In comparison to traditional batteries, how long to rechargable batteries hold a charge?

Question

After being fully charged, the batteries die after about two hours of use in my daughters mobile, however traditional alkaline last about 28 hours. Is that normal?

Answer 1

It depends on the type of rechargeable battery and how you use them.

Ni-Cd (nickel cadnium) batteries tend to develop what is called charge memory. If you use them until they're about 50% discharged and then recharge them, they'll begin to lose their ability to discharge past that 50% level. They can be restored, however, by doing a deep discharge cycle. This is when you completely discharge the battery until it's completely dead, charge it back up to 100%, and repeat this a few times.

Ni-Cd batteries also don't have the ability to generate the current of other types of rechargeable batteries, including Ni-Mh (nickel metal hydride) or lithium ion batteries.

Ni-Mh batteries have a very high current rating and last a very long time in devices such as digital cameras. They also tend to not have the charging memory problems of Ni-Cd batteries.

Lithium ion batteries are the most commonly used in things like cell phones or laptops, where the battery pack is in an odd shape (like square or rectangular, instead of your standard cylindrical batteries). This is because the chemistry that occurs in the battery doesn't require the cylindrical shape, like the other batteries do. Lithium ion batteries also do not have the charge memory of the Ni-Cd batteries.

If you were to get a properly charged set of Ni-Mh or lithium ion batteries, I would bet that they would perform as well as or better than the alkalines. And, they would be rechargeable, too.