Never mind worrying about trickle or not to trickle, worry about using that dangerous timer charger. You can not get todays Nihm or Nicad packs charged in 30 minutes at the low amp rate they run at. So your forced to keep cranking the timer and then you enter the danger zone of no peak detection!! 1 or 2 minutes to long and pooof your pack is toast.
Do your self a favour:Get a peak chargers before you spend another dime on this hobby, you will get better runtime,voltage out of your packs and you will protect your health and safety knowing your pack will stop charging when it should, not to mention the safety of your home..
I really think the RC industry and hobby shops should ban the sale and use of those chargers. ITs only a step above pluggin the packs directly to a 12volt car battery.
Sorry for the rant..
Turn off trickle charge if you can, its only usefull on transmitter batteries that require low charge rates
"Without Rules its just Backyard Bashing!"