Lead Acid Battery Gravity Measurement

Its specific gravity.Its a ratio and please do some research on any topic before you want to present it.

Specific gravity is used to test one aspect of a wet cell battery. There are other conditions inside the battery that can make the unit not function as required. The device your looking for is called a hydrometer, that will show the specific gravity in the range needed for use with batteries.

Wet cell batteries have become less serviceable over the last 10-15 years. It is cheaper to replace them, then to fool around with the electrolyte's etc.

looking for electronic measurement with the units fitted on lid. It should be inexpensive and may be of cost at 10% max of the battery cost. Handheld hydrometers needs a person to do the job. I am looking for a simple gadget.

It's an interesting challenge. Really horrible environment for anything electrical - the sulphuric acid gets everywhere and will damage most materials. Best bet seems a float carrying a grey scale or variable width slot, with LED and photocell to measure the light passing through it. But then you need a pump to extract acid from the cell and pump it back after (no space inside battery for the mechanism). And all of that for every cell.

There is an electronic instrument available . check the possiblity of useing the same for checking of SG of batteries.

Read link www.densityanalytics.com

You may want it, but it is still a pointless exercise. You were unable formulate a sound reason for it.

If you have a digital data collection device, cell voltage, cell current, cell temperature provides all you need to know the health of a cell. Compare that to a fixed map in memory, and you are done (for anything outside of a research lab, that is).

These days an electronic non intrusive method is available from Midtronics. Nearly all dealerships use these testers and you can buy an hnd held model for a reasonable price. They will not only test flooded but sealed maintenance free wet cells and sealed AGM and Gel. In addition to state of charge it measures extent of sulfation & presence of internal cell shorts.

http://www.midtronics.com/

Electronically not possible. I think (not sure) Kilo batteries (wet 10000Ah to 65000Ah) have electrolyte circulation system and use conventional sp.g measuring system.

brzk,

Your suggestion is absolute nonsense. The mass inside the cell does not change. Discharging is simply a chemical reaction wherein the sulfate molecules leave the electrolyte and combine with the lead/lead oxide plates. O2 from the lead oxide joins with the dissociated hydrogen in the electrolyte to form water. All material remains in the cell jar so the weight will remain constant.