How to detect open circuit inside the battery?
With expert control trials (before opening) starter battery is not able to start the engine, the EMF which is often close to normal, and the charge goes to the ripple current value, use the method of searching for breaking the circuit inside the battery.
In charge mode (with plugs in the lid) with a voltmeter to measure voltage turn on Terminal for the electrolyte in the banks, leaving the touch probe from one bank to another, noting the change in the voltage measurement from the beginning. Each transition gives an increase of the voltage 2.0-2.5 V. In passing through a defective connection between the banks race tension will be more significant and may be 3.0-4.0 V, and more. Voltage measurement should be repeated on each pole battery cable (for reliability). For batteries manufactured without the traffic jams in the lid, the application of methods discussed above is possible only after drilling holes in the lid of each jar on the verified points. These points are marked in places where the two-layer cover has a hidden hole in the bottom layer. The opening of the indicator (it must be removed) can also be used.
If the battery for a long time, was inactive (stored) in a discharged state, then its fixed charge from a low-power charger is impossible. In this case, the required voltage to charge it may be of the order of 18-20 V and more. This case should not be taken as an open circuit. Measurement of the charging voltage of the electrolyte (the banks) will show that the transitions have almost equal values. Within one to two hours of the total charge on the battery voltage drops to 12.0-13.0 V, and then the charging process will go as usual. The high voltage required at the beginning of the charge due to the appearance of sulfate on the plates having a high electrical resistance at a low density of the electrolyte.