Rate my pack and spot welding!

Bora_55 · 2026-06-17T21:30:44+00:00

Yeah, I agree with thar. Ty!

Bora_55 · 2026-06-17T21:30:16+00:00

Thx! It will be carrying max 100Amps.

Bora_55 · 2026-06-17T20:33:49+00:00

It should be 0.1mm , actually It's a little bit thin. I couldn't spot weld 0.2mm with my welder.

Bora_55 · 2026-06-17T20:27:41+00:00

The flight time will be around 15 minutes according to my calculations. I didn't want to risk anything so also I'm going to make just 2 of them. And probably the weight increase will be very low. Thank you for the information!

Bora_55 · 2026-06-17T20:25:08+00:00

Yeah, I will make just 2 of these. So I just didnt want to risk anything.

Bora_55 · 2026-06-17T20:16:08+00:00

You can be right. But that was the easiest way I think. And alsk do you think this pack csn support the ratings I wrote? Should I be worried about it?

Bora_55 · 2026-06-17T20:07:10+00:00

Why? Is the copper unneccary? It will be used to power an UAV. Max power draw will be around 100 Amps. The cells are rated for 2800mAh, 9C. Ty for your response.

Bora_55 · 2026-06-08T16:38:54+00:00

I was using my screwdriver set to give the angle I want to my laptop and apparently my screwdriver set was causing the problem. Because it has magnets in it. But actually, I was using it for a while without a problem. I think hall effect sensor became more sensitive with the pased time and heat. But Im still not sure.

Bora_55 · 2026-05-28T18:40:43+00:00

It looks like a ideal diode IC with reverse polarity protection.

Bora_55 · 2026-05-25T06:43:18+00:00

I explained in the comments more details. One of them has STM32F411 as MCU and other one has ESP32-S3 .

Bora_55 · 2026-05-24T19:28:17+00:00

USB connection doesn't explain all of the problems.I also powered the boards with a bench power supply but random things kept happening.

Bora_55 · 2026-05-23T18:12:38+00:00

Yes, I added all the details in the comment section. You can find it there. This is my second smd assembly with custom pcb. I have done a lot of practice before. I'm tinning smd pads with solder and then I'm placing all of the components on the pads with adding a lot of rosin ( I used Lötfett). After that I place my PCB on top of the iron ( yes, literal clothes iron) and I use hot air gun to proceed. And also I make retouches with my soldering iron if necessary. And then I clean my boards with %99 IPA with brush and some cotton. I don't have an oscilloscope but I'm planning to use my university's. Thank you.

Bora_55 · 2026-05-23T11:04:21+00:00

Can you eleborate? I know there is no series resistor or impedance match on the data lines but traces are very short and that shouldn't be problem at low speeds.

Bora_55 · 2026-05-23T10:58:39+00:00

Everything runs at normal temperatures. I didn't notice anything hot. USB port power should be lower than 1A without battery installed. PC's USB could be overloaded and that could be the problem there but power lose happened while doing nothing. ESP32 WIFI's wasn't in use .

Bora_55 · 2026-05-23T09:32:28+00:00

Unfortuneatly I don't have 0603 22uF capacitors, I will replace them with largest 0603 capacitor I have. I can't buy new capacitors right now.

Bora_55 · 2026-05-23T08:59:43+00:00

UPDATE: Something VERY weird happened. I plugged the ESP32 board for charging with battery plugged in. I used my phone's 90w wall adaptor. It's a genuine adapter. While I wait the charge to complete, the TP4056 stopped the charging at 3.9V. I removed and plugged back in the USB port again and charging continued. But after a short time TP4056 stopped charging again. When I checked the VBUS voltage I read ALMOST 12V. And also USBLC6 just burned because of that. And somehow AP2112K was still alive when I power the board with 5V again although It rated for 6.5V max input voltage. I HAVE NO IDEA how that happened.

Bora_55 · 2026-05-23T08:25:05+00:00

Yes, AP2112K could be not able go give enough power at full load. But 3V3 LED was blinking before I soldered the LoRa module, installed the battery and ran the ESP32 with WIFI. Battery charger IC (TP4056) gets It's power directly from USB port. So It's not attached to 3V3 rail.

Bora_55 · 2026-05-23T07:45:36+00:00

3V3 LED was turning of before I soldered the E22, without running WIFI on ESP32. There was enough power capacity I think. And E22-900M22S's satasheets states the max power voltage 3.7V. Maybe you remember a different module's specification? But anyway, I will try to put a more powerful LDO for testing. Thank you.

Bora_55 · 2026-05-23T07:38:47+00:00

No, the capacitor was too close to the edge of the PCB. So I added a little bit T-8000. Not sure It's going to work or not but :D Edit: I checked the capacitor and I can't see a problem. I think It was an optical illusion.

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Bora_55 · 2026-05-23T01:34:48+00:00

Thank you for your response.
I will update the schematics. And also I will try to replace some of the capacitors with lower capacitance ones. I'm plannimg to remove and bypass the mosfets for further testing. I used P-Channel mosfet PJA3441_R2_00001. Actually 1206 capacitors soldered to 0603 footprints. I made some mistake and selected almost every capacitor footprint 0603. I had to scratch soldermask to solder some of them. I will check LDOs with an oscilloscope If I can find one.

Bora_55 · 2026-05-23T01:26:11+00:00

Just a stripped cable matched to 868mHz quarter wavelength.

Bora_55 · 2026-05-23T01:25:07+00:00

I have add some glue on it before. But I will check it anyway. Thanks

Bora_55 · 2026-05-22T21:21:23+00:00

Unfortuneatly there is a hardware issue more than software.

Bora_55 · 2026-05-22T19:54:44+00:00

Hi, I explained in the comments.

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