Battery Care and Maintenance

What is the difference between NiCad, NiMH and Lithium Ion batteries?

Batteries in portable consumer devices such as a laptop, camcorder, cellular phone, etc., are typically made using either Nickel Cadmium (NiCad), Nickel Metal Hydride (NiMH) or Lithium Ion (Li-Ion) battery cell chemistry. Each type of rechargeable battery chemistry has its own unique characteristics:

NiCad and NiMH:

The main difference between the two is that NiMH battery (the newer technology of the two) offers higher energy density than NiCads. In other words, the capacity of a NiMH is approximately twice the capacity of its NiCad counterpart. What this means is for you is increased run-time from the battery with no additional bulk or weight. NiMH also offers another major advantage: NiCad batteries tend to suffer from what is called the "memory effect". NiMH batteries are less prone to develop this problem and thus require less maintenance and conditioning. NiMH batteries are also environmentally friendlier than NiCad batteries since they do not contain heavy metals (which present serious landfill problems). Note: Not all devices can accept both NiCad or NiMH batteries.

Lithium Ion

Lithium-Ion (Li-Ion) has become the new standard for portable power in consumer devices. Li-Ion batteries produce the same energy as NiMH battery but weighs approximately 20%35% less. This is can make a noticeable difference in devices such as cellular phones, camcorders or notebook computers where the battery makes up a significant portion of the total weight. Another reason Li-Ion batteries have become so popular is that they do not suffer from the "memory effect" at all. They are also environmentally friendly because they don't contain toxic materials such as Cadmium or Mercury.

 The Do’s and Don’ts of Battery Use

Battery Do's:

Fully charge/discharge battery up to 4 cycles before achieving full capacity of a new battery

Fully discharge and then fully charge the battery every three to four weeks to keep maximize the cycle life.

Remove from the device and stored in a cool, dry, clean place if the battery will not be in use for a month or longer,

Recharge the battery after a storage period, usually if it has been sitting for more than three weeks.

Ensure maximum performance of the battery by optimizing the device's power management features. Refer to the manual for further instructions.

Battery Don'ts:

Do not short-circuit. A short-circuit may cause severe damage to the battery.

Do not drop, hit or otherwise abuse the battery as this may result in the exposure of the cell contents, which are corrosive.

Do not expose the battery to moisture or rain.

Keep battery away from fire or other sources of extreme heat. Do not incinerate. Exposure of battery to extreme heat may result in an explosion.
 

My new battery isn't charging. Is it defective?

Usually NO. New batteries come in a discharged condition and must be fully charged before use. It is recommended that you fully charge and discharge the new battery two to four times to allow it to reach its maximum rated capacity

It is generally recommend an overnight charge (approximately twelve hours). It is normal for a battery to become warm to the touch during charging and discharging.

When charging the battery for the first time, the device may indicate that charging is complete after just 10 or 15 minutes. This is a normal with rechargeable batteries. New batteries are hard for the device to charge; they have never been fully charged and not “broken in.” Sometimes the device's charger will stop charging a new battery before it is fully charged. If this happens, remove the battery from the device and then reinsert it. The charge cycle should begin again. This may happen several times during the first battery charge. Don't worry; it's perfectly normal.

How can I maximize the performance of my battery?

There are several steps you can take to help you get maximum performance from your battery:

Prevent the Memory Effect - Keep the battery healthy by fully charging and then fully discharging it at least once every two to three weeks. Exceptions to the rule are Li-Ion batteries which do not suffer from the memory effect.

Keep the Batteries Clean - It's a good idea to clean dirty battery contacts with a cotton swab and alcohol. This helps maintain a good connection between the battery and the portable device.

Exercise the Battery - Do not leave the battery dormant for long periods of time. We recommend using the battery at least once every two to three weeks. If a battery has not been used for a long period of time, perform the new battery procedure described above.

Battery Storage - If you don't plan on using the battery for a month or more, store it in a clean, dry, cool place away from heat and metal objects. NiCad, NiMH and Li-Ion batteries will self-discharge during storage; remember to recharge the batteries before use.

Sealed Lead Acid - ( SLA ) batteries must be kept at full charge during storage. This is usually achieved by using special trickle chargers. If you do not have a trickle charger, do not attempt to store SLA batteries for more than three months.

This information was originally found at http://is.med.ohio-state.edu/policies/battery.htm