Will be returning. This is a peak 5000 Amp unit, per the manufacturer's and Amazon's websites, not an 8000 Amp unit as advertised here. (Model %23 TM18). The air compressor functionality is crap. It will run for maybe 3 minutes before it throws a code (H8) that isn't even referenced in the user manual, and quits running. I assume it's an overheat issue. It ran again about 10 minutes later for about 30 seconds before throwing H8 and ceasing again. Absolutely worthless.
The battery jump starter function is not simple. The 3 lights on the face of the unit (red, yellow, green) indicate the approximate charge of the unit. Gives you a total guess of how many jumps you might have left. The power button does not turn off the unit, so if you don't make it back to the ignition in about a minute after powering on, you have to cycle through the light options to get the Ready light to come back on. It does not give you the voltage charge of your battery like many other units do.
It made a click noise every 10 seconds while it was attached to the battery and turned on that concerned me just a little, it also sounded like it was sparking a little while I did not have eyes on it. I followed all protocol properly. Red to red, black to black, in that order. Then powered on the unit and ensured was in jumpstart mode This was standard jumpstart not the bypass function. It did start my vehicle with only 1 try which is why it's getting a 3 star review and not a 0. I have a V8 SUV 4x4 truck, size 27 battery. So it had enough power to jump it, but I would not trust it for anything bigger given the false advertising of its Peak Amps here on Walmart.
The user manual is confusing. There is absolutely no product support or troubleshooting anywhere online, no YouTube, nothing. A phone number (I think) to somewhere in China.