hi

whats the difference between the two different methods

Discharge utilizes the internal circuitry of the charger (resistors) to discharge the battery. You are typically pretty power limited in this case. Regenerative discharge allows you to basically convert the discharge power from a battery into charging power to another battery in a dual port charger or back through the power input to a supply battery. This method typically allows for much higher discharge rates versus using the internal circuitry. On a dual port charger, regenerative discharging can also allow for the use of a large resistor in place of a second battery to absorb the power of the battery being discharged.

So you can only use regenerative discharge is charging off a battery not a power supply

Depends on the charger. On iCharger DUOs you can discharge from one port through the second port to either another battery or a large resistor. On single port chargers that is how regenerative discharging works - you are wasting the discharged energy back into the power supply, which must be a battery capable of absorbing it. On single port ichargers you can also do a discharge+ discharge, which allows you to run a resistor bank inline with your charge leads to boost discharging capability, no matter what is on the power supply side of the charger.

I have the new orca and will be chargeing initially off my power supply

Not familiar with it and cannot find a manual online for it yet.

You may be able to make a simple stand alone discharger and use your charger's balance leads as a monitor/alarm for end-voltage. Would need to see a manual to know what is possible.

What is this method useful for? Just wondering... is it just to leave your packs at a specifically discharged state or?

Two uses. Either running your batteries down at the end of a race day to storage levels. Sometimes the built-in discharging can take quite a while, especially if you are limited to around 30 watts of internal discharge capacity. The other thing people use high-amp discharging for is to quickly deplete a battery between races so they can then hit it with a lot of charging amps in an effort to heat the battery up and lower the internal resistance.

I use it as an occasional health monitor of my batteries. Charge them fully and run a high amp discharge program to check IR and voltage levels at 1 minute, 2 minutes, 4 minutes and 8 minutes.

Ahh ok, thanks for the clarification. Do lipos run better when "hot"? To me that seems like a possibly dangerous and costly situation to put yourself in..

I would call it warm, not hot. Yes, they typically drop IR (internal resistance) as they heat up which allows the voltage to hold up better over the course of a race. It's a "thing" in many stock/spec classes to give that little extra edge.

You will hear widely varying concerns for this activity from :"no big deal the batteries can handle it" to "you are going to blow yourself, the entire facility and all other participants up."

LiPo explosions are scary and happen fast. If you are going to charge at higher amp rates always have them in a LiPo bag.
I highly recommend balance discharging for 2s or more. I believe that your batteries will run better longer if you do. I personally use a iCharger 4010 because of its ability to do that. It will discharge a 2s at 17a while balancing. Something like 140w/channel of discharge capability. Worth the money.

Is it necessary to use the resistance bank?
What benefit does it have for the battery?
is it good to download so fast?
a greeting

The 4010 will handle 17a on a 2s without the external resistors. You can go higher with external resistors.

what about Synchronous Mode in the 406 manual on page 11 it shows that it would allow i think 70amp charge and discharge setting it up this way would it not do it all internally?
I have not tried this I just noticed it one day and have been meaning to look into it more, sure it takes it down to a 1 channel charger but so does using the external discharge bank if I am correct . it looks like all you would need to do is make a new set of leads if anyone has tried this or knows about this please tell us about it

I am not saying anyone needs to charge and discharge at 70amps, I am just saying its shows that as its max and if so it shouldn't have any issues doing a 15amp charge 40amp discharge cycle to test some packs

I would have to take a dive into the manual to be sure but my recollection is...
Synchronus mode discharge is capable of 140 watts. With a 2s battery that is roughly 17 - 18 amps discharge.