I just had it opened back up, all the way up, took a bunch of photos of the caps and the bottom of the circuit board. Have not yet put them on laptop.
I measured the resistance of the Pot.
2 of the 3 legs are joined on the bottom of the circuit board.
With my DMM set to K ohms, and the voltage Pot dialed fully CCW to the minimum voltage: 0.872
With the voltage pot dialed fully CW, set for maximum voltage: 0.000 k ohm.
When tracing the path of the voltage pot it goes to another resistor a few inches away which measured 1.258 K ohm and continues on some untraced( by me) path beyond that.
So it appears that having a higher resistance pot would only allow lower voltages to be dialed in.
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The 3 smaller blue Caps read LXZ 16v 3300 uF
The 2 large Purplish caps read
Sunny DZ
CE
200V 680uF(M)
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I pulled the aftermarket Noctua nf-a6x25flx fan off my Schumacher and tested it side by side with the Long chang fan provided with the MWclone. The Long chang fan pulls 0.18 amps @12.4v and vibrates. The fan is about half as loud in free air compared to when mounted in the case.
It moves more air than the Noctua.
The Noctua measured 0.10a @12.4v and was almost silent but moves ~ 2/3 the air of the long Chang.
When I put both fans upto the clone lid's restrictive case opening the Noctua was still quiet where the longcheng got a lot louder. The longchang was still able to push more air through the restriction, however the airflow on both fans was cut by ~2/3 compared to the fans in free air.
No doubt just cutting a 80Mm circle through the case will vastly increase airflow and reduce noise, but exposing the fan blades might allow things to fall inside if mounted flat on a table or such. Mine will be mounted on my cabinet door, the fan vertical.
I know a bunch of you have no concerns about fan noise, but it is an issue for me. I've mounted the Noctua 25mm thick fan to the outside of the case, but still need to cut the 80mm hole tomorrow. With the restriction removed and the Noctua fan mounted externally, it will move more air through the unit than the longcheng fan inside and restricted. The noctua will not fit inside the case, it is too thick by about 5 MM.
There are blobs of white thermal grease at the base of the caps. I'm not sure if this is purposeful, or just dropped grease. I am not sure what the electrical components are called which get hot and transfer heat to the case. They have a bunch of this white grease, then some type of flexible barrier which is pressed against a 5mm thick aluminum plate, which is attached to the case. A longer machine screw goes from the outside of the case through the AL block and grabs the "thermistors?" and pulls them tight to the barrier fabric and aluminum plate, and case.
The 5mm thick aluminum is not a perfect fit to the case. A strong light reveals small gaps no matter how tight i get the screws, and being aluminum, I am not torquing them too much. I was thinking, after I am done with my tinkering, about borrowing some of this thermal grease globs from the bottom of the caps and spread it between aluminum plate and casing to fill the small gap and aid heat transfer to it.
I put the longcheng fan on the Schumacher sc2500a. It will be relegated to portable/ backup duty. That charger needed to be monitored too as it would shoot into the mid 16's on occasion, so this manual PSU is actually safer.
One strange observation is that the GT power meter, when on the schumacher at 25 amps, the voltage reads 0.5 to .6 higher than my battery monitor.
The gt meter on the MW clone at 37 amps is within 0.15v of the battery monitor.
Not sure why this is.
