ija

If you test every unit for 5 seconds it's not enough. How about doing some stress test for 20 units or so? Turn on/off every 10 minutes for a week and move gears maybe every 1 minute? This is very easy to automate. I'm rather sure atleast some of those will fail similar way as mine did and it's not going to take a week. Difficulty is that there will be several fail mechanism and the critical one is FET control, and you need to have both FET controls to fail same time. If something else fails, eg watchdog mechanism may be able to keep the system sane from user point of view even bad things happens behind the scenes. Please ask Erwin to discuss to someone with real professional experience on high speed electronics and he/she will explain Erwin why it's not ok to use voltages beyond operational specifications. It really seems to me that Erwin is not able to understand whole thing and the fact that this controller is causing unnecessary risk to everyone; this risk is easy to eliminate: instruct everyone to use low 5-5.5 voltage or/and fix the controller.

I just had "bad" luck and it failed immediately. And my thinking is that I can not be the only lottery winner with this system. (or actually it was good luck because if it happened on the flight it could have been total disaster. It was also good luck that I had so bad warranty service from Erwin: If he had taken care of warranty normal way I would newer have checked failure mechanism but thought it was just single bad unit. If you all have good experience then it might be that I would have newer experienced the problem again but someone else would have crashed. And... Is there several batches? Maybe you have older version with 5.1V zener but mine has 6.2V zener by manufacturing mistake? Then all with new gear are really in danger? Have Erwin checked this option?

Also Erwin "knew that I used 3S" as an immediate response... my guess is that this happens rather often. I don't believe all of those were so stupid that they really used 3S!

Very clearly Microchip PIC works somehow even with 6.25V because testing has been succesful. But it's not reliable with such a voltage because if it was then Microchip would surely rate it for higher voltage. Controller may fail every now and then and reboot itself but noone notice, or IOs may fluctuate somehow but not enough to always cause visible troubles. BUT for me it caused a problem: either firmware execution got corrupted or/and IO cell failed so that it forced FETs in short circuit. Of course there could be other failure mechanisms also but this sounds very potential to me because of the very clear design/manufacturing error.

Full A123 voltage is too high also but sure regulating down is an option; 5...5.5V target probably the most safest ones with this. But Erwin has stated that I have no warranty because he claims that "He knows I used 3S" and therefore I should pay him more to get replacement PCB. It's cheaper for me to create new solution and then I can freely use 2S LiPo without worries. (and I like building gadgets so this is not a really too big hurdle for me..)

(And if there was working controller PCBs on hand it's much easier to swap the zener on the PCB to 5.1V or so - no need for external regulators. even though zener-shunt solution is bad as such...). Erwin could save a lot headache just by updating this one component if he is not willing to do it properly with a linear regulator.)

Regards,
Ilkka