Vented battery a necessity or not?

Subscribe
Nov 13, 2022 | 08:09 AM
  #1  
Still getting accustommed to XJS ownership.
The previous owner fitted a new non-vented battery.
My research indicates that a vented battrey was OEM re. acid fumes and corrosion within the enclosed trunk.
However, I have read conflicting accounts on whether this is a real life issue or not, before I ditch the 2yo battery and try and find a vented one.
With annual mileage of ~5k km, I am thinking its probably not a major concern.
Any input from the forum appreciated!
Reply 0
Nov 13, 2022 | 09:32 AM
  #2  
Not a concern, say I. OEM the battery tray has a spigot on the bottom that vents out through the boot floor via a rubber pipe. As long as this is in place, all will be OK whatever battery you have.
Reply 1
Nov 13, 2022 | 09:52 AM
  #3  
Quote: Still getting accustommed to XJS ownership.
It's a special experience :-)

Quote:
The previous owner fitted a new non-vented battery.
My research indicates that a vented battrey was OEM re. acid fumes and corrosion within the enclosed trunk.
However, I have read conflicting accounts on whether this is a real life issue or not, before I ditch the 2yo battery and try and find a vented one.
With annual mileage of ~5k km, I am thinking its probably not a major concern.
If it becomes a problem it wouldn't be mileage related, IMO.

I'm a bit ambivalent on the matter. I wouldn't wring my hands. Nor be utterly nonchalant. Check on the area from time-to-time. You'll know soon enough if a problem is brewing.

Cheers
DD
Reply 1
Nov 13, 2022 | 09:56 AM
  #4  
Quote: Not a concern, say I. OEM the battery tray has a spigot on the bottom that vents out through the boot floor via a rubber pipe. As long as this is in place, all will be OK whatever battery you have.
I think that spigot is intended to drain liquid in the event of the battery leaking acid. It wouldn't vent fumes....which would rise upward from the top of the battery.

Cheers
DD
Reply 0
Nov 13, 2022 | 10:09 AM
  #5  
Quote: I think that spigot is intended to drain liquid in the event of the battery leaking acid. It wouldn't vent fumes....which would rise upward from the top of the battery.

Cheers
DD
I haven't inspected the drain hole, but would think passive venting wouldn't be that effective. My understanding was that the vented battery has a hose connected to the battery vent which exits the hole in the floor. Will have a look for any signs of acid deposition in trunk lid and will assess drainage hole condition. Agree - no need for immediate concern.
Reply 0
Nov 13, 2022 | 10:13 AM
  #6  
Quote:
Originally Posted by Mozambique
Still getting accustommed to XJS ownership.
It's a special experience :-)

Aint that the truth!
My brother in the UK tried to persuade me that an '88 XJS V12 was not the classic car any sane person would contemplate. One month into ownership and am already looking at a new clutch for currently unexplained reasons. Obvs have not relayed this joyous info to my brother to avoid his insufferable gloating
Reply 1
Nov 13, 2022 | 10:23 AM
  #7  
Quote: Quote:
Originally Posted by Mozambique
Still getting accustommed to XJS ownership.
It's a special experience :-)

Aint that the truth!
My brother in the UK tried to persuade me that an '88 XJS V12 was not the classic car any sane person would contemplate. One month into ownership and am already looking at a new clutch for currently unexplained reasons. Obvs have not relayed this joyous info to my brother to avoid his insufferable gloating
That clutch is not a Jag part, it's a GM tranny that the previous owner wore through. It's not like that couldn't be the case with any other classic car purchased used. The PO could have been really bad at driving a manual, or maybe he let someone learn on it? In any case, it's a widely used transmission that isn't made any better or worse for being installed in a Jaguar.

When electrical gremlins come out, that's when you start avoiding your brother....
Reply 0
Nov 13, 2022 | 10:48 AM
  #8  
Quote: Quote:
Originally Posted by Mozambique
Still getting accustommed to XJS ownership.
It's a special experience :-)

Aint that the truth!
My brother in the UK tried to persuade me that an '88 XJS V12 was not the classic car any sane person would contemplate. One month into ownership and am already looking at a new clutch for currently unexplained reasons. Obvs have not relayed this joyous info to my brother to avoid his insufferable gloating

You'll get a of disparaging remarks and 95% will come from a person who has never owned a Jaguar. Years ago I learned to simply counter with "Yeah, not everyone should own one" or "They're not the right choice for everyone". This type of reply can be interpreted in different ways, usually silences the naysayers, and is perfectly true

Cheers
DD
Reply 2
Nov 13, 2022 | 05:10 PM
  #9  
Quote: That clutch is not a Jag part, it's a GM tranny that the previous owner wore through. It's not like that couldn't be the case with any other classic car purchased used. The PO could have been really bad at driving a manual, or maybe he let someone learn on it? In any case, it's a widely used transmission that isn't made any better or worse for being installed in a Jaguar.

When electrical gremlins come out, that's when you start avoiding your brother....
Actually, the clutch only has 10k km on it, so while I anticipated having to spend $$ even on what is a very well sorted car, I was not anticipating having to spend any money on the clutch any time soon. The fact that the clutch issue managed to not reveal itself during test drive and pre-purchase inspection, but showed itself a week later remains a bit of a sore point.........ho hum.

It was funny actually. My brother is car mad, has the $$ but as a retired accountant has always been far too logical in his car buying (IMO). He seemed uninterested in my V12 buying anecdotes which I questioned him on. Turns out he was interested, but was trying to not encourage me.
Reply 0
Nov 13, 2022 | 11:35 PM
  #10  
Your 5 speed manual box in your V12 is not a factory item. This has been fitted in the aftermarket. 10,000 miles indicates that you have a problem in the way this aftermarket gearbox has been installed. You must find out the cause of this premature clutch failure, as just changing the clutch wil not fix the problem.
Reply 0
Nov 14, 2022 | 05:17 AM
  #11  
Quote: Still getting accustommed to XJS ownership.
The previous owner fitted a new non-vented battery.
My research indicates that a vented battrey was OEM re. acid fumes and corrosion within the enclosed trunk.
However, I have read conflicting accounts on whether this is a real life issue or not, before I ditch the 2yo battery and try and find a vented one.
With annual mileage of ~5k km, I am thinking its probably not a major concern.
Any input from the forum appreciated!
It also depends on how often you drive it. I leave mine parked for up to a month, so didn’t want to risk it. I put a red topped Optima in mine and have been very happy I did.
Reply 0
Nov 14, 2022 | 07:07 AM
  #12  
Quote: Your 5 speed manual box in your V12 is not a factory item. This has been fitted in the aftermarket. 10,000 miles indicates that you have a problem in the way this aftermarket gearbox has been installed. You must find out the cause of this premature clutch failure, as just changing the clutch wil not fix the problem.
Yes, I am well aware the 5spd is not OEM, and yes, replacing the clutch without identifying the root cause of the premature failure will not resolve the issue. Its due to go in for my mechanic to address this issue shortly.
Reply 0
Nov 14, 2022 | 04:21 PM
  #13  
The battery in my car does not have a remote vent. It is not an issue so far. Theoretically it is a potential problem but I have owned several cars with a trunk mounted battery. None had a remote vent. I never had any issues.
Reply 0
Nov 14, 2022 | 05:56 PM
  #14  
Thanks - good to know.
Interestingly just changed the battery on my Land Rover LR4 and it is vented with a hose that attaches to it. Had forgotten that. It's located under the hood not in an enclosed trunk.
Reply 0
Nov 14, 2022 | 09:52 PM
  #15  
Yes, you need a vent tube for any battery in a confined space.

There are some scenarios where a defective or over charged battery can vent enough hydrogen gas so that it collect in a confined space like a trunk a explode. Here's one scenario, Alternator goes deflective, 16volts or so and overcharges battery where hydrogen gas is rapidly produced. Then a trunk area relay is activated, causing a small spark and BOOM!!! There are many relays and sources of ignition in the boot of an XJS. This one might be a stretch but the next scenario actually happened. Battery left on battery tender, over charges, and explodes on start attempt. The tender boiled the battery, hydrogen was produces and the spark came from current arching across exposed plates inside the battery. Guess what... battery tube was not hooked up, explosion was enough to blow out rear 1/4 panel.

All that said it's just a good idea to vent the battery becasue as it charges normally it produces gases that contain some Sulphuric acid mist that can impact the condition of any item left in the trunk, including personal items and some of the vehicles sensitive electrical components.
Reply 0
Nov 15, 2022 | 01:23 PM
  #16  
id be more concerned about gas fumes in the trunk then anything from the battery. I have a Red top as well.
Reply 0
Subscribe
Currently Active Users (1)