Since I had a set of batteries survive 10 years... never cycled ONCE... the cycler is obviously not a necessity.

The primary purpose of a cycler really is to measure the current capacity of the battery. This is a test to see if the battery is in the early stages of failure. The cycler can definitively test and find a 5% loss of capacity.

You will find that capacity varies with the temperature of the battery. (kind of interresting to play with this. ) And capacity will vary with usage of the pack. The first cycle of a brand new, never before charged NiCd will be short. A couple of charges later will be your maxmum, then it will begine a very slow decline. (nearly a flat line for a long time) Colder means more capacity up to a point. Hotter is just too dangerous to play with. (NiCds can explode if too hot) Taking a battery that was charged when warm and then cooling it... you will see a marked reduction in what you can get out of it.

An annual or semiannual cycling test program is a good idea. (you'll know your battieries' conditions) Monthly cycling of NiCds that are not being used (when you put the airplane up fr the wnter) s a good dea too. NiCds that are not used tend to go bad faster.

The battery clinic site tells more... and better detail. This just works.