What’s the expected lifetime of NiMH packs vs Nicad packs?
Not all cells are created ‘equal’ There are a number of suppliers in the market providing NiMH and Nicad packs for very inexpensive prices. Most of these cells are Chinese in origin and the standards of manufacture can be pretty dismal resulting in poor performance under load, poor reliability and significantly reduced duty cycle lifetimes. You need to know what you are buying if your concerned about quality AND price. Overall, comparable quality NiMH and Nicad cells offer essentially the same life expectancy in the hobby enviornment (2-3 seasons; sometimes less for ultra hi-capacity AA systems). I recommend you use only high quality cells from reputable manufacturers in R/C applications and replace your packs every two to three years regardless of whether you use Nicad or NiMH.