drilled holes in battery caps to refill water, how to reseal? RTV? Plastic tape?

[Warstud]

Next Time buy a Servicable Battery

 

[vavavroom]

You're a brave man. EDM rubber hole and pull plugs come in many sizes with grooves that make them snap in place and seal reasonably well.

 

[Tdbo]

And they don't seem to sell push in single caps AFAIK.

Most independent hardware stores with a decent hardware section (Ace, TV, etc) do.
Although, you could pick up one of the cheaper sets on Amazon as well, and have some for just such an emergency.

 

[spasm3]

Or drive a "nylon" (white plastic) machine screw into the hole taking advantage of plastics' give.

This.

 

[Lubener]

Simply the battery was low on water as it has been a few years of use. And bat took 1/4 gallon of DI to fill up
Now I have holes to seal. I drilled a hole and used a screw to pull out the caps.
It is a sealed battery, but all batteries, if you are aware are not sealed. water has to be added at factory.
It is a Duracell, and the caps all fit flush with top.
I think will try electric tape.

The battery likely is on its last legs anyway with that much water needed. Try using a screw to fill the holes in the caps. Tape won't work.

 

[nomas]

The nylon screw suggestion is probably the way to go .

 

[sdowney717]

The nylon screw suggestion is probably the way to go .

A good idea and can then have a pull handle.
Such as a small nylon bolt and nylon nut.
Took little effort to pull off cap with the screw.

 

[sdowney717]

Next Time buy a Servicable Battery

Sure, but I think I bought this as it was cheap at Walmart.
It's been a good battery so far.
All batteries use water.

 

[SHOZ]

Don't use nylon. Acid will destroy it in no time. Use some polypropylene or polyethylene like a milk jug plastic.

 

[andrew_j]

How old is the car it’s in?

Jb weld on cap and verify it does not get eaten. Loose acid is bad news.

 

[twouvakind]

Would a cork work? Ace, or Lowe's.

 

[CKN]

I am assuming the OP doesn't have a lot of money to come up with such a stunt. Therefore I am not going to say anything I normally would....

 

[Brad_C]

It’s not, a lot of stainless hardware is 18-8. 316 is “medical” aka highly corrosion resistant.

316 is also Marine grade and common as muck.

 

[dlundblad]

I know a guy who had a battery blow up in his face because he had a cigarette in his mouth at the time. Supposedly got the enamel off his teeth. He’s lucky he wasn’t blinded.

 

[Tdbo]

I cant believe you drilled holes... Anyway how about chopping off some plastic golf tees and shoving them in the holes?

Why chop them off?
He wanted serviceable. Keep the tees intact to give him ready access.

 

[SHOZ]

We used a special black tape from 3M on the submarine batteries. Looked just like electrical tape but the adhesive was long lasting but not as sticky as regular tape. Probably twice as thick too. No numbers on the roll so ????

Most batteries have a vent no matter what. AGMs usually are around 10 psi. Regulars though just have convoluted venting channels to condense the gas back into water but are open to atmospheric pressure.

 

[Bladecutter]

Simply the battery was low on water as it has been a few years of use. And bat took 1/4 gallon of DI to fill up
Now I have holes to seal. I drilled a hole and used a screw to pull out the caps.

You need a new battery.
And don't remove the caps from a battery that way ever again.
Just get a screwdriver under the lip of the cap, and pull up on it.

I don't understand why anyone would think that putting holes into something that contains battery acid was a proper repair path...
Right up there with good old GHT thinking.

 

[SHOZ]

Both my sealed lead acid OE Hyundai batteries had no caps to even drill into. The top is a one piece welded to the case with a vent somewhere. Both were the longest lasting car batteries I ever had at +8 years and 10 years. And still never failed but were replaced just because.

Really important to monitor the running voltage. Most cars today are much better than the old mechanical regulator days at regulating current. So too high of amperage should not be a problem driving the electrolyte to gas. Heat and evaporation are probably big issues too.

 

[sdowney717]

I tried to pry the caps, but there is no lip, top is entirely flat. And you dont know if the top is actually one piece of plastic.
All you see is a slight ring where a cap sits.
Being a liquid battery, there is no pressure in the battery, a drill is just going to make a hole, not cause acid to spray from it. The tape is still on the caps without coming loose. There is a vent free to air built into the top

 

[sdowney717]

https://www.foxxlifesciences.com/pages/nylon-chemical-compatibility
can't use nylon bolt, it would melt in the acid.

Was thinking can use HDPE such as cut a strip from an oil bottle. Put it into tiny hole, and use solder gun to melt the HDPE strip to the cap.
HDPE is a very strong plastic.

And it is easily melted into itself to form a strong plastic weld.
Can form it into a pull ring shape.

Idea is form a loop, maybe widen cap hole to a slot, and weld ring to the cap.