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A battery converts chemical energy to electrical energy. Batteries are used for power on a wide variety of portable items and come in many sizes. They are commonly used in flashlights, cell phones, automobiles, portable electronics, appliances etc. There are different types of batteries including alkaline, NiCad, Lithium-ion, coin, button, and more.

Batteries eventually lose power. Rechargeable batteries can be charged, disposable batteries must not be charged.

Batteries supply direct current (DC) power. That means the current goes in only one direction. They are mostly low voltage (1.5 volts to 12 volts). Since batteries are low voltage, you can not get a dangerous shock from them.


Battery Safety

While there is no risk of shock from a battery, there are certain precautions you should take. Dry cell batteries contain a corrosive chemical paste and are sealed.

If they leak due to damage or an extreme discharge state, they could cause skin burns or damage to electronics or appliances they are installed in. Remove batteries from electronics or appliances if they will not be used for long periods of time.

Safety tips to avoid battery leakage, explosion, or arc flash:

Example lithium disposable battery warning:

Warning: Risk of fire. Battery can explode or leak and cause injury if installed backward, disassembled, charged, crushed, or exposed to fire or high temperatures.

Example Lithium-ion rechargeable battery warning:

Warning: To reduce the risk of fire or burns, do not disassemble, crush, or puncture; do not short external contacts; do not dispose of in fire or water.

Disposable Batteries

Disposable batteries include zinc-carbon, zinc chloride, alkaline, lithium, coin, and button. Since they are not rechargeable, they are thrown away when discharged. Zinc and alkaline batteries are ideal on loads that draw a low current including flashlights and TV remotes. Common sizes are AA, AAA, C, D, and 9 volt. These batteries can eventually leak when fully discharged.

Zinc-carbon and zinc chloride batteries - Zinc-carbon batteries are usually the ones included in new TV remotes and portable electronics. Zinc chloride batteries are also known as “heavy duty”.

Alkaline batteries - Alkaline batteries are a type of dry cell that lasts longer than zinc-carbon and zinc chloride.

Lithium batteries - Lithium batteries last longer and can accommodate a higher current draw than zinc-carbon, zinc chloride, and alkaline batteries. Lithium batteries are also known as “plus” or “extra”. They are used in cameras and flash attachments, etc.

Coin and button batteries - Coin and button batteries are found in hearing aids, watches, and small electronics.

Rechargeable Batteries

Rechargeable batteries need to be charged before first use. New rechargeable batteries are charged at 50 percent or less for long-term non-use. These batteries should be recycled after failure. You can drop off rechargeable batteries at certain home improvement stores.

Rechargeable batteries do not like extreme temperatures, either hot or cold, especially when charging. Check the owners manual for specific information

NiCad Batteries - NiCad (nickel-cadmium) batteries are often used in cordless power tools and appliances. They should be fully discharged before charging to avoid “memory effect” (batteries may not fully charge if not allowed to fully discharge). NiCad batteries can “self discharge” over time (battery discharges a small percentage without being used).

NiMH Batteries - NiMH (nickel-metal hydride) are replacing NiCad batteries (except for cordless power tools) because of higher capacities and are less toxic.

Li-ion Batteries - Li-ion (lithium-ion) batteries are a newer technology used in the same tools and appliances as NiCad. They are also used to power cell phones, tablets, laptop computers, digital cameras, and camcorders. Lithium-ion batteries last longer than NiCad and maintain voltage output better when close to fully discharge state.

Deep Cycle Batteries

Deep cycle batteries contain lead plates in a bath of acid. They are similar to car batteries, but do not provide high current for starting motors. Because the plates are thinner, they are better suited to supply power allowing for a discharge over time. They are used to supply power to travel trailers, golf carts, etc.

Marine Batteries

Marine batteries are a type of deep cycle that are suited for boats. They can start smaller outboard motors and provide power allowing for a discharge over time.

What if a Battery Leaks?

Dead and weak alkaline batteries may leak if left in an electrical device too long. When a battery leaks, there is often a white residue and possible corrosion where the leakage occurred. Replace dead or weak batteries right away or remove them for long term non-use. Always discard a battery that has leaked.

Alkaline batteries contain potassium hydroxide that could cause eye, skin, and respiratory irritation. Use rubber gloves, goggles, and work in a well ventilated area when cleaning a battery compartment that is not badly damaged.

To clean the white residue, use vinegar or lemon juice with a toothbrush or Q-tip. Repeat if necessary, then use a damp cloth to remove any residue. Either let dry for several hours or spray with a can of compressed air to quicken the drying time.

After drying is complete, install new batteries.

Battery Disposal

Zinc-carbon and alkaline can go into the household trash.

Car batteries are usually recycled when you buy a new one, otherwise they can be dropped off at an auto parts store.

All other batteries should not be placed into the trash. Instead, drop off at home improvement and office supply stores. Since the batteries may not be fully discharged, cover any exposed terminals with electrical tape to avoid arcing and possible fire.

How to Charge Batteries

As a general rule, rechargeable batteries should not be overcharged. Some chargers are “smart” using a red LED to indicate charging and a green LED to indicate a fully charged state. When the green LED is on, the charger shuts off and prevents overcharging. Overcharging can damage a rechargeable battery. There are usually limitations on temperature (extreme low and high) when charging a battery. Always refer to the user manual of the tool, appliance, or electronics when charging a battery.

Universal Battery Charger

How to Store Rechargeable Batteries

Refer to the owners manual for storing rechargeable batteries. Some owners manuals recommend storing at full charge, others recommend storing at about 50 percent. Always store in a dry environment below 80 degrees if possible.

Battery Testers

Batteries usually lose their charge slowly, they just don’t quit working. A battery tester is the best way to show the condition of a battery and every home should have one. How else would you know if a battery is starting to go bad? See the Battery Testers page for more information.

9 volt batteries contain six 1.5 volt batteries connected in series

Assortment of Batteries 9 volt battery inside view

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