ESC and PDB Question

Hardware Multirotors
1

Hello
I’m putting together a Quad copter. I Just received my PDB and ESC’s today. The soldering work is pretty straight forward. Soldered the ESC’s + and - around the edges of the PDB and the battery leads.

I inspected my soldering work and saw no traces soldered together or any + and - misplaced on ESC’s. I thought I would check the UBEC output voltage with out motors or APM hooked up, just the ESC’s and the battery.
When I plugged the battery into the connector wired to the PDB, it arched from the leads “scared me a little” and I immediately unplugged it. Fearing I had a short I checked the battery leads going into the PDB and found there was a fairly high Ohm reading but not a direct short. Is that normal because of the ESC’s or could one of them be bad? I have all the leads to the motors covered separately so I’m sure that’s not a problem and Short of unsoldering each ESC, I can’ read the Ohm’s individually
If the Ohm reading is normal because of the ESC is the arching also normal when plugging in the battery?
Using 30A ESC, Simple PDB and 11.1v LIPO 5200mah

Thanks in advance
Rod

2

Just as an update, I unsoldered the Pos leads to each ESC and the Ohm reading was 13.87K on each one. I also measured across the +&- leads on the PDB and no ohms were read.
I re-soldered it all and plugged in the battery, once again it arched but I left it plugged in for a few seconds and I didn’t feel any heat in the battery or wires. I’m assuming all this is normal.
I would still like to hear someone else say "yup that’s normal :slight_smile:"
Rod

3

@novoid,
If nothing is getting really hot and does appear to be overheating, then the arc you are seeing is the ESC capacitors drawing charging current when you connect to the battery.
Regards,
TCIII GM

4

@TCIII

Thank you for replying
I left the battery plugged in for approx 30 min and every thing was still cool.
You must be right, it’s just the cap’s charging or something similar.
Thank you again.