Do Rechargeable Batteries Lose Charge When Not in Use?

If you own rechargeable batteries, you might wonder if they lose charge when not in use. The answer is yes, rechargeable batteries do lose charge when not in use, but the rate at which they lose charge depends on various factors. In this article, we will explore the reasons why rechargeable batteries lose charge when not in use, how long they last when not in use, how long they take to charge, and whether it’s okay to leave them plugged in.

How Long Do Rechargeable Batteries Last When Not in Use?

The amount of time that rechargeable batteries last when not in use depends on several factors. The first factor is the type of battery. Nickel-cadmium (NiCad) batteries tend to lose charge faster than nickel-metal hydride (NiMH) batteries. Li-ion batteries, on the other hand, have a very slow self-discharge rate and can retain their charge for months.

The second factor that affects how long rechargeable batteries last when not in use is the storage temperature. Batteries stored in a cool, dry place tend to retain their charge longer than those stored in warm or humid environments.

Generally, rechargeable batteries lose about 1-5% of their charge per day when not in use. This means that after a month or two, the battery may be completely discharged, depending on its initial charge level and the factors mentioned above.

How Long Do Rechargeable Batteries Take to Charge?

The time it takes to charge a rechargeable battery depends on its capacity, the type of charger, and the charging current. Typically, it takes 1-2 hours to charge a NiMH or Li-ion battery using a fast charger. A slow charger may take up to 12 hours to charge the same battery.

NiCad batteries, on the other hand, require a special charger that can discharge them before charging. This process can take several hours, depending on the battery’s capacity.

Why Do Rechargeable Batteries Lose Charge When Not in Use?

Rechargeable batteries lose charge when not in use due to a process called self-discharge. Self-discharge occurs when the battery’s internal chemical reactions continue to occur even when the battery is not in use. This process gradually depletes the battery’s energy, causing it to lose charge.

Self-discharge is affected by several factors, including the battery’s chemistry, temperature, and age. As mentioned earlier, some battery chemistries have a higher self-discharge rate than others.

Is It OK to Leave Rechargeable Batteries Plugged In?

It’s generally safe to leave rechargeable batteries plugged in, but it’s not recommended. Leaving the battery plugged in after it’s fully charged can cause it to overheat and reduce its overall lifespan. It’s best to unplug the battery once it’s fully charged and store it in a cool, dry place until you need it.

In conclusion, rechargeable batteries do lose charge when not in use, but the rate at which they lose charge depends on various factors. To ensure your batteries last as long as possible, store them in a cool, dry place, and avoid leaving them plugged in after they’re fully charged.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.