Stobbie,
I have followed this thread since the beginning of it. I also bought one of the same power supplies as you did, but off Ebay. Mine took months to get here but it showed up about a week ago. China to the US, Florida to Central America and I got it. I'm really sorry for your loss as everyone else and very concerned because we are all looking for what really caused this. Many of things mentioned could have been the core cause and or a combination of them. I have my two cents worth as well.
Here is a pic of my power supply taken today. Did yours have the same color control box on it?
Image below from your Aliexpress link:
On Youtube there are many vids on how to mod this type and many other server power supplies. Most of us realize that the quality of parts used in many Chinese made or modded products are very poor, though not all. I have a lot of Chinese products that I'm very thankful to have.
In short this mod takes removing a resistor and adding a potentiometer and some replace one or more caps based upon voltage outputs.
For those of you that don't know this power supply from Aliexpress it has a nice display added to the top of it which shows amps and volts. There is a black dial which supposedly changes amperage on the bottom left side of the control box in this pic. On the bottom right is a potentiometer that is recessed and you can't see in my pic, but the Ali pic shows it. That one is for voltage.
Today I did basic testing of it on my bench. I have put up to a 22 amp load on it at 14.6 volts for about 10 min. The amperage adjustment does very little from what I have found though while adjusting my load testers and increasing the load the power supply kept up well.
Where am I going with this? I opened up the additional white control box. First thoughts was not bad and there are actual things inside that look like it really does something. I did not check the values of the potentiometer for wattage and resistance though I will if any of you feel it's needed. I opened the power supply as well though not fully because I would have had to un-solder multiple wires and I didn't have time. I can tell you that the solder work on the power supply side is very poor. Especially the only wire that goes to the left side of the power supply in this picture.
You mentioned multiple times you were pushing 30 amps at 13.6v during the charge. The power supply is rated at a max of 60 amps but only 12v. Yes that is only about 10% over but again the design was for 12v. Many of these power supplies can be pushed way over their rated voltages even to the point of damaging them. From what I read you then need to change the caps on that side of the circuit to be able to handle these higher voltages. This brings up the following point:
1. If the control box they add on to this unit has any issues with the resistance of that potentiometer it could possibly go a few or even many volts over your setting.
2. Check out what the seller says: (I copied this directly from Aliexpress)
a.
The first step: the charger should not be connected to the battery, turn on the power, adjust the voltage knob to adjust the voltage, refer to the voltage display above the display screen My comment: (this is the pot, not the knob and I'm sure you know that)
b. Adjust the current to a minimum. After connecting the battery, adjust the current from small to large and adjust to the current you need.
(In the charging process, it is not allowed to adjust the voltage knob again, otherwise overcharge or undercharge will occur)
That is a key point. It would appear that if you adjust the voltage after you have connected the battery the displayed voltage will no longer be correct and the output voltage could be higher than what is displayed. This makes perfect sense. The power supply is set at a voltage and though you adjust it higher or lower you may not see the change due to caps and the circuit design or a few other variables.
I tested this theory but only for a few minutes and did not come up with anything conclusive. But it makes you wonder why both the seller on Ali and Ebay mention the same thing.
I feel these are extremely low cost high output power supplies that are being used for something other than their initial design and the workmanship is horrible. From what I see this could easily have been another possible option which caused something to go wrong.
Can these be trusted? I will trust them but only with a high voltage disconnect relay / solenoid so in the event it decides to go over voltage the device will be disconnected from AC.
If any of you have anything further that you would like tested let me know. Stobbie, same goes to you. I would be happy to run tests. And, I surely don't recommend 50 amps on these due to higher voltages in turn you exceed max wattage output or close to it.
If I'm all wrong in this evaluation or completely missed something, well I tried.