Well i charge mine for 2 hours. For me the battery was in an airsoft gun magazine when i was younger. I remember that i over charged it and it broke so i wouldnt go over 2 hours. hope that helps.
Rf80-k aircrfat battery charger can charge all type of batteries dry and wet cells
NiMh is usually considered the most direct replacement of NiCd.
Yes, as long as you use an NiCd charger, but you really shouldn't. NiMh has twice the capacity of NiCd and it is less expensive. NiMh also contains no toxic materials so it is better for the environment.
You could replace it with a battery with a higher mAh rating and the battery would last longer between charges. Increasing the voltage (V) may lead to better performance, but it could severely damage the electronics. I would highly recommend NOT increasing the voltage. You could get more than twice the lifetime with an NiMh battery instead of an NiCd. You will need an NiMh compatible charger. I would highly recommend NiMh over NiCd.
Probably, but they may come out slightly undercharged.. I've put NiMH cells in a charger designed for NiCd without a problem but haven't tried the other way around.
Can be just about anything, from a small button battery for a small LED, to NiCd to Li-Po.
1.5 volts if you have an alkaline battery. 1.2 volts for most rechargeables (Li, NiMH, NiCd)
If you are talking about a zinc carbon battery, 1.5 VDC. A NiCd has 1.2 VDC.
Some will, but it is not recommended because it can damage the batteries or the charger. Invest in a NiCd charger or better yet get some NiMh batteries. NiMh batteries are better than NiCd in every way.
NiCd, Lithium, Lood, NiMH, Li-ion, Alkaline. I can't tell you which types are appropriate for your medical device(s), anyway! (NiCd and Lithium battery types must be disposed off properly).