The optimization for measuring currents and firmware evaluation has been possible over a long series of conductivity measurements. A good correlation has been obtained between conductivity and battery capacity.
The use of a practical measuring method and a few basic conditions which were observed are causing a decrease in conductivity over time which indicated a decrease in capacity. This is true especially when aging is caused due to corrosion and dehydration.
The measurement of the conductivity is a comparative procedure where the conductivity is developed based on observation. The information can be obtained possibly based on methods that are related to the inside of the battery for a quick and reliable way.
Source:- Elektrotechnik.vogel