep a battery until it fails. I used to do this when I was young and poor, and failure always seemed to occur at the worst time and place. Now, I replace batteries every four years - period. EZ-PZ. The $$ saved by an extra year or two of usage is mabe less than $100.
My Jaguar is a daily driver, winter and summer in OR, and trips are usually very short. Whenever, we are gone for more than 48 hrs, I put the Jag on a Battery Tender. My Battery Tenders (I have three) are "metal", and all are quite "old". One of them is has been continuously attached to a stored motorcycle for 20+ years.