Weight of a battery

[barry wilkins]

Does a battery increase in mass when it is charged?
With a lead acid battery the specific gravity increases as it is charged (SG 1.1 to 1.25) .So the electrolyte must increase in mass ?
Perhaps the the paste on the lead plates absorb the mass as the battery discharges ?

Barry Wilkins

[joshnz]

Re: Weight of a battery

I''m not sure but I seen a video of a battery that bounced a different number of times when dropped charged and discharged.

so i do think battery's do change mass depending on charge.

[berniedd]

Re: Weight of a battery

Nope, mass didn't change. What did change was the acid became more concentrated as the charging current drove off the sulfate from the lead grids to change back to the original sulfuric acid in the electrolyte. In the process, the lead sulfate also changed back to lead. When you discharge the battery the sulfuric acid combines with the lead to form lead sulfate and hydrogen gas.

[Kiriakos GR]

Re: Weight of a battery

With a lead acid battery the specific gravity increases as it is charged (SG 1.1 to 1.25) .So the electrolyte must increase in mass ?

I will give you an example with sea water.
The sea water with low salt level works against the gravity effect because it is more water to it than salt.

One small container which can hold 300grams of salt water it is always 300grams no matter how much salt/water ratio is in it.

If factors as chemistry properties (activated by the charging) influences the composition of the liquid in salt which previously were attached on the battery plates this changes the gravity effect of the liquid, but not the total weight, the salt it just returned back in the water.

[eccerr0r]

Re: Weight of a battery

At best, charging a battery will cause it to lose mass due to electrolysis or boiling/evaporation of the electrolyte.
Discharging a battery should not cause any mass change either, unless you cause it to overheat and once again boil/evaporate the electrolyte.

Matter cannot be destroyed unless it's converted to energy...and it should be an immense amount of energy according to Einstein.

[kc8adu]

Re: Weight of a battery

i can tell you that a dead 8d weighs the same as a charged one.
had a dead one on one shoulder and a fully charged one on the other.felt balanced to me!

[cheapie]

Re: Weight of a battery

Anybody ever heard of the law of conservation of mass?

[Kiriakos GR]

Re: Weight of a battery

People do not get confused , the actual title of this topic is Specific Gravity of Battery Electrolyte ..

http://www.engineersedge.com/battery...ty_battery.htm

My father was a Cars electrician therefore I did understand the question but I tried to simplify the answer a lot.