A long time ago, 2014, I bought an APC ES 750 UPS. It served faithfully until the battery croaked. To my mind though, it ran out of juice too quickly. So rather than spend $$$ for an OEM battery, I hied myself to the Mart of Wals and bought a lawn tractor battery. I was able to wire it in externally, and I ran it for many years. I would keep Himawari running for a good 15 minutes with the monitor and cable modem (and network switch) fired up. Lately, I've been awakened, or come home, or just been sitting at the computer when it would suddenly shut off and start the continuous alarm. I assumed that since it wasn't running off the battery, that perhaps the battery was bad somehow, even though it seemed to be fully charged (like, perhaps it had cycled enough times that it had lost capacity). So I hied myself again to the Mart of Wals for another battery (They also stock the APC 450 unit, not gonna touch that).

This did not solve the issue. Although it did let me get rid of a dead automotive battery I'd been using as a doorstop for the screen door and recoup the $12 core charge. Now I have two perfectly serviceable 12 volt lawn tractor batteries.

So last Wednesday we had a massive wind storm that knocked out the power overnight. Around 2 AM the UPS screamed, so I staggered into the living room and found the power button and punched it, to silence the device.

And then my ideator ideated, and the idea involved inrush currents, so I decided to see what would happen if I slowly turned things back on. Hitting the power button on the old UPS set it going on Battery. Then I started Purah. When it seemed to be booting, I turned on the monitor. So far so good. Until it got to the point of changing the signal on the video card, which turned on the sound bar because of how it was connected to the monitor, which was a load I didn't anticipate. Instead of an alert, everything snapped off and there was a loud *POP* followed by a hiss, and a tiny thread of Magic Smoke snaked it way through a vent hole. I quickly unplugged things from the unit, unplugged it from the wall and detached the battery - the wires were rather warm.

Yeah, so what happened that a battery and UPS configuration that could support my old PC, Himawari, and the old flatscreen, was not up to Purah's power requirements. The oversized battery could supply it, but the UPS couldn't handle the power. And that's the actual alarm mode it was showing all those times it shut down. It was overloaded.

When I got back from work that day, I did a post mortem on the unit. One very obviously popped electrolytic capacitor had given its life. But there was also marked corrosion clumped up around the base of a couple of FETs and their aluminum heat sink block right next to it. I'm not sure what, if anything, that contributed to the issue. I have pictures but that's a bit too much of a pain to put up here.

Since we have a dearth of computer stores like Fry's (RIP) in the nation's northern tech capitol, I consulted the River website, and looked at the largest capacity APC units that weren't intended for Data Centers with infinite budgets. There are three 1500VA units in the line, but other than "True Sine output" there's not a lot of difference between them, and considering everything these days has its own switching power supply that runs on anything you feed it, I went with the least expensive unit - which was still almost $200 for something I rarely depend THAT much on. But I also had $150 in gift card points and some more on my Chase card, so in the end I was out less than $50, and it got here in two days with Free shipping.

It's sitting beside the desk right now, happily saying it will run for 600 minutes with zero load on it. Eventually I'll have to shut down and reconnect things to it. The one downside compared to the other units is a lack of wall-wart spaced outlets, but I have a number of tiny 4-outlet power strips that can displace the wall warts for the router and cable modem. I will definitely move the sound bar off the battery back up circuit.

For the curious, here's an affiliate link to the unit I got. 

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