Battery Depot

How to Compare NiMH Battery Chargers

A wide range of NiMH (Nickel-Metal Hydride) battery chargers exist, from small AA/AAA units to large models that charge several types of PANASONIC EY9231 batteries. The battery types, capacity and charging time are a few important aspects to compare when purchasing NiMH battery chargers.

Compare the different types/sizes of batteries the chargers can charge. It's best to have the widest variety of options available, though many people don't need to charge any C or nine-volt batteries for MAKITA ML903. Also consider the battery quantity different NiMH chargers can hold at one time.

Check how long the charger takes to charge a battery. Don't compare apples and oranges; it will certainly take longer to charge a D battery than a AA cell. It's also good if the charger has a charge timer function; this helps prevent overcharging, which can cause battery damage.

The ability to also charge NiCd (Nickel Cadmium) batteries remains useful if you already own rechargeables of this type, though otherwise unnecessary. Some NiCd/NiMH chargers have a discharge/conditioner feature. According to RadioShack, this function is only important for Ni-Cd BLACK & DECKER A18 batteries and unnecessary for NiMH batteries.

How to Use NiMH Drill Batteries

Since their introduction to the consumer market in 1989, nickel-metal hydride (NiMH) AEG BSB 18STX batteries have carved a niche in powering everything from electronic devices to electric vehicles. Older rechargeable dry cell technologies were limited by "memory effect," in which they do not recharge completely without being fully discharged. NiMH cells have no memory effect and can be fully recharged hundreds of times from any state of discharge. However, they do have a few practical limitations. Follow this guideline to learn where to use NiMH batteries to your best advantage and when it's better to use a different battery.

Use NiMH cells to power any high drain device, such as digital cameras, radios and telephones. Frequency of recharging will not affect the battery's output.

Avoid using NiMH batteries for HITACHI EB 1826HL in low demand or infrequently used devices that have no built-in charger, such as flashlights, remote controls or smoke detectors. NiMH cells have a self-discharge rate of as much as 1 percent per day, so using a conventional or alkaline battery, or a NiCad rechargeable is a better choice in seldom-used electronics.

Check the power requirements of devices using 9 Volt (PP3) batteries before choosing a NiMH to power it. NiMH PP3 batteries may have six, seven or eight cells and vary in voltage from 7.2 to 9.6.

Recharge NiMH cells as soon at the first sign they need charging. If the cells are arranged in series and one cell fully discharges before the rest, the other cells can drive the dead one's chemical reaction in reverse and cause irreversible damage.

Dispose of NiMH BAT026 batteries for Bosch in your household trash, and take them to a recycling center. They're considered environmentally friendly, but some components can be reused.

How to Charge Nimh Tool Battery Packs

Nickel metal hydride (NiMH) batteries offer special charging challenges over other rechargeable batteries for Bosch 2 607 335 215. Overcharging a NiMH battery will cause the battery or battery pack to overheat and shorten the life of the battery. Using a battery charger designed to charge NiMH batteries will ensure the battery is not overcharged. These types of battery charges utilize a full charge limit switch that turns off the charger before the battery overcharges and in turn reduces overheating.

Discharge the NiMH battery using the device the battery powers. Make sure the battery is fully discharged before continuing.

Connect the male plug coming from the NiMH battery pack to the female plug coming from the NiMH battery charger.

Turn the dial of the battery charger to the voltage stamped on the NiMH battery pack. Plug in the charger. Set the charge time (if applicable.)

Turn on the battery charger.

Touch the HITACHI EB 920HS battery with one finger to feel for heat buildup in the battery. Turn off the battery charger if the battery starts to heat up to a point it is too hot to touch.

Disconnect the female battery charger plug from the male plug of the battery. Connect the battery to the device to ensure a full charge.

How to Jolt a Nicad Battery Back to Life

You have purchased expensive reusable nickel-cadmium batteries in the hopes of saving money in the long run. Instead, you are met with frustration because the Panasonic drill batteries no longer hold charge. Fortunately, there is a solution known as jolting, or zapping, using common items found in the garage. If not exercised regularly, nickel-based rechargeables develop an inner crystalline formation, which degrades the charge quality. Jolt your nicads using a 12-volt DC power source to break up crystallization, thus saving you money.

Wear all proper safety equipment. Set your volt-meter to the proper range for your battery. Hold the red lead on the positive battery terminal, and the black lead to the negative terminal. Read the meter: If the tested voltage is under 90 percent of the voltage labeled on the battery, then it needs to be jolted.

Separate the alligator clips from the 12-volt battery charger so they are not touching anything conductive. Turn on the battery charger. Hold the red/positive clip to the positive terminal of the worn battery. Tap the black/negative clip against the negative battery terminal 10 times, taking care not to hold a connection. Repeat this process for each worn nicad battery you have.

Test each battery again: if the reading is still below 90 percent, repeat the jolting process until a desired reading is achieved. Shut off the battery charger. Recharge the refurbished batteries in their respective chargers for the factory recommended amount of time.

Fully discharge and recharge your nicad batteries every few uses to avoid the need for future jolting.

Only jolt nickel-cadmium (Ni-Cd) batteries, as other battery types may explode.

Do not HOLD the alligator clips on the Ryobi drill battery, as they may overheat or leak.

How to Test Rechargeable NiCd Batteries

A rechargeable NiCd battery produces 1.2 volts and about 800 milliamp hours (mAh) when fully charged and in good condition. Milliamp hours relate to the time you can expect your battery to last based upon the milliamp consumption of the device it powers. For example, if your battery produces 800 mAh and the device it powers consumes 400 mAh your Panasonic power tool battery will last 2 hours. However, the charging and discharging process gradually reduces the battery's ability to maintain full mAh, so after a period of time you find that the NiCd battery goes dead quickly. You can test the condition of your NiCd battery by using a multimeter.

Read the label on the side of your NiCd rechargeable battery. It indicates the mAh the battery produces when new and fully charged. Make a note of the figure.

Charge your NiCd battery. Depending on your charger, the LED light will either change color or turn off when the battery is fully charged.

Remove the NiCd battery from the charger and let the battery rest and cool for about an hour. Don't put it in the device it powers. If you test your battery immediately after removing it from the charger you will get a false reading.

Turn on your multimeter. Select mAh on the control panel. You may need to press a button or turn a dial, depending on the type of meter you have.

Hold the prongs on the end of the two wires from the meter in your hands. Place the tips on the end of the prongs on the NiCd Ryobi battery terminals. The red prong goes to the "+" terminal and the black prong goes to the "-" terminal.

Read the meter display panel. The mAh reading will be the same or very similar to the mAh on the battery label, if your battery is in good condition. The lower the reading, the worse the condition of your battery.

Calculate the percentage mAh your battery is producing. This gives you a better idea of the state of your battery. Divide the mAh reading from the meter by the mAh on the battery label and then multiply the result by 100 using a calculator. For example, if the meter reading is 650 mAh and the battery label is 800 mAh then divide 650 by 800 to get 0.81, then multiply by 100 to get 81. This means your AEG drill battery is 81 percent charged. If the calculation results in a figure below 75 percent, you need to consider getting a replacement shortly.