S-Type car vs. AGM type batteries

(RCielec) #1

Hello, All.
Re: 2002 S-Type, 4.0L V-8.
I regret being so clueless on this matter; and, I apologise to the Forum for having to present this problem here.
I have need of factual, sound information based in knowledge and experience from the members of the Forum. Presently, I am overwhelmed by a confused swarm of conflicting, opinionated advice from auto mechanics, parts counter personnel and arm-chair experts.
Will the 2002 S-Type, 4.0L V-8 perform as intended with an AGM type battery ?
Will AGM type batteries throw faults/fault codes in the 2002 S-Type 4.0L, V-8 ?
Will the 2002 S-Type, 4.0L V-8 charging circuit damage an AGM type battery ?
Does anyone have any Jaguar documentation (bulletins and such ?) specifically addressing AGM type batteries ?
If AGM is truly the improved and earth-friendly technology then, sure, I’ll get on-board but, not if it is not right for the car.
I’ve read that Jaguar have instructed dealers to replace like-for-like but, that could be for business reasons not technological reasons.
Thanks, all.
R. Cielec
Greater Chicago Metro

(bdragon) #2

I don’t think an AGM battery would pose any sort of problem for an S-type, as long as it’s the right size and capacity. I’ve used AGM batteries in various Jags of this era (though not an S-type, but an XJR, etc.) and never had a problem.

Whether it’s necessary is another matter. For an automotive application, the primary advantage will be that it can stand deep discharges better, with less damage. So if your car sits for long periods of time without being used or connected to a battery maintainer, a AGM battery can last longer, being able to withstand more discharge cycles than a conventional submerged plate battery.

The other possible benefit would be that they don’t require venting, so if you can’t get a conventional battery with a vent tube that connects to the stock location, then you can use an AGM battery instead since these do not normally vent acidic fumes when charging. But since the S-type has a vent tube, just get the right battery with a venting outlet.

Other factors such as being able to operate inverted, etc. shouldn’t be an issue for 99.999% of drivers!

Considering the rather high cost of AGM batteries vs. conventional maintenance free units, I don’t think they’re worth it, unless you leave your car unused and uncharged for long periods of time.


(RCielec) #3

Hello, Dave.
I apologize for the delayed response. Work has unexpectedly expanded at both ends of the clock.
Thank you for the information.

Yes, this recently acquired car may sit unused/spotty use until I go through it…

Additional questions I may ask you are truly for me to learn not bicker. So, apology in advance if I may unintentionally sound confrontational.
In context of the 2002 S-type & Jaguars of that era…

What about a car’s charging system ? Since the cars were spec’d with submerged plate, could the car’s charging system damage an AGM ?

Thanks, again.

All the best,
Greater Chicago Metro

(bdragon) #4

I don’t think that there would be any problem with the charging system, especially on a modern car (one built in the last 20 years.) Any issues that might have occurred with AGM batteries and car charging were with systems that undercharged AGM batteries (because these charge at a somewhat higher voltage than submerged lead-acid types.) If AGM batteries didn’t work for the vast majority of cars, these batteries would have little market (especially the ones made in automotive sizes.)

Still, if the car is to be stored, it is still best to keep it on a charger or at least put a disconnect to cut the battery off from continuous drain. Even though an AGM can take deep discharges better than normal batteries, they still lose life each time they’re totally drained. And they are really expensive to sacrifice in this way.

Though a disconnect means all the electronic items need to be reset, if the battery discharges from non-use they all have to be reset anyway. And particular to the X200 S-type - they seem to be very sensitive to low battery voltage and weakened batteries. It seems that all kinds of random engine trouble codes and malfunctions can stem from a weak battery, so it pays to keep yours in top condition.