Lithium Battery Safety

Standards

General safety recommendations for lithium batteries have been published in the standards  UL 1642 and IEC 60086-4.
For more information on UL, visit UL at: http://www.ul.com.
For more information on IEC standards visit the IEC at: http://www.iec.ch.

Safety Data Sheet Lithium Batteries
Download the Safety Data Sheet Lithium Batteries here .

General Safety Guidelines

Whenever batteries are used in an application steps need to be taken to ensure that they do not malfunction during operation. Tadiran take cell safety very sereously and they have many guidelines and recommendations for ensuring safety when using Tadiran Lithium batteries. This section gives details of safety against charging and forced discharge, much more information regarding the various tests Tadiran cells go through can be found in the Tadiran Technical Brochure; this is the latest brochure released by Tadiran, it is still branded Sonnenschein but the information is still up to date.

Protection against charging

Tadiran Lithium Thionyl Chloride bateries are primary non-recahrgeable cells and therefore need protection against charging, this is very important it the Lithum battery used are not the single power source in a circuit; the following measures are recommended by the Underwriters Laboratories (UL). The battey should not be connected in series with an electrical power source that would increase the forward current through the battery. The circuit for these cells shall include one of the following:

1.		Two suitable diodes in series with the battery to prevent any reverse (charging) current. The second diode provides protection if the other one fails.
2.		A blocking diode or the equivalent to prevent any reverse (charging) current and a resistor to limit current in case of a diode failure. The resistor should be sized to limit the reverse (charging) current to the maximums IR, max shown below.

In addition to this UL requirement which gives the safety limits, Tadiran recommends to limit the reverse (charging) current to values below 10 µA. This will ensure that service life is not affected.

Protection against forced discharge
Forced discharge of a cell can occur when it is connected in series with other cells and when it is not protected with a by-pass diode. In these cases the maximum continuous discharge currents have to be reduced to the following values  IF, max: