Many people experience a difference in weight when changing out a series of old batteries with new ones, but this doesn’t mean that dead batteries actually weigh less. When changing out standard batteries used in electronic devices, simply changing the battery brand can make the new battery “feel” heavier than the old one. Batteries vary by weight, by type and by brand.
Batteries typically weigh the same whether they are live or dead when they are made by the same company. The electrical charge within batteries has no weight, so when a battery discharges, all its internal elements are still in place. A person may feel as if the battery weighs less because he expects it to feel “empty,” but from a physics perspective, nothing in the battery’s weight has changed as the only thing missing from the battery is its electrical charge.
Batteries That Feel Lighter
Some alkaline batteries may feel lighter when changing them in electronics devices. If you notice a battery that feels a lot lighter than a new battery, this may be an indication that the battery case was compromised. When the battery case is comprised, it will leak its contents into your electrical device. Batteries that leak can damage your device. Always check the battery compartment in your electronic device for signs of leaking if the battery feels lighter.
Lead Acid Batteries
The only dead batteries that may actually feel lighter are lead acid batteries in cars. Car batteries weigh an average of 21.4 lb., according to the figures used for a study completed by the Battery Council International on battery recycling. The study captured data on the amount of lead available for recycling in used batteries. The study used two different numbers for calculating the amount of lead available for recycling, marking a difference in the weight of drained and undrained batteries by a drop in the lead weight.
Sulfuric Acid and Water
The other reason a lead acid car battery may feel lighter is due to the sulfuric acid and water in the battery. A new battery will be full of sulfuric acid, causing the battery to weigh more. A depleted or dead battery often is typically void of the sulfuric acid and water used in the charging process. Although this weight loss is not significant, it contributes to the lighter feeling in a lead-acid battery.
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