Battery acid tester?

[supton]

Ran into Walmart the other day to get a battery, and spied this:


I don't think that was the exact one, but it said to suck up battery acid, then flip over and read the battery charge state. It would then indicate how charged the battery was. Seemed kinda like a coolant specific gravity tester, but for battery acid.

Wouldn't I get that info from simply using a voltmeter and ambient temperature?

I suppose this could pinpoint which cell may be weak, though; but since a weak cell can't be fixed, any weak battery would just be replaced...

 

[Chris142]

Its a hydrometer. Dont see many today but they were popular 50 years ago.

 

[old1]

Yes, it is a hydrometer, and I use one all the time for checking state of charge of batteries. Voltage doesn't tell the whole story. But you don't suck up the electrolite and tip it up. You hold it upright and see how many balls are floating.

 

[supton]

Originally Posted By: old1
Yes, it is a hydrometer, and I use one all the time for checking state of charge of batteries. Voltage doesn't tell the whole story. But you don't suck up the electrolite and tip it up. You hold it upright and see how many balls are floating.


The one I saw said to tip it up; all the text was upside down too.

 

[totegoat]

I use a voltmeter on the 8 batteries I own. A battery filler is best for adding distilled water as needed.

 

[circuitsmith]

I use this hygrometer. Has a graduated scale and built in thermometer for temp compensation:

https://www.amazon.com/gp/product/B0050SFVHO

 

[punisher]

Here you go.

https://www.amazon.com/Robinair-75240-Co...=coolant+tester

 

[SHOZ]

The cheap one with the floating balls are good enough. Just what are you going to do if it reads low and is fully charged?

 

[circuitsmith]

Originally Posted By: SHOZ
Just what are you going to do if it reads low and is fully charged?


Shop for a new battery, the current one is sulfated.

 

[SHOZ]

Originally Posted By: circuitsmith
Originally Posted By: SHOZ
Just what are you going to do if it reads low and is fully charged?


Shop for a new battery, the current one is sulfated.
Well you won't be adding acid to it. Usually people add water and then the acid mist out or leaks past the post so if you have acid on the top of the battery everytime you add water it gets weaker.

 

[circuitsmith]

My last battery never needed water in its 9 year life.
If it had a battery that leaked enough acid to lower the levels I'd replace it anyway.