Never completely discharge a Nicad! I've always found enough capacity in my battery packs to fly for around 1 1/2 hours, after being freshly-fully charged. This is an average time and not written in blood. Piper has given you good advice!

Nicads can develop what is termed "memory". This might happen if like you say, you consistently fly 3 ten minute flights and re-charge. The battery develops a memory and will develop a memory allowing a discharge of 30 only minutes.

It is very good for Nicads to be "Cycled". Cycling is discharging down to a specific voltage and recharged to their maximum capacity. I used to have a unit called a Super Cycle. It would discharge the 4.8 volt receiver pack and 9.6 volt transmitter pack down to a specific voltage and keep track of how long this discharge time lasted. Then the Super Cycle would flip to charge and charge the packs back to maximum capacity. I now have a unit called a Sure Cycle built by Hanger 9. This unit discharges and recharges, but, does not keep track of time. Instead it keeps track of the amount of milliamps used and keeps track of the charge time. I wish I would have held onto my Super Cycle!

Does anyone know of a cycler which keeps track of discharge time?