The Telia tests norms 

 Telia developed after the above mentioned scientifical study a test program designated BKYA 10102. These tests have become norms on the Nordic battery market. The two most important requirements the vents must satisfy are to prevent explosions in batteries and to allow gages to leave a battery even when the gas pressure in the battery is low. The pressure drop in the vent should be accordingly low.

Sanpox has studied tests norms of other countries and found no norms more severe than the Telia norms.

Explosion risks

Other requirements are that it should be possible to refill water and to measure temperature and density of the battery fluid without removing the vent. The reason is that the explosion risk is greatest when the battery is opened. Even relatively small quantities of gas may explode and cause sprinkling of acid on clothes and eyes. Batteries have also been blown up.

Outstreaming gas

The study which Telia carried out showed that accidents happened mainly by ignition of gas that streamed out of the battery, only exceptionally by short-circuit in the battery. Explosions occurred usually when somebody touched the battery during service, cleaning up or other work in the room.

At low air humidity static electricity could cause igniting sparks from clothes of synthetic fibres or when shoes with rubber soles were used.

Earlier used vents or openings for ventilation showed high explosion risks.