OK, be forewarned, you'll need a 1220 button cell and a power cord.
I currently own a 12 amp model and four of the 18 amp models. I order directly from Riden, they use UPS expedited and it takes about two weeks.
Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com
If you look at the aliexpress link above, it has links to the software, manuals, assembly videos, and operations videos.
The 6 amp model doesn't have a problem, but the 12 amp model sold with a 800 watt supply will have the supply die in about 30 minutes when cranked up to 720 watts output (i.e. 60 volts at 12 amps).
The 1000 watt supply they sell for the 18 amp model won't do above 950 watts, at least that is what Riden says. They also have a software setting to enable you to limit the output so it doesn't die. I haven't tried it yet, I bought some 1200 watt supplies before they got the 1000 watt model in.
Very nice phone and PC app. It has a center green terminal, when you use that it goes into battery charge mode and will shut itself off when the battery is full. If you need any help when you get it, just let me know. Not difficult to assemble, everything is included except power cord and the battery (stores date and time, and Wi-Fi settings if you buy the Wi-Fi module).