An uninterruptible power supply for A/V cabinets (lithium-ion!)
Even an antique house like ours (2003) here in Florida comes with an A/V cabinet (example from Leviton), the natural home of routers, switches, etc. because this is where all of the Cat 5 cables (Cat 5e in our case; Cat 6, obviously, for newer houses (6A is stiffer and maybe builders wouldn’t want to use it?)) to wall plates end. The Florida Power & Light grid has amazing uptime, but our epic afternoon thunderstorms do cause 1-2-second power hiccups. That’s enough time to force a 5-minute reboot of our cable modem (still in an Xfinity coax ghetto here). Having failed to find what I expected to be a wallet-sized lithium-ion-based UPS, I set the cabinet up initially with a CyberPower lead-acid-based uninterruptible power supply (UPS) of absurd weight and capacity given the use case:
The CyberPower began to shut down randomly, despite the low load. Replacing the battery didn’t help. CyberPower did not want to offer a warranty replacement. Another summer arrived and we had a couple of power glitches. I found that Liebert, the storied manufacturer of machine room AC, introduced the Vertiv PUL-350LVT back in May 2026. This costs about $142 at Amazon and can handle 210W, which seemed potentially insufficient given that the Netgear GS116PP PoE switch by itself can supply 183W of output. Due to the lack of a lead-acid battery, the weight is just over 3 lbs. I used a Tapo P110M smart plug to see what the total draw from the cabinet was (cable modem, Omada router, Netgear PoE swtich) and it turned out to be just 72W steady-state (I rebooted most of the Omada access points at the same time and power consumption did not spike). The UPS will keep our home on the Internet for over 10 minutes, therefore, in the event of a serious FPL problem.
Tangent Alert! Maybe we should buy Vertiv stock? No matter who wins the AI and data center wars, Vertiv/Liebert will have to be paid! They’re like Levi’s for gold miners, right down to the 2SLGBTQQIA+ passion:
The company also seems to admit that it doesn’t pay employees fairly:
Why is there “work we need to do to improve”? If Vertiv/Liebert pays employees what they’re worth, what would be an improvement? (paying some employees more than they’re worth?) If Vertiv/Liebert does not pay employees what they’re worth, what stops them from adjusting pay right now?
But I digress…
Returning to the question of lithium-ion to sit behind the small boxes that are critical to home happiness…. so far it works! (I bought it at Amazon, set it up in a few minutes, and simulated a brief outage by unplugging it a day after the install.) The only unknown unknown unknown is what happens if there is a 20-minute outage, the batteries die completely, and then power is restored. Will this thing turn itself back on? When initially plugged into the mains, it did not come on without me pressing and holding the button.
What would be nice to have? How about a small light lithium-ion UPS for a desktop PC with a standard 750-1000W power supply? Instead of the lead-acid monsters designed for max runtime, this would have enough battery for only a 1-minute outage and then a 2-minute orderly shutdown if the outage persisted. Let’s assume kind of a worst-case draw of 1000 watts for all three minutes, which is essentially impossible (GPU-intensive processes would be shut down shortly after the first minute). This could be accomplished with a 12.8 V 10 Ah LiFePO₄ battery, I think, that weighs only 2.7 lbs. and costs $60. It’s about 6x3x4″ in size, though, so my dream of having the UPS built into the PC power supply might not be achievable. (On the third hand, maybe the dream IS achievable. The power supply can have a small LiFePO₄ battery. If mains power dies, the power supply can pull power from the GPU after 5 seconds in order to give the motherboard/CPU/any hard drives another 55 seconds and, then, if the grid is still dark, sufficient time for an orderly shutdown. Maybe the unexpected disappearance of the GPU would cause an LLM or video game to crash, but that’s unlikely to leave any files corrupted.)
Full post, including comments






















