This ain't exactly a home construction question, but it does involve the use of the Ni-Cd batteries used in tools. I've had trouble finding a forum on the Web that might answer this...
I just bought a Radio Shack scanner that uses a pack of four AA Ni-Cds for power. To charge the pack, you turn the scanner off and plugin the AC/DC 9-volt "wall wart." Seems simple. However, the chart in the owner's manual only provides two suggested charge scenarios:
Current Charge Time
600 mAh 6 hours
850 mAh 8 hours
That's not real helpful to me, because the only information I have are the wall wart specs saying its output is 1 amp (1,000 ma). It's confusing, because their chart suggests it takes longer to charge the Ni-Cds if more current is being pumped into them. I found an online calculator that suggested I charge for 3 hours at 1 amp, but my research says it's bad to charge Ni-Cds quickly. What do I do; put a resistor between the charger and the battery pack so that it will trickle charge?