RE: Charging NiMH batteries?
The short answer is yes, the Futaba charger works OK. Like most shot answers, there is a BUT included. I have fried a couple NiMH batterys by over chargeing them. With the last batterys I bought, there came with a warning about not leaving them on a trickle charge as they would overcharge. SO, if your battery is discharged, and you are charging at a rate of 100mah, then your battery would need 20 hours of charge time. Big IF though. You flew today for a total of 30 minutes flight time. Your system draws down about 400 MAH, so you have consumed 1200MAH of the battery. If you put it on the charger over night, say for a 10 hour charge, you are going to pump in 1000 mah. OK 12 hours would peak you up again. However leaving in on the charger longer is going to cause the battery to overheat and break down. The biggest problem is that the charger doesn't know the condition of the battery, it just pumps out 100mah until you unplug it. And, you don't know the real condition so you can accuratly time the charge required.
What is really needed is a peak charger and even then they can over heat, over charge a battery at times. I have ended up using my field quick charger for any charging on my NiMh batteries, but I don't peak them after the first cutoff. Some chargers like the AcuCycle Elite have a thermal sensor to detect when the pack is at maximum. At first I kind of skoffed at this, but after about loosing a plane because an overcharged TX battery suddenly dropped to 8V a few minutes into is first flight, I'm changing my mind. $150 to $200 sounds like a lot for a battery charger, until your $800 plane goes into the swamp, never to be seen again.
My TX's give an accurate voltage reading, so I know when I'm down to 10V, I can do an overnight charge with out problems. My reciver batteries are all NiCd for now, all at 1000mah rating. I can wear myself out flying for a day and I can leave them on the wall wart for a couple days without damage.
Just some stuff for you to mull over.
Don