does anyone on here use them or atleast know how to use them? they can tell you alot about you battery.

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have no worries.....President Obama swears "If you like your gun, you can keep it

A dying art since most batteries are sealed/maintenance free.

Sixto
87 300D

You use them on a fully-charged battery, specific gravity will tell you the charge state of individual cells.

Often a battery dies because one cell is weaker than the others, this will lead to over-discharging of that cell, plus it will not allow the other cells to charge as completely, and finally because a multi-cell battery is like a chain in that the weakest cell (link) determines the strength.

Check all cells and look for the variation as well as the overall charge state.

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Gone to the dark side

- Jeff

I have one that is made for the Coolant to tell the Antifreeze/Coolant concentration.

If you have one for your battery there could be instructions somewhere on the internet on how to use one; or in the Library you might find an old Autor Repair Book that would tell you.

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84 300D, 82 Volvo 244Gl Diesel

I use one to tell me the specific gravity/potential Alcohol of my home brew.

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Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

i have one, and i know how to use it. im just curious if anyone here does.

and no, its not just for a fully charged battery. read my post on the "my battery died today,it was 16years old.) alot of time a good charge will equalize cells that arnt showing the same specific gravity

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have no worries.....President Obama swears "If you like your gun, you can keep it

Yeah, I know how and I also know how to convert specific gravity to concentration in %, molality, molarity, mole fraction, etc. Do you?

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Charles
1983 300D, bought new, 215k+ miles, donated to Purple Hearts veterans charity but I have parts for sale: http://www.peachparts.com/shopforum/mercedes-benz-cars-sale/296386-fs-1-owner-83-mb-300d-turbo-rebuild-parts.html

nope, didnt ask. all i was asking is if anyone uses them or knows how. i dont hear about anyone using them anymore. so let me ask you this. do YOU use it? or do you rely on a voltage reading?

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have no worries.....President Obama swears "If you like your gun, you can keep it

I'm a chemist and use them in routine standardization of a wide variety of chemical solutions.

For the car: I only use them on a weak car battery to find differences in cells. Before discarding the battery, I'll try to up a low cell reading to match the others by adding some sulfuric acid to that cell. It's usually not worth the effort as the battery life is only extended a short time.

I have used them on the coolant but now prefer to just change it on a regular basis. I use 50/50 (by volume) and don't check the sg. Winters are so mild here that more is not necessary.

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Charles
1983 300D, bought new, 215k+ miles, donated to Purple Hearts veterans charity but I have parts for sale: http://www.peachparts.com/shopforum/showthread.php?t=296386

Hydrometers are in common use in aircraft maintenance. They will provide a much better insight into the "health" of the battery than will voltage measurement. But, aircraft battery health is a safety matter; automotive battery health is mainly an issue of convenience.

agreed, but its not a bad thing to know/use.

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have no worries.....President Obama swears "If you like your gun, you can keep it

I didn't realize this was an "I know more than you do" thread.

Yes I use it, but not for disposable car batteries. The coach 8-D batteries weigh and cost much more than the car batteries, and in the battery array I can have one bad battery (cell) drag down the rest of them. Also in the coach I can equalize the batteries as they are open-cell batteries where the car battery doesn't have the plate construction to handle the heat without warping nor the capacity to vent gasses / add water properly for the equalization cycle, so they get tossed when weak.

I really consider a hydrometer fairly useless with modern car batteries.

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Gone to the dark side

- Jeff

Where did you get the idea I was belittling anyone? I simply stated that no one seems to use them (and some dont know how). My point was that it is a good tool to own and know how to use.

The only thing I said that could have been taken that way was "I have one and know how to use it" the way I worded the first post may have sounded like I was asking how to use one.

Maybe this is a lost process on car batteries. I agree a lot have gone to maintenance free, but I dont own any. I dont plan to either.

__________________
have no worries.....President Obama swears "If you like your gun, you can keep it