safulop

Needing a battery for my S4, I bought an Interstate of the correct size at Costco. This is a non-vented battery, it appears. Does the car require a vented battery, or have some kind of vent tube? For some reason I could not find out this information and the guy at Costco said it could be very important.

safulop

OK I guess this is stupid; it seems like a non-vented, maintenance-free battery is safe in any location. The issue would be if a battery mount was supposed to have a vent tube and you put a vented battery in there without hooking up a vent tube.

Right?

Kiwi'79

Correct I say, well that would be my logical assumption in the interests of giving you an answer.

I have not seen an S4 battery box, however my '79 has vent/drain holes that allow the passage of air, I assume yours likewise?

hlee96

Walmart sells batteries with vent tubes and they have a good warranty.

Dave928S

So called sealed batteries aren't always totally sealed, and very often have o-ring sealed screw plugs under a clip on cover, and sometimes leak small amounts as they age.

I prefer batteries with inspection plugs, which allows you to pick up early on a failing individual cell, particularly when charging, and which allow the use of a hydrometer.

Batteries with a vent tube, considering the above, and the fact we have a sealed battery box, I regard as the best option.

jcorenman

The so-called "maintenance-free" flooded (liquid-acid) batteries are the same as normal flooded batteries, except they don't have removable caps. The marketing intent is that they don't need maintenance (i.e. addition of water) during their lifetime, which of course can be cut quite short if they need water and don't get it.

Dave's point above is exactly correct: ideally you want to be able to check water level and identify a bad cell before the whole thing fails. Absent that, go for the long warranty and buy from an outfit that won't run you through the wringer when you bring it back halfway through that generous warranty period.

Most of the "maintenance-free" flooded batteries have provision for a vent tube, and some come with a vent kit. The purpose of this is to vent any acidic vapor generated during charging to a safe location (i.e. out through a vent at the bottom of the battery box).

As long as the battery box is coated with paint, undercoat or some sealer, I don't think the vent is a big deal. If there is exposed metal then it will surely corrode over time and dump your battery onto the pavement in an inopportune moment.

One failure mode for any battery is a shorted cell, turning a 12v battery into a 10v battery. The obvious problem is that it has trouble starting the car, the less-obvious problem is that an alternator putting out 13.8v-- proper charge voltage for a 12v battery-- will be grossly over-charging a 10v battery. When that happens lots of H2 and O2 (and heat) gets generated, and the vapor all goes out the vent or whatever is provided...

Truly "sealed" batteries are either gel electrolyte (which are very fussy about charge voltage), or AGM (absorbed-glass-mat), also called "starved electrolyte lead acid", which are liquid-acid batteries with the liquid absorbed into a fiberglass mat. Odyssey batteries are that type. Both are sealed with an over-pressure vent to protect them in case of a gross overcharge, but don't normally vent.

If the battery comes with a vent kit then fit it, otherwise don't worry about it. Just keep the receipt and warranty papers handy.

dr bob

If the Costco/Interstate H6 is truly an H6, it has provision for a vent tube somewhere on it. I've seen them as little short flat ports that are hidden by a plastic cap. These are often (but not always) at the end somewhat aligned with the original fill openings.

"Maintenance free" is a broad description that primarily keeps the average owner from contaminating the cells with foreign materials like tap water, or the rinse from a baking-soda bath used for de-contaminating corroded terminals. Under the top cover there are little labrynth chambers and passages that try to condense any liquid carryover from the charging process, and let it drain back into the cells. Similar to the way we like to think that our oil separators work on crankcase vapors. Still, there is hydrogen and oxygen gas evolution from the liquid electrolyte, and the chance that it includes a partial acid vapor. It has to go somewhere.

If you can't identify a port or other connection for a vent hose, make darn sure you protect any exposed metal in the battery well. That includes the hold-down bracket and the bolt for same, plus all the electrical connections at the battery posts. I coat the battery terminal connections with Vaseline after everything is clean and tight. I like Vaseline because it melts readily with normal heat, and wicks into spaces that would otherwise be exposed to the gases, like up into cable and wire insulation, and protects the otherwise-exposed metal from corrosive vapors. It also washes off easily with soap and water and doesn't stain clothing. And it's cheap insurance...

I've had vent tubes on every battery installed in the car during my stewardship period. The hold-down bolt is a pretty yellow cad plated socket-head capscrew that's still pretty and yellow. It gets a little Vaseline too both in the threaded hole it goes into, and in the head of the bolt itself. Between the hose and the protection, it's still looking original.

safulop

I just swapped the battery last night, and the old maintenance free one from 4 years ago is not vented, and nothing was corroded at all. It looks like a brand new battery with brand new posts, although it is quite dead. I also found that the battery was not held down by anything, for the past 4 years. Hmm.

So that little brassy socket-head bolt on the rearward end is really the hold-down bolt? That's good to know. I figure the shop that installed the battery should have known that too huh?

dr bob

One would think. The Group 48 now H6 battery for your car has a "lip" on the bottom front that engages a metal bracket that holds the front of the battery down. The wedge piece slides down the rear of the battery, holding it forward, and reaches down to the lip at the rear bottom of the battery to hold that end down.

Folks sometimes try and fit a more "standard" battery like a Group 24 since it will sit in the battery well. It's missing the front and rear "lips" that are needed to hold it in place correctly with the original hardware. The correct battery has the top terminals recessed in wells, and a plastic protective cover that fits over the positive post to insulate from any possible contact with the door when it's down and locked.

I'll take a look at the H-6 in the next day or two if my local Costco has one. We aren't quite the bustling metropolis that is Fresno. At least not yet.

safulop

Yes the battery I put in has the lip on the front side, it is holding the battery down on that side.

What I can't see is what's wrong on the rear of the battery. It appears that the reason my shop didn't use the hold-down bolt is that the "wedge piece" you describe seems to be missing, which leaves the hold-down bolt just dangling uselessly in its little hole there. How could a thing like that be missing? The shop had instead stuffed a protective terminal cap down the rear of the battery to hold it forward. At least they were resourceful, but never told me I was missing part of my car all these years.

Dave928S

Someone in the past has removed the rear retainer, and just forgotten, or decided not to be bothered putting it back in. If someone has just wedged it forward, they also probably didn't have a clue what was missing. It nevertheless still illustrates a shops mindset that they would not inform you that your battery was not properly secured. Here's a pic which shows the pressed metal clamping piece.