Well, as shown in my other posts, my Lifepo4 batteries are installed and functioning well. My broken inverters are still broken. Genetry keeps saying 'soon' for their new controllers. Not holding my breath. I'm making other plans.
Anyway, my best running inverter is still my 3rd old-style clamshell model 48v 15kw powerjack. It has a version 3 or maybe 4 control board and I'm keeping my fingers crossed it continues to perform well. So far, so good. I took advantage of wintertime to do some improvements to it.
Last summer I noticed that the transformers were running pretty warm, so propped up the end of the case lid to improve airflow.
This reduced running temp by 10 degrees but was a bit hokey. Temporary. Foam pieces to hold it up and ducttape to direct the air. Did the job tho. So several months later I finally did a more permanent improvement.
I changed both the transformer fans. (It still had the original weak powerjack fans.) Now the fan in front of the last transformer (this is a 3 transformer model) is a medium speed unit. The fan in front of the second transformer is a high speed fan that runs at half speed when started with the other one. Added an additional sensor that kicks it up to full speed when the temp stays up high enough (higher loads).
Got rid of the foam and duct tape and seated the cover correctly. It's been a month and it hasn't kicked in the high speed once. (It'll see use this summer!) The transformer is running cooler all the time now and the mainboard heatsink is also benefitting from lower running temps.
I have to say these older model, multiple transformer inverters are a better design than the newer, single xfmr models. You need less robust airflow to keep them cool. So its quieter (slower fan speeds needed) and more efficient. Simple math. With the same load spread to 3 xfmrs, your heat buildup is also spread to 3 xfmrs. 3 xfmrs have more surface area than one large one. Less airflow needed to pick up the heat and carry it away. Also the clamshell models shape does a better job of keeping the airflow where it does the most good.
That being said, powerjack managed to screw up the airflow by cluttering up the exhaust end with plugs, connectors, switches and stuff. So I simplified mine and got rid of some of the unnecessary junk. Then I cut the endplate.
You can see part of the reason why the high speed fan hasn't yet been needed. I get great airflow out of that endplate now. And the inverter doesn't run appreciably louder than stock. Clearing the airflow path reduces the resistance to flow and makes the fans work less hard, making them actually run quieter (and more efficient) than they did before the butchering. Looks much better now too. The jacked up lid and tape/foam was a Rube Goldberg setup.