Rechargeable NiCad Power Tools Battery Tips

Memory Effect

NiCad batteries are prone to what is referred to as the “memory effect”. What this means is that if a battery is repeatedly only partially discharged before recharging, the battery “forgets” that it has the capacity to further discharge all the way down. To illustrate: If a tool operator, on a regular basis, fully charges a NiCad batteryand then uses only 50% of its capacity before the next recharge, eventually the battery will become unaware of its extra 50% capacity which has remained unused. The power tool battery will remain functional, but only at 50% of its original capacity. The way to avoid the “memory effect” is to fully cycle (fully charge and then fully discharge) the battery at least once every two to three months. Simply leaving the device in the ON position and letting it run can discharge batteries completely. This will help insure the battery remains healthy. Once discharged, recharge the battery completely according to the manufacturer’s instructions. If your battery is Li-ion Battery, you will not have this problem, such as laptop battery, which usually use li-ion battery.

Battery Life time

The average life* of a rechargeable NiCad battery used in most portable power tools, operating under normal conditions and care, is generally between 300 to 500 charge-discharge cycles. This translates into approximately three years of battery life for the average portable power tool user.

As the rechargeable battery begins to die, the user will usually notice a decline in the running time of the battery. Example: When a battery that originally operated the tool for three hours of use is now only supplying the user with one hour worth of use, it’s time for a new battery.


Maximizing Battery Performance

There are several steps that can be taken to maximize the life and performance from the rechargeable battery. Below are some of the most common recommended practices to promote a healthy and longer life cycle of  NiCad type batteries.

Break-In New Batteries: New NiCad batteries generally come in a somewhat discharged condition and must be fully charged before use. It is recommended that new batteries be fully charged, fully discharged and subsequently fully recharged approximately two to four times to allow them to reach its maximum rated capacity. To prevent the Memory Effect (see above) keep the battery healthy by fully charged and then fully discharging it periodically.

Keep the power tool Batteries Clean: It’s a good idea to periodically clean dirty batterycontacts with a cotton swab and alcohol. This helps maintain a good connection between the battery and the 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 batteryhas not been used for a long period of time, perform the new battery break in procedure described above.

Battery Storage: If you don’t plan on using the battery for a month or more, we recommend storing it in a clean, dry, cool place away from extreme heat or cold and away from contact with metal objects. NiCad batteries will self-discharge during storage, therefore it is recommended to break-in the battery again (see above) before returning a stored battery to regular use.

NiCad Battery Charger: It is important to use only the battery charger that is specifically matched to the battery and approved for use by the battery manufacturer. Most NiCad battery chargers are durable and if taken care of normally last the full lifetime of the associated tool. However, there are those rare occasions where thebattery charger may need to be replaced with a new one. Since most of these style chargers are draw-dependent, internally-regulated and for the most part non-repairable, the testing of these chargers is not something the average consumer or service center can readily do. If the battery charger is not charging a relatively new battery or for some other reason is suspect, such as the charger suddenly feels unusually cold or unusually warm to the touch during charging, replacement of the charger may be necessary.

* The average life and discharge recharge cycle data are for reference use only. As explained, there are many and various conditions that can positively and/or negatively influence the outcome of a particular battery actual life cycle.

Filed Under: Used Power Tools


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