Battery acid expire?

No known expiration date, as long as it hasn't been mixed/polluted with other things in that timespan.

 

When properly sealed, acids can be stored indefinitely. However, the chances of that for your 20+ year old container is low, so I would suspect your battery acid (sulfuric acid) may be the issue.

Now, the acid doesn't "go bad" in the sense that it won't work. However, it may no longer be at the right concentration/pH to work effectively for your battery.

 

Can't speak for battery acid, but solutions can have portions precipitate out over time. That and evaporation will change the concentration of it.

 

i have the same problem, but will be buying 6 new batteries this spring, unless another solution works. how old are yours? mine are around 20 years.

 

We use the similar T-105 for power in our vacation home. The current ones are only 6-7 years old, but we've had some last as long as 20 years there.

So far you're trying what I would try.

 

You need to get the crud out of the battery plates if you hope to "revive" this cell or it'll fail again soon. There are several videos on YouTube on how to do this. You can even "re-use" your battery acid. But it looks pretty simple. Never tried it myself, but supposedly a couple guys at work have said they've done it. Worked for them or so they claimed.

 

Yes, wrong.
No, acid generally doesn't go bad.....but 20 years is a LONG time.

One does NOT rejuvenate a battery by adding fresh acid.
That cell/battery is worn out. The plates probably are shorted out due to sulfation.
It is not fixable.

 

Good point. Battery acid issues are only one source of failure. If there is any significant damage to the plates, then there is likely little you can do to regain sufficient performance.

Quick list of battery failure points are here: Why Lead Acid Batteries Fail or Suffer Reduced Performance

 

Good link.
But none of those points makes me think of a "battery acid issue".

The only three "issues" with the electrolyte (acid) are:
Loss from overcharging or being in a hot/dry environment too long.
Specific gravity change due to being totally discharged. The fix for that is charging, NOT replacing the acid.
Chemical changes due to sulfation removing some of the necessary ingredients.

Those issues are not caused by the electrolyte (acid) itself but are symptoms of it being damaged by some other action.

 

Some chargers have a mode that is intended to correct sulphation.

 

The only way the acid would be weakened is if water somehow got into it.
Since you don't know the age, or how they were treated, sulfation of the battery plates sees more likely.
Sulfation and How to Prevent it - Battery University

 

And if you really believe that.......I have some ocean front property for sale in Arizona.

 

All "acid" is not the same.
Battery acid from a discharged cell.....which is how it is shipped usually.....is a much lower specific gravity than when fully charged and has different chemical properties......somewhat.
Chances are THAT cell is not charging and will not produce much if any current.
I suspect that if you put a voltmeter on the battery it will read something around 12 volts......and the immediately drop by 2 volts if a load is applied.
Summary: A bad, discharged battery (or cell) automatically means "weak" acid.