Best Practices For Battery Life

1. Is it better for DEWALT® batteries to be completely discharged before charging?

No. Just the opposite. You should stop using a battery as soon as you feel a substantial decrease in power from the tool. Completely running down a battery may damage it. Do not tape the trigger to run down the battery.

2. What is memory, and do DEWALT batteries have it?

Memory is one of many conditions which causes a loss of run-time. Memory is created from repetitive light use in the exact same application (i.e. Cordless Phones, Video Cameras, Electric Shavers, etc.) Our products rarely see light use or the exact same loads, due to variability from the user, the accessory size, as well as the material. The same variability which causes different run-times prevents our cells from developing memory. Power tools are considered high-drain applications. Memory typically develops in lower-drain rate applications, such as cordless phones, laptops, etc…, because the rate at which the battery is draining is continuously the same. Power tools draw higher currents and have sporadic drain rates minimizing the opportunity for the battery to develop a memory.

3. Does it hurt DEWALT batteries to leave them in the charger?

No. The DEWALT chargers have a maintenance mode which allows batteries to remain in the charger, maintaining a fully charged pack until the user is ready to work. If DEWALT NiCd batteries are stored outside of the charger, they will discharge naturally, 15-20% the first 24 hours, 7-10% the next day, and about 1% every day there after. NiCd batteries lose the bulk of the capacity when outside of the charger in the first 3 days. In fact, it is better for the battery to leave it in the charger to be sure it goes through Equalization and Maintenance Modes. One of the benefits of DEWALT XRP™ Lithium Ion batteries is that they have limited self discharge. Storing DEWALT Lithium Ion batteries outside of the charger will not result in loss of charge. Learn more about brushless tools technology.

4. What can I do to improve the run-time of my battery?

If no permanent damage has been done to your battery, you may be able to improve its run-time.The correct procedure for charging your batteries is as follows: 

• Discharge the battery under normal use. Remove the battery, once you feel a loss of power from the tool. Do not tape the trigger ON.
• Let the battery sit out of the charger for a least 2 hours until the battery is at room temperature. 
• Place the battery in the charger overnight to allow for a full charge on each individual cell (A minimum of 8 hours at room temperature). 

If there is no difference in run-time, there is either permanent damage or the battery has reached the end of its usable life. In either case, the battery should be replaced.

5. Does the outside temperature affect batteries? How?

Yes. If the batteries are too hot (105°F or higher) or too cold (below 40°F), the batteries will not take a full charge. Attempting to charge batteries outside the 40°F-105°F range can result in a permanent loss of run-time. When batteries are being charged and discharged, a chemical reaction is taking place, and if it is too hot or cold the chemical reaction is disturbed causing a loss of run-time.

6. Can the DEWALT charger be used with a generator?

Yes. All DEWALT chargers, excluding the DW9106, have been designed to handle the variations in voltage and current delivered by generators.

7. Should any special precautions be taken when transporting or traveling with batteries?

Transporting batteries can possibly cause fires if the battery terminals inadvertently come in contact with conductive materials such as keys, coins, hand tools and the like. The U.S. Department of Transportation Hazardous Material Regulations (HMR) actually prohibit transporting batteries in commerce or on airplanes (i.e. packed in suitcases and carryon luggage) UNLESS they are properly protected from short circuits. So anytime you transport individual batteries, make sure that the battery terminals are protected and well insulated from materials that could contact them and cause a short circuit. For more information consult the U.S. DOT website.

8. What should be done with batteries once they have gone bad?

Recycle them. DEWALT is an active participant with RBRC (Rechargeable Battery Recycling Corporation), the organization which is the international leader in the collection, transportation and recycling of NiCd cells. Old batteries should be disposed of at DEWALT Service Centers.

For more information call 1-800-8-BATTERY or 1-800-8-228-8379.