Charging nicad battery pack

Question

I have a motorola handheld radio when i put the battery in the charger it will rapid charge for 1hr then go to trickle charge how long should i leave it in the charger i have been told 2hr after rapid is done and told 12hrs the packs cost a bit so can someone please help so i dont mess them up thanks

Answer 1

The issue with long charge times is heat.  When you charge a battery, either using a fast charger or slow charge, the power going into it reverses the chemical action to the state it needs to be in to produce electricity again.  When the battery is charged, the power going into the battery simply turns to heat.  If the battery gets too hot it will vent to prevent it from exploding.  This venting of gases means the battery can't work as well or it might not work at all.  A slow charger usually charges a battery at 1/10 or less of it's rated capacity.  This is low enough that the battery can be charged indefinitely without getting too hot.  When a fast charger switches to the slow mode, it's at 1/10 or less of the capacity and this won't cause any heat problems.    

  

Answer 2

Usually rechargeable packs require a very long recharge time. Radios, phones, etc will have times from 6hrs to 12hrs depending on the run time of the battery.  

Answer 3

Can you not get Nickel-metal hydride (NiMH)

Nicad's have a 'memory effect' (not good)

maybe 6hours if its just trickle charging.

Does the charger not switch-off automatically.