Definite Improvement.
Good job!
What CFM rating is that fan? It is great you opened up the mounting brackets and exposed the casing in that area to airflow and convection currents.
Surely the unit will last longer for the increased airflow though casing and likely never shut down to thermal overloading, but one should take comfort that the MeanWell has thermal protections built in, and being power factor corrected generates less heat than a Non power factor corrected charger.
The following is thought for further improvement, not criticisms. Nor required to keep using it as is..
These fans are very negtively affected by resistance/ objects that are too close to the spinning fan blade, especially objects behind the fan. Since you do not apparently have space restrictions, mounting the fan a but further away from resistance will greatly improve the fans flow, and reduce the noise it makes. Do you have another fan that has failed whose guts you can remove to extend it 1 inch further away from case lid? This would be simpler than making an extension.
In the following photo. One can see the transistors on both left and right sides of the inner case. They generate a lot of heat and are electrically separated from the casing, but use it as a Heatsink. They use some silicone thermal pads, designed to stop electrical flow but maximize heat transfer.
To further assist the heat transfer they use thermal grease. I found mine not really applied as liberally as I would have liked.
I discovered this when I disassembled mine to desolder the trim pot. More on this later.
On the exterior of the casing you know I added more heatsinking. Since these areas are recessed, it required a bunch of cutting grinding and filing and drilling, to get them to fit tightly and not obscure the screw heads( blue tape) which secure the transistors tightly to the casing.
I was using what I had on hand.
Had I not had these heatsinks on hand, I would have bought these, or products similar:
https://www.amazon.com/BNTECHGO®-Al...7_1?ie=UTF8&psc=1&refRID=0T6EZHTQ809DV5TX4BJ3
https://www.amazon.com/Enokay-Cooli...7_6?ie=UTF8&psc=1&refRID=D30RW0VPFSPEJXR9CDAX
And as much of the casing as possible would be stickered like a porcupine with heatsinks but centered at least around the transistors. Not the Steel lid though.
I think those come with self stick pads for mounting. More effective without the pad. How much? I don't know.
https://www.amazon.com/Arctic-Silve...476063258&sr=1-2&keywords=arctic+silver+epoxy
Honestly I added the exterior heatsinking at a much later date and after much use, and there was no improvement in performance. It would hold 40 amps to absorpton voltage before and after just as well. I do not have temperature data on the before, only after, but the transistors have to be running significantly cooler for them.
Another fan blowing over the casing would be even more beneficial with the added heatsinking. I have a USB source mounted right above mine whan cabinet door is open, and plug in a USB fan and aim it at the MW, but this does not get the flow on the right side of the case on mine.
Kind of looks like you installed a 120v switch on the right side? I just plug mine into my power strip and plug/unplug it or use the master switch on power strip.
Regarding the voltage trim pot.
Do you feel the need to change voltage often in your usage? The provided 1K ohm mini trimpot is only rated for 50 cycles. The unit is designed to be adjusted once and installed to power various electronics, not as a battery charger with different voltage needs adjusted manually often.
My Soldering skills were not what they are now. After Disassembly of unit for access to bottom of circuit board, I tried to desolder the trimpot using a solder sucker, and cursed a lot.
If I had to try and remove trimpot in one piece, I would use gravity and an alligator clamp to exert even pulling pressure on Trimpot while I heated the legs with two solder guns/irons at same time.
But since installing the new Potentiometer, I've learned more, and likely would try and destroy the trim pot and access the 3 legs which I would want kept as long as possible. Only 2 of the legs need wires soldered to them. The third is electrically connected on circuit board and does not require separate wire.
Access to the trimpot in its location on the Meanwell is the issue, and the proper tool to get in there and keep the legs as long as possible.
https://www.amazon.com/s/ref=nb_sb_...sh+cut+pliers&sprefix=flush+cut,computers,205
I would not change the resistance range, the original potentiometer is 1K ohms, replace with the same. Full resistance is the lowest voltage, 0 resistance relates to the highest Meanwell voltage.
http://www.ebay.com/itm/New-1K-Ohm-...Turns-Counting-Dial-Rotary-Knob-/161785993268
An Ammeter would be more useful than a voltmeter, but both is better.
This is why i use the GTpower wattmeter. But the provided 12 awg leads are not acceptable long term at 40 amps.
So I modified my wattmeter with 8awg, but this too is not all that simple, and I have destroyed one with a solder bridge when soldering 8awg to the tiny shunt.
https://www.amazon.com/Power-Analyz...=1476064955&sr=8-3&keywords=G.T.POWER+RC+130A
There is one the WATTS UP clone (Windypower version) which comes with 8awg tinned copper leads, I bought it. it has issues, I do not recommend it. It freezes and voltage and amperage jump around wildly when not frozen, and the AH and KWH figures are completely inaccurate.
Do note that when I am not using the MEanwell, I unplug my 45 amp Anderson powerpoles from the battery, otherwise my fans always run and the wattmeter is always illuminated. The MW has overvoltage protections built in, which one can hear click when the battery is disconnected. I try to always disconnect the DC, then the AC, and the fans and wattmeter stay lit/powered up for a half second afterwards.
I do not know if having the MW hooked to DC unhooked to AC causes a parasitic draw on the batteries, other than on mine the fans and wattmeter certainly do. I also plug mine into AC, then adjust voltage unloaded, then plug in DC powerpoles.
The ammeter is good in your usage as you can determine that X amount of amps means batteries are ~90% charged, and all you are willing to expend generator gas upon.
The wattmeter is nice as it counts to 64 Amp hours( flips to zero and starts over) and you can see how much capacity(AH) you returned to battery, even though some of them were turned to heat.
You could use one of these too:
https://www.amazon.com/bayite-Digit...1476065501&sr=8-1&keywords=bayite+hall+effect
Mine is accurate enough on Amperage, but reads 0.2v low on voltage.
It will toggle between voltage and amperage or both via a small button on backside of the display.
The hall effect sensor means one just runs (+) or (-) wire(s) through it instead of using a shunt.
Since you will primarily be using this as a 40 amp bulk charger, where it will generate the most heat, the additional heat removal improvements should increase the units longevity and reliability.
Reading the Ammeter and voltmeter or wattmeter tell you when there is no more point to run the generator to recharge the batteries to a true 100%, which takes forever from 90%.
If you do not ever use this to float your batteries and act as a DC power supply, then the voltage pot modification will be of limited benefit. Just set it to 14.8 or whatever amount higher, to account for voltage drop on the wiring at 40 amps, and use it as a 40 amp charger only.
Since you have in the past said you are not concerned with charging from 90 to 100% to maximize battery life, then adjusting the voltage to account for battery temperature is not likely to happen either, so perhaps the voltage potentiometer is not really worth the effort of installing in your proposed usage.
Personally, I can and do plug in and seek 100% charged for maximum battery longevity, and I adjust my voltage often and the potentiometer modification is mandatory, and satisfying, and on occasion has elicited a maniacal laughter.
The little black plug with the four outlets are for voltage sense lines to account for voltage drop on the DC outputs, and I believe a remote for turning it on or off. I do not employ them.
