General description
Many different types and shapes of batteries can occur in IT appliances. Small batteries (i.e. button cells) are used to cover the permanent low energy supply for alarm and computer system (clock, memory backup, etc.). In contrast, bigger batteries (e.g. laptop batteries) allow to run the whole device. Most modern devices do not need the small batteries anymore because the permanent energy demand for the system is reduced on the one hand. On the other hand the remaining energy demand can be covered by the capacitors.
Composition / main substances of content
Heavy metals such as cadmium (Cd), nickel, (Ni), and to some extent zinc (Zn). Organic solvents, etc.
Cadmium (Cd) is extremely toxic even at low concentration. Breathing large levels of Cd severely damage the lungs and can cause death. Water contaminated with Cd severely irritates the stomach, leading to vomiting, and diarrhoea. Cd stays in the body for a long time and can build up in kidney, or lead to lung damage and fragile bones. It is a probable carcinogen. Cd is also used in silver solders or as stabilizer for plastics as well as in phosphorescent coatings in some CRT.
The most common harmful effect of nickel is an allergic reaction (skin rash, asthma) for people sensitive to it (10-20 % of the population). People working in nickel-processing plants have experienced chronic bronchitis and reduced lung function. Long use of drinking water contaminated with high concentration of nickel may lead to stomach ache and adverse effects to blood and kidneys. Ni compounds are known as carcinogens for human.
Zinc is an essential element in human diet. Zn deficiency results from inadequate intake of Zn and can cause problem (hair loss, diarrhoea, brain development retardation of foetus and young children). However, large doses are harmful which can cause stomach cramps, nausea, vomiting. Intake over a longer period can cause anaemia. Free Zn ion (Zn2+) in solution is highly toxic to plants, invertebrate and some fish.
Localisation in appliance
Batteries are very diverse in terms of characteristics, composition, form, size, colour, etc. Almost every IT-equipment contain at least one battery. Rechargeable accumulators can be found in mobile phones, laptops, toothbrush or electrical razors. Appliances like torches, portable CD players, etc. can be operated using rechargeable and non-rechargeable batteries. Small (button) cell batteries are often used as a backup battery to the main battery; it provides an independent energy supply for processors, timers, security backup, etc. in computers. It is commonly located on the PWB.
The following inscriptions can help to identify batteries and to distinguish from others components (capacitors, resistances). Inscription: + / -, Li-ion, NiCd, NiMH (nickel metal hybrid battery), alkaline (Zn/MnO2), "RAM", "Dallas", "Symphony", "Danger do not open", "Do not dispose in fire", "Timekeeper". Rectangle batteries are often disposed near the bios system of the motherboard, with the sign of a clock, or a dog.
Requirements for storage and transport
Avoid long time storing. Batteries are subject to corrosion and cell rupture, which could release reactive hazardous substances (heavy metal oxide, organic solvents, sulphuric acid).
Lithium-ion batteries can easily rupture, ignite, or explode when exposed to high temperatures, or direct sunlight.
Avoid fire risk and contact with heat sources. All batteries be stored acid-resistant barrels. They should be stored in a dry and sheltered place.
Caution during dismantling
!!! Never crush or open a battery!!!
There is usually no difficulty or risk to separate the batteries from their support if they are in good condition. Use gloves, and wash hands and throw the gloves away after contact with substances from defective and leaking batteries.
Caution during storage
Avoid long time storing. Batteries are subject to corrosion and cell rupture, which could release reactive hazardous substances (heavy metal oxide, organic solvents, sulphuric acid).
Avoid fire risk and contact with heat sources. All batteries be stored acid-resistant barrels. They should be stored in a dry and sheltered place.
Recovery and disposal options
Batteries should be treated in an adequate plant. In any case, they should not be incinerated in an open fire or with municipal waste.
Source of Information
Dismantling Guide for IT Equipment, which was elaborated within the SRI project and financially supported by SECO and UNIDO, June 2015