You may have developed a "memory" in your rechargeable pack. Even though modern rechargable battery technology is supposed to have solved the "memory" problem of yesteryear's nicads, it is still there to some degree. It works like this: If you hunt for 45 min. to 1 hr, then go home and throw your pack on the charger before it was fully discharged, and do that time after time after time, always recharging it after 45 min. to 1 hr, then eventually, your pack developes a "memory" to be fully discharged at 45 min. to 1 hr. That's why it's best to use them till their all the way empty, before charging them. Even if that means having a spare pack in your apron to switch to in the field. I know it's hard to know you're going out with a 1/4 charged pack. The temptation to "give it a boost" is strong. But eventually you'll only shorten the batteries life, if you don't let them drain out all the way.
Also, a lot of nicad rechargeable packs have instructions to "charge after each use" (like walk-around phones, for instance). So some people will beg to differ with my advice, and say that the instructions don't say anything about that, and that they say to keep returning to the charging cradle. All I can say to that is, I bet it's so they can keep selling you lots of recharge packs! I ignore those instructions, and run them all the way down before charging. I get years and years off packs, even with constant use by doing this.
