Review on AIMS Power CON120AC1224DC AC Converter & Battery 12V or 24V Smart Charger 75 amps UL 458 & CSA Listed by Chadwick Webster

defect straight out of the box. I bought this device in early February 2020 for LiFePo4 4s 12vDC @ 100aH battery pack for offline system. It was sold in the Inverter Store. They have an excellent reputation in the autonomous network industry. The unit arrived in Detroit from Navada in a few days. I have it open to date (February 22, 2020). The production date on the box states it was made on April 19, 2019. The batteries were ordered the same day from a well-known Chinese website and distributor. However, the corona virus and the lunar new year have slowed down the delivery. The batteries and BMS arrived today and are new in the box. I connected the batteries in series with the power rails and installed the BMS. I then discharged the batteries to 20% using a 1000W pure sine wave inverter. I removed the wires (4AWG weld wire) from the inverter and installed it on the charger. I heard something clicking like a relay in the charger (maybe something else) and this indicated an error (red light) as the unit was on when it arrived. I did not see any flash or arcing from the cables when installing them on this unit. I flipped the device's power switch to the off position and plugged it into my home outlet. I turned on the device, but it wouldn't turn on. I've tried several times by turning off the device and unplugging the battery cables multiple times to no avail. The red error light returned every time I tried to turn on this device. I ran this cycle in my heated garage at 60F after the batteries were at room temperature. (Never charge LiFePo4 batteries below 32°F). I could not turn on this device. I checked my home signal and it was 120.4 VAC, 60.1 Hz and a very clean signal (sine wave). Also, I was very careful NOT to reverse the polarity of the device. I bought a red and black 4 AWG welding wire to eliminate the possibility of polarity reversal between the charger and the inverter. I removed that block and reinstalled the 1000w inverter and the inverter worked fine. So the problem wasn't the BMS/batteries. It was definitely the charger. This is very frustrating because the design features are exactly what I'm looking for. Planned to charge at 0.5C (50A). This unit is said to deliver 75A at 12V, so there is a safety margin and the unit will never reach 100% (75A). BMS is rated at 60A. So the design specs are perfect for my needs; however, processing is a problem. This device is made in China and comes with "QC OK" stickers. I've been to several dozen Chinese manufacturing plants (auto components). World-class production methods were not accepted by most of the manufacturers I visited. So anything made in China is crap, especially anything electric or high-tech. I have initiated a return so I will let you know if there are any issues with the return from the inverter shop. They have a very good reputation and I don't expect any problems with returns. Hopefully this device can be fixed with something as simple as a blown fuse. This device is sealed and contains no good parts. I will update this when my return is processed.