Powerman rechargeable batteries & battery chargers

Q: Can Ni-MH batteries replace alkaline batteries even though they are only 1.2 volts?

A: The nominal capacity of 1.2V for a rechargeable battery stands for its average capacity during discharge. When fully charged, the voltage will be around 1.45V.
For most electronic applications Ni-MH batteries are ideal substitutes even though alkaline batteries are rated at a nominal 1.5 volts. But alkalines deliver 1.5V only when they are fully charged. As they begin to discharge, the voltage of alkaline batteries continuously drops. During the course of their discharge, alkaline batteries average about 1.2V.
The main difference is that an alkaline battery starts at 1.5V and gradually drops to less than 1.0 volts. Once it gets to 50 % capacity or less, it will be delivering a lower voltage than a rechargeable battery (Ni-MH or Ni-Cd). Rechargeables stay at about 1.2 volts for most (80 %) of their discharge cycle.

Q: Is trickle charging harmful to batteries ?

A: What means trickle charge ? A trickle charge is a charge rate that is high enough to keep a battery fully charged, but low enough to avoid overcharging. Maintenance charge is another way to describe trickle charge.

It is not recommended long term (months at a time). If trickle charging is used, the charge current should be very low or only intermittent. The best smart chargers will only send an occasional pulse charge to the battery once it is charged. They do not apply a continuous low rate of charge .