LiPo Discharger - Resistor Load Bank - Build One Quick and Easy  

Nice mods. Glad to hear this solution is being used out there :)

That was one step along the way. It has an integrated cutoff circuit now.

Awesome! Knowledge is power. Glad the video helped you make a choice. Thanks for checking-in.

Glad it was helpful!

Not sure I follow your question. Any conductive metal can be used to make electrical connections. Some have different properties than others, but if they conduct electricity...

@@RCVideoReviews Hello, yeahh...I bought some steal rods with the right diameter. It should do the trick. Thanks.

Sounds like a good setup. I had fun putting this together too.

I don't recall. It probably seemed like a good idea at the time.

Thank you! Glad to help.

Anything is an option. Do what works for you.

Thanks 👍

Not too long ago, my hosting provider somehow lost all the files I've shared over time. I just re-posted it and verified the link in the description.

There's a little bit of effort to make it interesting. Can't be a robot about everything. It's not high school science.

Thanks for the tip :)

Use it twist by hand, not in the power drill, those bigger bits get hungry and want to eat though wherever they get a chance! lol

You're welcome. Hope you can use it...

I'm very happy to have a competent discharger. I still use this very device every time I fly. Thanks for watching.

No, that's RU-vid enforcing an https requirement. I updated the link. It works now. Glad the video helped you out.

Not the way it sits. The best option right now is to attach a low voltage alarm. They’re available just about everywhere for a few dollars. Set it to 3.7 and disconnect when the alarm goes off. We’re working on an auto cutoff now and have the basic circuit worked out.

Thanks, I do have one of those. Do you have the brand/ stock # of balance board you are using your battery charger?

@@rpmspeedyblue The balance board I used in the field box is from GetFPV: www.getfpv.com/jst-xh-balance-board.html If you're referring to the parallel boards in some of my videos: www.amazon.com/Battery-Charger-Parallel-Balanced-Charging/dp/B07SQ8BWDD/

Thanks for the info, much appreciated 👍

You're welcome. FYI: I should have all the parts I need in the next day or two for the automatic cutoff. I'm excited to add that feature to the discharger. I've also been running the discharger quite a bit over the last couple of days--kind of like sea trials. It has done very very well. It took a fully charged 6s pack down without any issues although the heat sink was warm. It knocks down 3s and 4s without breaking a sweat. It is REALLY nice having a nearly silent ~1c discharger for 2200 3s/4s packs. I LOVE this thing. I'm probably going to make another one as a standalone (bench) device.

It's about 6 years old. Not available on the market any more.

Yes. I added it. FYI: If you look at the formulas in C24, C25...C28 you can see what I did. I just multiply peak voltage (4.2) times the number of cells in that row. So you can add whatever number of cells you want by just copying the row and editing that one value.

That would be cool, but for my field box, this little setup is just perfect.

I wanted the configuration to support 3s-6s. This configuration allowed the maximum wattage of the network to stay below the rating on the resistors I was able to get for any battery I use on the discharger. Also, remember, this was designed to go into my field charging box (which it did). My intended us is to take a used flight pack (say 3.9x) down to 3.80. This design allows all packs from 3s to 6s discharge at approximately 1c without exceeding watt rating of the network and it allows me to manage the impressive amount of heat created during discharge. I have a resistor calculator available for anyone who wants to just plug in different values to get an overall picture of overall resistance/amps/watts using both parallel and series configurations. One other benefit of series v parallel: In a series configuration if a resistor breaks, the circuit is open and stops working. In a parallel configuration if a resistor breaks the circuit remains closed and current flows over the remaining resistor which--in my use case--could create additional damage to the box. So the series design also acts as a sort of fuse if there is a resistor failure. FWIW This resistor works perfectly for my use case. I've put it to work on numerous occasions and I'm thrilled with its performance.

You're welcome. FYI: I use that discharger to this day in my field box. Works well.

@@RCVideoReviews I just wanted to tell you, I just finished construction of my discharger! I used the exact same heatsink and resistors, a slightly diff voltage stepdown (the kind that has a voltage output readout) and a similar PC fan that's a little bigger than the heatsink running at 13.4 volts. I'm gonna mount the sink to a piece of wood since it's gets pretty toasty, but it's working great so far!! I'm using my ISDT battery checker as the low voltage alarm ( I watched your video on that one, and that was such an excellent video I went and purchased one!!) Once again, thank you for your electrical chart and thank you for producing such an easy to understand and follow video!! I really enjoyed putting the project together! When I finalize it's final form, could I email you a picture of it? I just want to pay homage to the original creator of this contraption 👏

Sure! I’m always happy to see people benefit from my projects. Definitely fire away.

Two fans in, one fan out. One fan on the back of the power supply blows in, one on each end of the case. The left side blows in, right side blows out.

@@RCVideoReviews Ah-Ha Now that I was back checking out what you said, as soon as I looked I caught sight of the fan on the left in the handle recess then I saw the other side. Very good sorry I missed it, I knew you were smart enough to do that just wondered why you didn't mention it. Good job, I just pulled an old Firefox RC CAR NiCad Discharge box from the racing days in the 80's. Don't remember how many 12-volt auto light bulbs are in it (riveted closed) but has 4 switches to increase the amp draw for a faster discharge rate. I'll have to pull it apart to check it out for possible use like your resistors set up. Thanks for the reply.

These amzn.to/32ezKfE

They're really easy. Just watch the heat.

@@RCVideoReviews Yes. I will put two heatsink and fans top and bottom on resistors. and use it lying side

@@RCVideoReviews I use big batteries 4 to 8 7000mAh. I look for a 15A discharge. Do you think to build this is buy more powerful resistors and pay attention to cooling?

I just checked and it worked ok for me: rcvideoreviews.com/rcvr-rcalc-v2.xlsx

@@RCVideoReviews Thank you. Tinkered a bit and it works if i copy the url and paste it in a new tab. Very strange.

@@Fumes74 I've had some weird issues with RU-vid redirects in Chrome. Oddly they all work in Edge and Safari. So good job Google?? I guess??

V=IR If you know the voltage and the resistance, you can calculate the current.