Accumulator cadmium-nickel

The Nickel - Cadmium or Ni-Cd is component entering the clothes industry of Accumulateur for, inter alia, laptops, the portable tooling, the emergency lighting. Batteries Ni-Cd are sensitive to the Ratchet effect.

Batteries Ni-Cd today are relatively exceeded in term of autonomy, they were supplanted towards 1990 by the batteries NiMH, themselves now competed with by the batteries Li-ion.

Advantages of NiCd

simple and fast Load, even after a long period of storage.
is reloaded easily even at low temperature.
Great lifespan of number of cycle of load and discharge.
Good performances at low temperature.
Résistance interns very weak,
easy Stockage, whatever its level of load.
Storage and simple transport.
Low costs.

Weaknesses of NiCd

energy Weak density.
car-discharge rather quickly (20%/month).
Sensitivity to the ratchet effect.
Pollutant.

Practical

When one speaks to discharge a battery completely that of course implies not to go down in lower part from 1 V/element. This is the minimal tension in lower part of which the element should never go down under penalty of partial destruction, even complete. The discharge proceeds in three phases:

Firstly a fast fall of the tension towards the value of 1,2 V/element.
Then a long beach where the tension remains stable with this value.
And finally a fast fall of the tension, it is there that it is imperatively necessary to stop the discharge before the destruction.
the length of these phases is function of the output current. For an optimal discharge, it is necessary to conform to the indications given by the manufacturer according to the technology and of the characteristics of the accumulator. According to their technology the accumulators can more or less output current for the same capacity.

Legislation

A very strict framing of the setting on the European market of this technology was instituted by the directive 2006/66/CE published in the CHEEK on September 6th, 2006. This framing will be effective as of the transposition in the national legislations of the 25 Member States of the European Union, transposition which must intervene in the 24 months which follow this publication date this directive. Inter alia Regulation S, this directive envisages the prohibition of the use of cadmium in the portable accumulators, except for the accumulators intended for the emergency systems and of alarm, like with medical equipment and the tools electric without wire.

Accumulators Ni-Cd designed for an industrial or professional use are not covered by this prohibition. Indeed powerful systems of collection and recycling at the end of the lifetime were set up by the producers, thus making it possible to prevent that they do not finish their days in the discharges or the incinerators.

See too

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