Are you planning on mounting the gold heatsink on top of the black one? That won't provide very good cooling of the black heatsink. There's too little contact between them. Get a good 80mm or 2 x 40mm fans. More airflow over the heatsink and lower noise.

Originally, I bought the fans and then I bought the heatsink thinking I would mount the resistors on one side (flat side) and the fans on both sides making a sandwich. Once I got it, I decided that the 4 heatsink fans wouldn't be good because of exactly what you mentioned. I think I am going to get to 2- 60 or 70 mm fans for the fin side and I'll run two heatsink fans on the tops of the resistors where I can put some thermal paste. I just wanted to make sure the wide heatsink wasn't going to be an issue. with wiring, etc.

some aspiring electronics guy should look into how a solar battery charger controller works.

Why and what has that to do with this topic?

Isn’t this thread titled Discharge Bank Build? I thought you were a proponent of not feeding people the answer. I’ll give you a clue but nothing more. You’ll have to be aspired or not, you certainly have the electronic guy part.

think about the direction current flows through a solar charger under all the conditions its exposed to and what does it mean to be a controller of that.

Ah, because of that diode sugestion of no need to switch cables, that will not work..... I could not understand the link of your rermark with this topic.

Well if you want to go advanced I sugest to use a hall current sensor that works in both ways (they are very cheap to find). Then you can make a detector in which way the current flows that controls a relay that will switch the resistor.

https://nl.aliexpress.com/item/32995196340.html

Use a battery and a BMS.

Question on the resistor bank. Order my 5 1ohm resistors and they are all about 1.2-1.25. So, my bank is going to be about .25ohm. My math says that only gets me to 32 amps at 8v. If I add another resister or two to drop the resistance down to .2 or less, will the icharger then limit the current to whatever the setting is (40a)?

Yes, if its a duo. The duo's regulate output voltage to get the desired wattage/amp draw. The X6/X8s have to be pretty exact from what I've seen.

Thanks. That makes sense considering how they work. I guess I'll order an extra resistor or two. The homebuilt one can be for the duo and the other one made "professionally" can be for the X6.

Hi, i have an Icharger 406 duo and i would like to build (or buy) a bank resistors of 40A for Lipo 2S 7.4v / 7.6v, i have read the whole discussion and everything is quite clear, but since i understand a little bit of current and soldering, i am a pure neophyte to these things of resistors, Ohm and the rest, so i would like to ask you all a favor, and that is if it is possible to have a list of the pieces needed so that i can buy them all together and then maybe a nice drawing or better a scheme of how to assemble everything .... It would be a beautiful thing so i could easily have fun assembling everything, since it has also become almost impossible to find them for sale at acceptable prices .....
I thank you all in advance, even if only for what you have already described.
Byeeeee ;)

I know this video, is for configuring the Icharger and the resistor bank, but i need some video to build it.....

I don't have a video to build them. They are super easy once you assemble the parts which can all be had online. There is a fair amount of variability in the components which can be used. And, when it is all said and done, it's still $20-30 USD in components.

You can see in the video how the wiring is. In the video posted, the unit has the resistors glued to the heatsinks built into the fans. That's the most cost effective way to do it. All your resistors will be arranged like railroad ties under railroad tracks. Envision the tracks being your copper wires connecting them all together.

You'll need the resistors. 100W 1 ohm is I think what you need if I remember correctly.
The fans I bought off ebay and amazon. I used a combination of fans built into heatsinks and plain fans to create the unit I wanted.
I opted to add a heatsink to mount the resistors too for more cooling and more stability. Added about $12USD to the project.
You'll need thermal adhesive to glue the resistors to the heatsinks.
Copper wire to make the connections. I used solid for the resistor connections and stranded for the leads.
Banana plugs to connect to the icharger and banana plugs to connect to the power supply to power the fans. I power my fans separately.

Arrange the resistors on the heatsink how you want them. Apply a thin layer of thermal adhesive to each one, place it and press down. By adding the extra heatsink plate, it made gluing the resistors down easy.
Now, run your copper wire from each resistor to the next one. You'll run a strip up each side so they are connected in parallel. Solder on your connector leads. Add your fans either by screwing them to the heatsink or gluing them to the resistors, etc. I prefer 4 fans, 2 blowing on top of the heatsink and 2 blowing on top of the resistors.

Wire your fans (make sure they are 12v fans)

ok, i try to do it, only another question, can you say me the correct connection between icharger-discherger-battery?