any good suggestion?
someone said the battery charged by this is more punch than the other.

Only way I could see that is if some one was charging over 1c and it warmed the packs up.

Only real reason to go with a DC power supply is, you can get more powerful units, and you have a wider selection.

i have the 100A power supply

people are discharging at 20amps, then charging at 40 amps to warm the pack just before the race, thus lowering the IR and increasing the punch.

discharging at 20amps i need to hook up a lead battery by using Regenerative discharge, right?
does this charger charge the battery gives the same punch as most rc chargers like hyperion, LRP,......?

the charger does not increase the punch, per say. Its the warming of the pack. Most guys are using the icharger 4010 for this. It will discharge a 2s at about 20 amps and can charge a 2s at 40amp as well.

I should say in this way. Some claimed using some brand of charger, the battery is felt more power than the other brand. Are you bros having the same feeling of different "punch" by different charger with the same piece of battery

no

Doing this this is illegal per ROAR. Maximum charge rate is 1C.

Check section 8.3.2.5.3

http://www.roarracing.com/downloads/..._Rule_Book.pdf

Also, 8.3.2.5.4 states, "Maximum temperature for a charged li-poly battery pack shall be ambient temperature +/- 5 deg."

I dont do roar races...

Does this not negatively affect the lipo in some way? At least shorten its lifespan I would think....and charging at a rate of roughly 8C is actually a little scary. Highest I've seen is a Nanotech with a highest recommended charge rate of 5C.

Do these guys discharge them very low because at 40 amps, I imagine it doesnt take long to get to 4.2V/cell even if the lipo started at 3.0V.

rhe packs life is great shortened. they are sponsored, so they dont care about packs lasting forever.

I don't believe they discharge to 3V/cell, more like 3.4V or higher. Regularly discharging to 3V might be as hard or harder on recent lipos as the higher rate charging.

i am pretty sure the discharge to like 3.6-3.7 just under storage. otherwise, the packs get pretty warm