Ni-Cad are maintenance free batteries and require very little attention other than the topping up at intervals of 6 to 8 months and charging only when the batteries go down.
Memory effect in Ni-cad batteries is responsible for the batteries holding less than an optimum charge. This phenomenon is difficult to explain here but suffice it to say that it occurs when you start charging the batteries that are not completely discharged. When you habitually charge batteries every day irrespective of the condition of battery, the memory effect takes control and reduces the level of battery full charge.
The Ni-cad batteries are to be charged only when they are completely discharged. If you suspect that the batteries are not getting charged completely, you should discharge the batteries completely and recharge them to full extent before using them.
Actually, the individual cells of battery batteries are to be discharged, but the batteries are sealed and as such, a common person does not have the facility for discharging individual cell.
Therefore, prevention is better than cure. Ni–cad batteries are to be used as per manufacturer’s recommendations and that means discharging them completely before charging. This has to be followed scrupulously every time.
In order that your battery serves you to full extent of its capacity, follow the following dos and don’ts
Recharge batteries only after they are completely discharged. In lead acid batteries, do not top up the battery completely. Leave space for hydrogen generated to escape. Do not allow the batteries without charging. Charge as soon as possible. Do not add acid at any time. Adding acid might overcharge the batteries. When the engine is running do not disconnect the battery