Hi all.

Since I began using a CTEK charger, life with the XK has been great. However I wanted to get some opinions/experiences on the life expectancy of the OEM battery(or others) when using a maintainer. Also, should we replace the battery regardless of performance after a certain amount of years for peace of mind or can we rely on the maintainer to tell us when it no longer will accept a charge?

Many thanks.

 

From Battery Tender:
"This is probably the most difficult question to quantify or answer accurately! There are so many factors involved in extending the life of a battery. Weather conditions, environment, and frequency of use all play into the life of a battery. Any vehicle not used on a daily basis is a candidate for a Battery Tender charger. If the occasionally used vehicle is plugged in when not in use, the battery should last from 5 to 8 years. We have actually had customers tell us they are into their 11th and 12th year with the same battery!"

Of course if you bought a 72 month battery to begin with, you have an expectation of it lasting the full 6 years. The PO of my car used one as did I. It was the original battery so 9 years on that one.

 

I have the XK as a weekend car , once in a while a weekday putting less than 200 miles a month and being in the the Northeast where salt is used every time there is a snowflake , I'll probably put less than that all winter. I thought I wouldnt need a tender since I was still taking it out occasionally, but soon learned otherwise ... Applying the RaggTop last week , I put on 3 coats and shuffled the car in and out of the garage , starting it up atleast 8+ times going in and out. That pretty much did the battery in since it was probably pretty low to begin with. This weekend I went to turn it on to take a spin and the battery was down to around 10.8v... Had to hook it up to neighbors deltran battery tender plus. I just ordered myself one about 10 minutes ago !

Funny thing is previous owner already had it all wired up to the battery / ground for the same model tender 😀 .

So basically , yes... if you don't use the car much , the tender is a must regardless.

 

If your ultimate question is when do you know you need a new battery.

Start it 5 times in succession, then if you have a gauge that tells you how much capacity you have, if you have over 50%, you are good.

Basically a battery's capacity diminishes over time. And that is based on the number of times you have used it and to what percentage. For instance a battery has 1000 cycles if you deplete it 50% each time, whereas its 2000 cycles if you only deplete 25% each time. Which is what you are doing when you top it off with a charger, you prevent the battery from ever being depleted to 50%

 

I don't care how long my battery maintainer extends the life of the battery. I bought it because I don't drive my XKR every day and want to keep the battery fully charged to eliminate battery gremlins. Cheap insurance for peace of mind.

 

Thanks for your responses to date. Apologies if I was not clear.

The issue here is not about cost or how long the battery life will be extended. Its more about how to prevent/avoid a situation of getting stranded or having to deal with gremlins popping up unexpectedly. I have been using the CTEK nightly as I only have a short daily commute. From what I now understand is that battery life is not an exact science as there are various factors that can impact its longevity even when using a maintainer. Perhaps for peace of mind and prevention of an unfortunate situation, replacing the battery before it needs replacing eg. (yr 4 or yr 5) may be the way to go even though the battery still accepts the CTEK charge.

 

I've been getting 8 to 10 years on my classic cars with just mid-priced AC Delco batteries when kept hooked up as compared to about 3 years on a pickup truck that sits outside under a carport driven only once a week or so.

 

A good lead-acid battery will theoretically last indefinitely if kept charged. Discharge and recharge is what kills them. A battery with no load will self discharge over a period of time. Of course, our batteries have a continual load to help drain them. As the battery discharges, sulphates form on the plates and have to be put back into the sulphuric acid solution by charging. The problem arises that all of the sulphates won't go back into solution, some become stuck on the plates. Roughly, if a battery drops to 70% charge, it will regain 99% of initial capacity. If it drops to 70% again, it can recharged to 99% of that, or about 98% of initial capacity. If discharged to 50%, it will only regain about 97% of the previous capacity. Given enough cycles, the battery capacity becomes useless.

 

That's not a good practice, irrespective of the battery. Each cold start cycle and abbreviated run is likely to induce a flooded engine condition. Start it up once and let it run.

 

i know , just didn't want to leave the car running in the garage while spraying the top each time

 

Dont worry too much about it. It wont be the end of the world.
Just go have your battery tested at an auto shop. they will tell you how much capacity/life it has, if you are terribly concerned.
Keep in mind I have bought 2 batteries in row that were bad (for another car) so there is risk there too.

The most important thing you can do is, learn how to jump your car with an appropriate device, so that you are not learning it in moment of panic. There is a very specific procedure for the jags. Also learn how to get into the car/boot in event of power loss.

There is also a 9v device that is intended to save your settings when changing the battery. Buy that device now.

 

8 years, 21 days and 13 hours, 24, 25, 26......
I have seen batteries I the trunks well maintained go 8 years. I wouldn't count on that with newer models, too heavily electroniced. <<<< I know its not a word spell check, I made it up. but better than your auto fill BS

 

My dad bought a '90 Toyota pickup and sold it in '03 with the original battery still in it.

 

My better half's 08 ES 350 battery lasted about 7 years with no maintainer and virtually all short in-city driving with the exception of one 900 mile road trip. The car had about 42k miles on it when we traded it in.

 

I too have often thought about this since I installed a CTEK for the first time ever a few years ago, but before the CTEK, I never gave it much thought. I have had a lot of cars and have found that most OEM batteries, even in cars driven every day, only last 3-5 years and premium replacements usually last about 6 years, without tenders or maintainers. I am on the first replacement, installed about 5 years ago and it has been on the CTEK for most of its life as the car is rarely driven. The battery was only allowed to go flat once, while it was having some work done and sat in the shop for 30 days. It will be interesting to see how much longer it lasts.

 

I have had more than 12 years from a battery in a V12 Jaguar always kept on a battery maintainer (and one much less sophisticated than the CTEK I now use). There is no question that keeping the battery fully charged can extend the life of the battery by 3 or 4 time in addition to guaranteeing proper starting and performance. The battery in my XK (on the CTEK) is now in its 7th year.

 

Thanks for the heads up on the memory saver. I noted that most are 12v and plug into the OBDII port. Is this type acceptable or should these be avoided?

There are also some that plug into the cigarette/power socket. Will these work even though theres no power to the socket when the car is off?

Thanks!

 

if its not hot when off it wont charge the battery.
I wouldnt use the odb2 port, this may keep the car awake not to mention in the way getting in and out. I used the bolt on to the battery then just plug in the pig tail hanging out of the trunk

 

My recommendation is to replace auto batteries at four years, whether they need it or not. Jaguars seem very sensitive to battery voltage. You can push battery life much further than four years, but why? Cost savings are not that much. Alternatively, buy another battery at four years, charge it fully and keep it on the shelf until your operating battery fails.

 

Ditto. Also note that at least on my '07 the cigar lighter has a relay and is disconnected from power when the car is powered down.