All posts for the month March, 2021

Until the past two weeks I’d only owned two Uninterruptible Power Supplies, aka UPSes, but that’s changing a little bit for a few reasons.

My first was a Cyberpower unit purchased in the very early 2000s from one of the Office stores, aka Office Depot, OfficeMax, or Staples. It was 750 or 1000VA and serviced me well for a few years but the battery failed earlier than it should have. I liked the idea of a UPS, not only for it’s power backup but that it conditioned the incoming power and gave a much better and more consistent output than one could expect from a wall socket.

Less than a year later I purchased an APC BX1000, likely also from another Office store deal, and it worked great for much longer than I expected. APC is the name in UPSes around the world and I was bummed when the twin 7.5ah cells died after what was possibly 10 years on the job. At the time the replacement cells were more expensive than I was comfortable spending, so it went into a closet and sat.

Recently, however, a local recommended a site that I’ve now used for very affordable and reliable cells, The 3.5ah and 7.5ah cells are usually about $11 each, and they ship from the US out of Nevada in a USPS Flat Rate box for more than the cost of an individual battery. Batterysharks carries a LOT of batteries, but when replacing the twin cells in my BX1000 I just needed a direct replacement.

Being careful to remove the cells, which hadn’t expanded, leaked, or otherwise deformed, I was able to install the new cells with the OE harness that places one battery, inverted, above the other, as this UPS is a tall tower. Other applications vary, but smaller UPSes usually only require one battery and no harness.

The cells I got from Batterysharks did indeed revive the old BX1000, and I still had the weird USB-to-RJ45 communication cable that it came with. I even had an old version of APC’s PowerChute software, which I knew was compatible with this model and it showed green across the board.

Stoked at this revival for under $40, I remember that a local university frequently has older UPSes that have failed batteries on sale to the public. The cells are usually distended and are always removed prior to sale and recycled. I was able to buy two CS 500, one ES 500, and an ES 350 APC unit for a total of $10 after some haggling. Good thing, as when I tested all four of these with the bad cells from the BX1000, only two of them acted properly. A third gave a weak On Battery light, while the other did nothing, not even an arc when plugging it in.

Knowing that I had a working CS 500 and ES 350, at the very least, two more cells were ordered from Batterysharks. They arrived in a week or so and, just as a final test before sending the two previously dead units to the recycler, I popped the 7.5ah cell in to each of them. I guess they were grumpy before, but now both of them powered on and acted completely normal. Great!

Knowing that I preferred the ES form factor, it being a super-sized power strip instead of a bread loaf, I immediately had a use for both of them. One went to a laptop and PC setup in the basement where I have done some streaming and do a lot of music listening and rating for my channels on SomaFM. The other is now wall mounted in a basement bedroom closet where my NAS, AP/router, and other equipment resides on a shelf. The ES has provisioned holes for vertical and horizontal mounting on a wall, so a few measurements later I had it all up and ready with the ES 500. I’ll be adding the communication cable to this soon and let my NAS monitor it’s status and get alerts for power failures and shutdowns.

In all, the experience with all five of these APC UPSes has been positive. The connectors are robust, the fit is very good with the SigmasTek cells from Batterysharks

Update – 03/27/21

I was woken out of sleep last night by the beeping of a UPS. My ES 500 APC unit, powering a NAS and AP, was doing that intermittent beeping these units do to inform you that something’s wrong. No power outage had occurred. I turned it off, then back on, and it started beeping more rapidly, acting like the battery was bad. I popped the cell into both of my CS 500s, which have been unused so far, and they lit up like Christmas trees also. So, then I swapped the ES 500 for the ES 350 to get things back up and working, while leaving the other cell in a CS 500. It had been making the mid range hum sound like it was charging the cell, so I figured I’d let it. Lo and behold, after about 5 minutes it turned on and is acting normal and sounds like it’s still charging. Perhaps the ES failed because it’s charging circuitry has issues. I’d rather the UPS fail, in this case, than the cell.