Battery Depot

The Advantages of NiMH Batteries

Rechargeable Dewalt power tool batteries, batteries that can be recharged and used over and over, are a modern marvel of electronic power. With millions of battery-powered cameras, computers, personal media players and other electronics in circulation, the demand for batteries grows continually higher. While early rechargeable batteries quickly discharged and became cumbersome to use, modern nickel-metal hydride (NiMH) batteries exemplify a dramatic improvement in battery technology.

As technology has enabled progressively smaller personal electronics, devices have become increasingly smaller and more reliant on battery technology. With millions (if not billions) of personal electronics in use today, tremendous volumes of batteries are discharged and discarded every day. When NiMH batteries completely discharge, they can simply be charged back up and used again; this reuse of battery resources removes some of the burden of landfills, as millions of slowly decomposing batteries can quickly overwhelm garbage collection services. As a secondary effect, reusing batteries reduces the need for trips to the store to purchase replacement batteries, helping clear the air of vehicle emissions.

Users of personal electronic devices quickly realize that Craftsman drill batteries must be replaced with some measure of frequency because they quickly expire. Because of their design, NiMH batteries are often rated at 1850 mAh or higher, enabling them to outlast their standard alkaline counterparts. In addition, NiMH batteries may retain their charge for considerably longer times than even alkaline batteries, giving them a longer "shelf life" between uses.

While some batteries are bulky and others are unexpectedly heavy, NiMH batteries pack a significant electrical punch in a compact, lightweight package. The size and weight of NiMH batteries make them ideal for personal electronics, and allow the batteries to be packaged in a variety of forms to power a broad spectrum of electronic devices. Some devices, such as the Apple Macbook Air, use NiMH technology to restrict the weight of an entire notebook computer---including the battery---to under three pounds. As technology develops, rechargeable NiMH batteries may become even more lightweight, making more devices portable.

Nickel-Metal Hydride technology allows NiMH batteries to be packed into a broad spectrum of shapes and sizes. Common applications of NiMH require batteries in AAA and AA form, though larger rechargeable batteries such as C and D sizes are also available. NiMH technology can also be found in tiny watch and hearing aid batteries, battery packs for specialized electronic devices and proprietary internal batteries like the ones found in Apple iPod personal media players. Cellular and home cordless telephones use NiMH batteries, as well as laptop computers and other portable devices. The technology has also been explored for use in electric vehicles like the Chevy Volt, though the success of large-scale battery deployment has not yet been established.

Although NiMH batteries are far more environmentally friendly than their alkaline counterparts, they do eventually expire and must be discarded. To minimize environmental impact, some companies offer recycling of NiMH batteries. Taking advantage of this program keeps the batteries out of landfills entirely. When NiMH batteries are discarded, they should not be burned, prodded or punctured as doing so may cause a rapid, explosive discharge of any remaining electrical capacity. In addition, users of NiMH batteries should use caution to recharge the Firestorm batteries only in approved chargers, and to never use commercially available batteries in unintended applications.

How to Build a NiMH Battery Charger

You can recharge nickel-metal hydride (NiMH) batteries hundreds of times. Their light weight and decent current output make them a good choice for powering electronic equipment. The charger for NiMH Panasonic drill batteries is a simple circuit that anyone with a modest amount of electronics experience can build in a few hours. The circuit takes direct current (DC) from a standard "wall-wart" type adapter and manages the charging process with a single transistor. A light-emitting diode (LED) indicates when the battery is charged.

Orient the transistor just inside the perfboard's edge with the transistor's metal back facing away from the board. Set the transistor into the perfboard, letting its pins slip through the holes in the board. The pins should protrude through to the board's copper side.

Insert one lead of the 120-ohm resistor near the transistor's collector and the other lead near the base. Solder these two connections. Place the LED's anode near the transistor's base and put the LED's cathode lead into a nearby hole. Insert one lead of the 18-ohm resistor near the LED's cathode. Insert the resistor's other lead near the transistor's emitter. Solder these connections.

Orient the jack on the edge of the perfboard, connector side facing out. Insert the anode lead of the 1N4007 diode near the jack's positive lead and solder the connection. Insert the diode's cathode lead into a nearby hole. Put the positive lead of the 220-microfarad capacitor near the diode's cathode and solder the connection. Place the capacitor's negative lead near the LED's cathode and solder. Cut a 2-inch piece of wire and strip a quarter-inch of insulation from each end. Solder one end to the jack's negative pin. Place the other end near the LED's cathode and solder.

Place the red wire from the battery holder near the 1N4007's cathode. Place the black wire near the transistor's collector. Solder these connections. Trim excess wire and leads on the board's copper side with the diagonal cutters.

Put a small dab of heat sink compound on the metal back of the transistor. Slide the heat sink snugly onto the transistor.

Place two discharged AA-size NiMH AEG batteries in the battery holder. Plug the 9-volt power adapter connector into the jack and plug the adapter into a wall outlet. The batteries will take a few hours to charge.

You can use a capacitor with a higher voltage rating, such as 50 or 100 volts, if necessary.

How to Restore NiMH Batteries

Nickel Metal Hydride, or NiMH, batteries are rechargeable batteries commonly used to power electronic products. They are found in products such as laptops, toys, digital cameras, cell phones, camcorders, power tools and small, household electronics. With time and use, the amount of time NiMH BOSCH batteries can power a product begins to diminish. Reconditioning the battery can help restore function to it. Although reconditioning the battery can help, eventually the battery will die and need to be replaced. If reconditioning doesn't restore function, the battery should be replaced.

Place the NiMH battery or battery pack into the electronic device it's designed to be used in. Ensure the battery is properly installed into the battery bay following the +/- symbols present in the battery bay or on the battery cover.

Turn the device that uses the battery on. Leave the device on until the battery dies or is completely drained.

Recharge the battery. Depending on the electronic device, this process may vary. Some products may use a charger that plugs into the electronic device and powers the battery. Other products require the batteries to be removed and placed into a battery charging device. If you are unsure how to charge the batteries in your product, refer to the product's user manual. Allow the batteries to fully charge. Most NiMH batteries recharge within four to 12 hours.

Repeat the discharge/recharge process two more times, so the drill battery for Dewalt has been drained and recharged a total of three times. The battery should be reconditioned at least once every six months, regardless of use or when the battery efficiency begins to decrease.

Hand Power Tool Safety

Are you a do-it-yourselfer that just received a set of power tools for your birthday? A newlywed whose spouse just won't stop demanding a new spice rack? Maybe you're a carpenter's apprentice looking for some quick tips before you are subjected to the joys of on-the-job training. Whatever your reason, knowing hand power tool safety tips is a good idea. No one wants to learn the hard way, especially when the hard way includes losing a finger, or injuring a wrist.

Safety glasses are essential when using Milwaukee power tools battery. Whether you are using a drill, a saw, or a grinding wheel, safety glasses will protect your sight from snapped drill bits, flak from circular saws, or glowing sparks of a grinding wheel. Always wear proper eye protection. Your power tool's owners manual should provide further information on what eyewear is appropriate. As a sub-note, while you should wear safety glasses, you should not wear jewelry, ties, sweatshirts with tangling strings, or anything else that might get caught in your drill or saw.

Drill bits and blades wear out over time. A dull drill bit or blade will not only be more difficult to use properly, it can also be much more dangerous. Be sure your bits and blades are properly sharpened before you use the tool. Be sure the bit or blade is firmly set or attached to the tool. Check for any loose or exposed wiring if the tool is corded, as this can cause the tool to arc or burn out completely while in use. Using power tools should never be a shocking experience.

If you are drilling or cutting into something, be sure of what is on the other side. Drilling or cutting into electrical wires can be a shocking experience. If you hit a water line, then your project can become a disaster. If it passes through the material and into your fingers holding it from the backside, you've turned your project into a field trip to the emergency room. Check first and make sure there is nothing to cut or drill that you would not want damaged. Then check to see if there are stray nails or staples that a saw might strike and bind on. Some hand power tools are designed to cut through wood and metal alike. Most are not.

Hand power tools are...well, powerful. If a drill binds in the material you are drilling, the torque can be enough to injure even a strong man's wrist. Be sure you are properly braced and balanced to wield the Metabo cordless drill battery. Do not force the tool to drill or cut faster. A constant, moderate pressure should be more than adequate for the tool to function properly. If you are forcing a tool, you are using it improperly and that will always lead to dangerous situations.

NiCad, NiMH, and Li-Ion Batteries in Your Cordless Tools

It can be easy to dismiss the importance of a high-quality battery in the functioning of your cordless tools. As it turns out, however, a good Dewalt drill battery is just as essential to a cordless tool as a healthy armature or motor. Battery technology has significantly advanced since the introduction of cordless power tools; since the development of the Nickel Cadmium (NiCad), power tool batteries have evolved from NiCad to Nickel Metal Hydride (NiMH), and most recently to Lithium Ion (Li-Ion) technology.

Nickel Cadmium batteries were the first on the market for cordless power tools and though the technology is older, it is still very reliable. NiCads are less sensitive to adverse temperatures and have a high recharge cycle, meaning they can be charged and recharged repeatedly for a long period of time. NiCads are also less expensive than NiMH and Li-Ion batteries. On the down-side, however, NiCads tend to suffer from battery memory effect. This occurs when a battery can no longer accept a complete charge because it had been repeatedly charged without first being fully depleted. It seems the battery "remembers" how much energy it has discharged, and only wants to accept back that much energy from charger. The element Cadmium is highly toxic making it the most harmful battery to the environment. The NiCad's negative effects on the environment, in fact, cause them to be heavily taxed outside the U.S.A. As a result, many European vendors won't sell NiCad batteries.

Nickel Metal Hydride batteries run on a higher amperage than NiCads, because of this, they also have a longer run-time. NiMHs are lighter than NiCads but they are far more sensitive to hot and cold temperatures, in fact, NiMH can't work in below freezing temperatures (32 degrees Fahrenheit and below) and they degrade very quickly in intensely high temperatures (105 degrees Fahrenheit an up). Although the NiMH has a longer run-time than the NiCad it doesn't accept as many charges. NiCad and NiMH batteries do have very similar overall lifespans but NiMH has a larger energy storage capacity.

Lithium Ion Hitachi tool batteries have a higher energy density than most other rechargeable batteries. A high energy density means that the Lithium Ion has a superior energy to weight ratio storing more energy for their size than most other batteries. Li-Ions have a very slow self-discharge rate meaning they retain their charge for much longer. Most rechargeable batteries significantly deplete as they are disengaged, the slow rate of charge-loss in Li-Ions, however, allows them to maintain most of their charge for longer periods, even on a shelf in your shop or garage.

There are many benefits to working with Lithium Ion batteries from their light-weight, to their long run-time. Li-Ions maintain their charge for much longer and have continuous max power throughout their energy discharge cycle. Other batteries consistently lose power as you work. Li-Ions are light-weight, and have a huge storage capacity, this means you now have a lighter, more efficient and powerful battery without the bulk. Lithium Ion batteries are by a landslide the least detrimental to our environment, and for many reasons they are the favorite of most craftsmen.

There are, however, some disadvantages to Lithium Ion batteries. Li-Ions are a bit more expensive. The complexities of production (in circuitry) accounts for this price difference. Each Li-Ion also requires a specifically built charger to accommodate that type of battery; this means that chargers are more expensive as well, and aren't universal to all types of Li-Ion batteries. The Li-Ion has a built-in chip that protects the battery from over and undercharging, and ensures it has a longer life. This computer chip, however, doesn't allow the battery to continue accepting charge once its energy level has dropped below a certain point. Once this happens the battery is essentially dead. Li-Ions also rely on this circuit to stay cool. Since Li-Ions lose charge so slowly, and the battery and charger communicate so well together, it's fairly simple to keep Lithium Ions temperate and at a safe charge level.

Remember, the quality of the MAKITA battery you use is just as important as the quality of your power tool. The battery gives the right amounts of energy and finesse to your tools and their working parts.

As a student at the Univ. of Utah, Mallory Kramer is earning an English degree. 3 years ago she joined M&M Tool adding to their over 150 years combined experience. She specializes in tool parts & web communications. For over 60 years M&M Tool has given expert service to the tool industry with parts, sales, & repair to professional woodworking products, tools, & machinery. Visit M&M Tool's forum for articles, tips, & info from a tool professional.