Labeling of secondary (rechargeable) batteries for medical devices
In this article we decided to shed light on the features of labelling secondary (rechargeable) batteries for medical products in the Russian Federation.
To begin with, let us describe types of rechargeable batteries and terms used in relation to such batteries. Consider the diagram on the figure below based on the standard GOST R MEK 60050-482-2011 Chemical Sources of Electrical Current (it is identical to IEC 60050-482:2004 International Electrotechnical Vocabulary, Part 482: Primary and secondary cells and batteries):
At the top there is a “chemical source of electrical current” (Cell). The term is self-explanatory, it provides a simplified idea of what this source is like. However, let us provide a definition:
“The main functional device composed of electrodes, electrolyte, tank, pins and separations where electrical energy is produced by way of direct conversion of chemical energy.”
If the charge of the chemical current source cannot be recovered after discharge, such source is labelled as the Primary Cell. If the charge is recoverable then the source is labelled as the Secondary Cell. The term Primary Battery or Secondary Battery is the name of single or multiple Primary Cells or Secondary Cells with additional devices and an enclosure allowing them to be used as intended. To simplify identification of batteries that can be recharged, in English they are often named as Rechargeable Batteries, while in Russian the term ‘Аккумулятор’ (Accumulator) is commonly used.
On the diagram above, the next level could be a grouping of devices by type of materials used in the battery. Let us specify the main types of rechargeable batteries:
- Lead acid battery;
- Nickel cadmium battery;
- Nickel iron battery;
- Nickel zinc battery;
- Silver oxide cadmium battery;
- Silver zinc battery;
- Lithium ion battery;
- Nickel-metal hydride battery.
Recently, the following types have been the most widespread:
- Nickel cadmium battery – Ni-Cd;
- Lithium ion battery – Li-ion;
- Nickel-metal hydride battery – NiMH.
Today, labelling for the popular types of rechargeable batteries is governed in the Russian Federation mainly through the following standards:
- GOST R MEK 61951-1-2004 Rechargeable Batteries Containing Alkaline and Other Non-Acid Electrolytes. Portable Sealed Rechargeable Batteries. Part 1. Nickel cadmium (identical to IEC 61951-1:2001 Secondary cells and batteries containing alkaline or other non-acid electrolytes – Portable sealed rechargeable single cells – Part 1: Nickel-cadmium);
- GOST R MEK 61960-2007 Accumulators and Rechargeable Batteries Containing Alkaline or Other Non-Acid Electrolytes. Lithium Accumulators and Rechargeable Batteries for Portable Use (identical to IEC 61960:2003 Secondary cells and batteries containing alkaline or other non-acid electrolytes – Secondary lithium cells and batteries for portable applications);
- GOST R MEK 61951-2-2007 Rechargeable Batteries Containing Alkaline and Other Non-Acid Electrolytes. Portable Sealed Rechargeable Batteries. Part 2. Nickel-metal hydride (identical to IEC 61960:2003 Secondary cells and batteries containing alkaline or other non-acid electrolytes. Portable sealed rechargeable single cells. Part 2. Nickel-metal hydride).
Summing up the requirements for the labelling of various types of rechargeable batteries, the following must be specified:
- Identification of the rechargeable battery type:
- Rechargeable Li or Li-ion;
- Sealed rechargeable nickel-cadmium or Ni-Cd;
- Sealed rechargeable nickel-metal hydride or Ni-MH.
- Labelling of a rechargeable battery based on its type, construction, shape, dimensions and parameters according to the applicable standard;
- Rated capacity;
- Rated voltage;
- Manufacture date (it may be coded);
- Name or notation of the manufacturer or supplier;
- Recommended mode and duration of charging (not applicable to Li-ion rechargeable batteries).
The way to encode labelling of rechargeable batteries is described in a simplified form below. Li-ion rechargeable batteries may be cylindrical and prism-shaped, NiMH and NiCd may be cylindrical, disk-, and prism-shaped.
A) Labelling of Li-ion
Labelling of Li-ion rechargeable batteries must have the following structure:
N1 is the number of accumulators connected in series in a rechargeable battery.
A1 is the identification of the negative electrode system: I for Li-ion, L for lithium metal or lithium alloy.
A2 is the identification of the positive electrode system: С for cobalt, N for nickel, V for vanadium, T for titanium.
A3 is the identification of a rechargeable battery’s shape: R for cylindrical, P for prism-shaped.
N2 is the maximum diameter for cylindrical rechargeable batteries, or maximum thickness for prism-shaped rechargeable batteries (in mm), rounded to the next integer.
N3 is the maximum width of prism-shaped rechargeable batteries (in mm), rounded to the next integer. It is not specified for cylindrical rechargeable batteries.
N4 is the maximum height (in mm). In the event that dimensions are less than 1 mm, the module used is expressed in tenths of a millimetre, and a single number is specified as ‘tN’.
N5 is the number of accumulators connected in parallel. It is specified when multiple accumulators are used.
a) ICR19/66 stands for a cylindrical lithium-ion rechargeable battery with a cobalt based positive electrode, diameter between 18 and 19 mm, and height between 65 and 66 mm;
b) 1ICP20/68/70-2 stands for a prism-shaped lithium-ion rechargeable battery made up of two accumulators connected in parallel with a cobalt based positive electrode, thickness between 19 and 20mm, width between 67 and 68 mm, and height between 69 and 70 mm.
B) Labelling of NiMH and NiCd
Let’s draw up a table for labelling of NiMH and NiCd rechargeable batteries.
|Group of symbols **||First||Second||Third||Fourth|
|Group interpretation||Type||Shape||Discharge mode||Width or Diameter (in mm) 2/3 symbols||Thickness (in mm), 2 symbols||Height (in mm), 2/3 symbols|
|Type of rechargeable battery|
|Cylindrical NiCd||K||R||L||Diameter DD||–||Height HH|
|Disk-shaped NiCd||K||B||L||Diameter DDD||–||Height HHH|
|Prism-shaped NiCd||K||F||–||Width WW||Thickness TT||Height HH|
|Cylindrical NiMH||H||R||L||Diameter DD||–||Height HH|
|Disk-shaped NiMH||H||B||–||Diameter DDD||–||Height HHH|
|Prism shaped NiMH||H||F||–||Width WW||Thickness TT||Height HH|
* In this case, T stands for the ability to operate in the long-lasting discharge mode at high temperature (usually above 40°С).
** In notations of rechargeable batteries, groups of symbols are separated by a slash (/).
a) HRXR 23/43 stands for a cylindrical NiMH rechargeable battery with ultrashort discharge mode also designed to operate in fast charge mode with a maximum diameter of 23 mm and maximum height of 43 mm.
b) KBL 116/055 stands for a disk-shaped NiCd rechargeable battery with long-lasting discharge mode 11.6 mm thick and 5.5 mm high.
c) HF 18/07/49 stands for a prism-shaped NiMH rechargeable battery with a maximum width of 18 mm, maximum thickness of 7 mm and maximum height 49 mm.
Let us consider the main observations regarding the labelling of rechargeable batteries for medical products when they are officially registered in the Russian Federation. As may be inferred from the above list of standards, national standards are identical to those of IEC, even though they are obsolete. However, in the applicable standards of IEC that are still valid (which replaced those already specified or in updated revisions), the requirements for labelling have essentially remained unchanged. In other words, the requirements of Russian standards for labelling of rechargeable batteries are not unique: they are valid in many countries. As a result, the most frequent observation regarding the labelling of rechargeable batteries is related to the absence of the afore-mentioned labelling rather than to the failure to meet the requirements of applicable national standards. Another problem is the failure to provide a Russian translation of the original labelling. And while the second problem is excusable and explained by the lack of knowledge regarding local regulations, the absence of labelling causes due astonishment in the Federal Service for Monitoring in Healthcare and its expert centers.
On a final note, we’d like to underline the requirement to indicate special warning labels on transport containers used to ship medical products with rechargeable batteries. For example, for lithium-ion rechargeable batteries, the following symbols are appropriate (as per GOST 19443-88 «Dangerous goods. Classification and marking»):
– Lithium batteries: the symbol of UN number 3090 (UN3090);
– Lithium batteries installed in equipment: the symbol of UN number 3091 (UN3091).