What is battery storage?
Battery storage consists in storing new equipment and sometimes waste to be recycled, containing toxic products and an electrical charge that needs to be preserved over time. As the storage temperature is ideally set around 15°C, the battery storage warehouse must adapt its environment according to its geographical location and weather. The storage space must be dry and well-ventilated. It must be adapted to the type of battery stored, and its components.
For instance, lithium-based batteries which are poorly stored risk exploding and catching fire when stored in warehouses. These common accidents are caused by short-circuits occurring near solvents and lithium, which are flammable materials. All supply chain stakeholders run these risks - first and foremost the battery storage area.
Battery storage is a high-risk operation, so products need to be constantly monitored and checked. This kind of activity requires specific equipment, such as dedicated containers for new batteries, or storage barrels for batteries to be recycled.
Specificities of battery storage in containers
The recommended storage temperature for most batteries is 15°C, with a full range going from -40°C to +50°C.
For instance, lithium-ion batteries are ideally stored in a box or container:
- That was specially designed to contain the provisional stock corresponding to upcoming sales;
- That has an inside and outside fire protection;
- That is not only air-conditioned, but also has anti-explosion vents that automatically open if necessary on the roof;
- With forced ventilation, so the room’s air can be renewed every two hours to ensure optimal safety.
This type of battery storage container is suitable for all countries, and ideally set up outside. This being said, inside storage is also possible.
Examples and practical applications
Battery storage based on typology
Lithium batteries
In the case where batteries to be recycled are mostly lithium-based, containers must be secured with alternating layers of vermiculite. This prevents the batteries from knocking into each other during transport or handling, and limits heat propagation. The potential fire caused by the batteries will therefore not spread within the metal tank. The tanks are placed on pallets to make handling easier, and moved using a forklift.
Maximum storage is so long-term that is has not even been defined for lithium-based batteries. On the other hand, if the batteries run flat (Li-ion lower than 2 V/cell), a shunt will form within the cells, leading to a short-circuit.
Lead and acid-based batteries
A lead-acid battery that is still wrapped can remain as new for about two years. Obviously, this storage time is impossible for a logistician, who needs to test the batteries regularly and recharge them to remain compliant with manufacturer standards. The danger with insufficient charging lies in sulphation, which prevents electrical circulation.
Nickel-based batteries
Storage for this type of battery usually requires a charge of about 40%. Loss of capacity over time is minimal, and the battery will remain functional. Nickel-based batteries can be stored with no charge at all, without this hindering their operation once charged. Maximum storage time for nickel batteries is 3 to 5 years.
Alkaline battery storage
Alkaline and primary batteries can easily be stored at cool room temperature, in a place with about 50% humidity.
Regulatory cornerstones
- Environmental Code, book V, title IV, CHAPTER III, section 7.
- Extended producer responsibility (EPR) makes producers responsible for the entire life cycle of the products they sell.
European laws stipulate producers’ responsibility according to the products sold.
[1] Source of the figures: https://www.corepile.fr/corepile/donnees-cles/