New rear fan for linear PSU. I bet packaging more expensive than cooler itself 
PE4302 module from aliexpress:
Really? They were too lazy to solder pad?
Washed my new UPSes from flee market
Ordered Orion LiFEPO4s for the second UPS. For LiFEO4 max charging voltage a bit more that for lead-acid batteries and lower voltage smaller for LiFEPO4s than lower voltage for lead batteries. So lifepos will be never charged to 100% and will be never discharged to 0%, even to 10%. So capacity will be around maybe 4Ah, for my 6Ah batteries, but lifespan will be almost infinite.