Click to read further detail. Considering this, do NiCad batteries go bad?
As long as NiCads are kept sealed, and never short circuited or severely over charged, NiCad batteries are perfectly safe to use, and do not vent toxic material. If a NiCad battery is treated well, it should last to the 1000 cycle mark.
Secondly, how do I bring my battery back to life? Bring Dead Lead Acid Battery to Live Again
Also question is, can you shock a battery back to life?
The nicad battery reconditioning machine can be built to shock a nicad battery back to life, from that point on the battery can be recharged again. Fortunately, on the other hand, an ailing cell can often be shocked back to life if you force enough current through it to cause the short to burn away.
How long do NiCad batteries last?
approximately 18 months