Originally Posted by Jack2
Thats a pretty wide open question. The very short answer is, NiCd batteries are older technolodgy, NiMH are newer and are better in pretty much every way. They don't have the bad memory problem like the NiCd's do.
NiMh cells have come a really long way over the last few years too. They keep getting bigger and better.
The "Memory" problem with Nicads is basically a myth. The idea of the memory problem arose from the use of Nicad batteries on board sattelites that charged via solar panels. During certain parts of their obits the batts would only receive say 80% charge, then discharge to 20% capacity, and so forth for a certain period of time. When their orbits were slightly different, the batts wouldn't charge past 80%.
Using NiCad's for RC, the memory situation never would really come into play for the simple fact that the batts were basically used up, as in they were charge so heavily and discharged so heavily that thier lifespan was so shortened by that abuse that they never had a significant amount of time to develop a memory.
However, NiMh do not seem to exhibit this trait anyway, if it was ever a situation with RC.
To answer the other question, is a Nimh 3300 better than a NiCad 2400, the answer is simply YES!!! Their voltage output is FAR beyond that of any nicad ever in use for the RC application its not even funny!!!
And now with the introduction of the Intellect IB3800 cell, they are seeing voltageages of 1.2 volts average on a 35 amp discharge. A Nicad 2400 (sanyo for instance) at a 35 amp discharge would be something like 1.12 volts. For a whole pack thats .36 volts difference. That is very substantial. The average 3300 (GP) produces better that 1.17 (at 30 amps), which is still .35 volts per pack (6 cell) more than their 2400 nicad counter part. *Note the 2400's in question were probably matched at 30 amps to get somewhere around 1.16 volts per cell, and and IB3800 at 30 amps could be as high as 1.21- still about a third volt better per pack.
In short, the Nimh technology is far better for capacity and voltage than Nicad.