I heard brand new battery pack is not powerfull as that pack after few time charge, is that right? and how difference between them, i mean.. alot or i wont notice.

when you first run them, they need to be run in a few times before they put out full power

is it big difference?

not too big, but there will be a noticable increase in speed and power once you have run the batts a few times

An other thing you can do : discharge and charge them a few times before first use.
Thing I always do with my new batts is first give them a slow charge, then a discharge and a quick charge.
Then there already full power

i find it better to discharge them the old fashion way....in the boat...youll have alot more fun than sitting down watching tv waiting for it to be finished discharging....

The chemicals in the Batt need to be "Reved up" in order to make the Batts perform at their Best..

A Charge of 3 amps is cool for its First charge, then go and run it in the Boat being mindful that your Batts run time may only be a few minutes..
Run the Batt till there is a performance drop then Bring it in, take it home and Discharge it on your Discharger (a Triton Charger is good for this) Then rip 5 amps into them and all will be sweet.

i thought it wasnt good to discharge nimh all the way.....

that what i thought too, and i never discharge my Nimh all the way, but its just me

Most Dischargers Cut the Voltage at 4.8V although I have heard of people Discharging Intellects to 0.9V
Then Ripping them at 6amps.

too bad my Charger only charges at 5amps

.9v PER CELL!!!! Not per pack. If you do that per pack you'll ruin it. For example a 6 cell pack would be 6 X .9 = 5.4v.

But, you don't need to discharge nimh anyway....isn't that one of the main benefits of nimh in the first place? If you're cycling the batteries that's different, but they don't need to be discharged for normal maintanance.

that's thru I only do it for cycling , to rev them up after a long time no use or new ones.
Another weird I 'm reading here is that you'll put 6A in Nimh!
That's for sure hell and ruin garantied ! ! ! The load capacity of such cells is 1c !
Wach Gp website so if you're using 3.7packs charge them at max 3.7A.
That's the disadvantage of Nimh , nicad you can pump in the double of there capacity but Nimh's not.
The other and good thing is that they don't have a big so called memery effect, and you don't need to discharge them.