Wait, what? Think about this for a second. There are two possibilities, one of which is absurd and one of which violates code:
- When you draw more than 1440W from this UPS, it switches to battery so it isn't drawing more than 1440W from the wall. This means you can only run your device on battery power, an absurd case.
- When you draw more than 1440W from this UPS, it in turn draws more than 1440W from the wall (it's acting as a power strip), and you've just violated code if you're using a 5-15 receptacle.
In the second case, the battery does not in any way limit the duration of draw.
Ah, erm. That's a good point. Hrm...wait. I got those numbers wrong. You'd want the higher amp one (or even higher actually) to run 1000W continuous, because that amps is in
12v current. So 20a * 12v (really 14.4v for charging) which is 288W. So you'd need roughly 70a charger to keep it going continuously. My math was bad/wrong, my bad, sorry.
So yeah, can't really be used as "online", unless you get (or have 3 or 4 chargers in parallel) to get enough current for the 1000W. And for 2000W, you're absolutely right,
cannot be used online at full capacity without a 20a 120v AC circuit to provide enough power for the chargers. Which is a TON of power.
You want to know something fun? These Goldenmate UPSes are not UL listed. Goldenmate is a brand of Shandong Goldencell, who appear in the UL database as both Shandong Goldencell Power Technology Co Ltd and Shandong Goldencell Electronics Technology Co Ltd ("Goldenmate" does not appear in the UL database at all). The only things Shandong Goldencell have in the UL database are bare cells and battery packs (the ones with lugs they market as alternatives to lead acid for RV batteries and the like). The battery packs inside the Goldenmate UPSes are probably among those that are listed, but the UPS itself isn't. At least they aren't doing the typical chinese fly-by-night thing and putting the UL mark on the box and device anyway.
Heh, that's interesting. In my setup, at least the battery itself is UL listed, which is potentially one of the most hazardous.
Yeah, but this isn't a UPS, it's a battery, a charger, and an inverter. You only have either the charger or the inverter hooked up to the battery, and you don't have your load plugged into the inverter most of the time, so transfer in a power outage involves
- Unplug the battery from the charger if it's plugged in.
- Plug the battery into the inverter.
- Unplug your devices or power strip from the wall.
- Plug your devices or power strip into the inverter.
For the type of use I'd guess you probably have in mind (in your trailer, at Burning Man), that's pretty much what you're going to do anyway, but it isn't what most people would want if they're shopping for a UPS.
Well, assuming (as I fixed above in this post) the 1000W output inverter, you can get enough charger(s) power to keep things running without unplugging stuff to this. Yes, it's basically a battery + charger + inverter. Which isn't that just what an online UPS is? Takes wall power, and converts it to DC, and then converts it back to AC so that when AC power cuts off, it's already pulling from DC. It just starts taking from the battery, rather than from the charger. Just, you know, it a much better packaging and more matched to it's own parts and more QA/etc done on it.
But yeah, going to the 2000W (unless you limit yourself to what you can normally draw from 15a outlet), you certainly could end up constructing the online portion. If you wanted a standby UPS, then you'd need to go for a single unit inverter-charger with an automatic transfer switch. Which would charge slower, and then just switchover within hopefully short enough time when AC power disappears.
