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Storing accumulators incorrectly can be costly

Publication date 12.11.2020 9.38 | Published in English on 13.11.2020 at 11.47
Press release

 Many modern devices and equipment, such as electric tools, garden machinery, electric bicycles and hoverboards, use lithium-ion accumulators. If you do not use an accumulator-powered device or vehicle during the winter, store it safely. Incorrect storing can ruin the accumulator and make it unusable when you get the item from storage after winter. In the worst-case scenario, the accumulator can catch fire when you charge it after storage.

Before storing the item, check the accumulator’s condition and charge it according to the item’s instructions. 

Before placing an accumulator in storage, visually check its condition and charge it. Lithium-ion accumulators should never be allowed to become fully depleted. It is recommended that accumulators are charged at least once during storage as well. 

–    ‘When charging a lithium-ion accumulator, always follow its instructions and those of the charger. Only use a high-quality and fully functional charger made for the item holding the accumulator. Always keep an eye on the charging item!  Never leave an accumulator to charge unsupervised, particularly in residential spaces or spaces with flammable material. Remove the charger from the device when the accumulator is fully charged’, says Senior Officer Jukka Lepistö from the Finnish Safety and Chemicals Agency (Tukes).

Do not charge accumulators in cold conditions. Although the accumulator warms up during charging, the cold air damages the accumulator and reduces its service life.
Do not use a charger if it looks damaged or functions inconsistently, or if the charger’s wires or connectors are damaged.  

–    ‘A faulty charger or accumulator can start a fire during charging. Burning lithium-ion accumulators can explode and they can be difficult to put out. A burning accumulator can set the device, the room or the whole house on fire’, Lepistö warns.

How to store lithium-ion accumulators safely

The accumulators should be stored in a dry space with good ventilation. They should not be stored in conditions that are too warm or too cold. The accumulator’s or the device’s instruction manual should have information on appropriate storing temperatures.

If an accumulator is stored in cold and humid conditions, it can be ruined and become unusable. Damaged accumulators are a fire hazard when they are charged. 

Devices equipped with lithium-ion accumulators or the accumulators themselves should be stored in normal room temperatures. Unsuitable storages include boiler rooms, mechanical rooms and cold outdoor storages. 

Store accumulators on a fire-resistant surface in a place with no fire load near the accumulator. Clothing and other textiles are examples of a fire load. The space where the accumulator is stored should also have a fire alarm. 

If a lithium-ion accumulator becomes damaged, for example due to being dropped, if it has dents, or if it becomes overheated and swollen, the accumulator must be placed in a location where its possible ignition cannot cause a larger fire.

Further information: 
Jukka Lepistö, Senior Officer, tel. +358 29 5052 460, email format: [email protected]

Tukes’s website includes information (in Finnish) aimed at consumers on the safe purchase, use and disposal of lithium-ion accumulators.

More information on recycling accumulators can be found at the address


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