Sizing a UPS for cable modem and router; market opportunity for a long duration low power UPS?
Things that our neighbors hate more than Donald Trump:
- cell towers
- underground power lines
Power failures are routine and, when they happen, we lose all communications capability (since a mobile phone won’t work inside the house and only barely works out in the yard).
I’m thinking it might be nice to back up our Verizon FiOS service, including the Internet. Then, in theory, we can at least use our landline and our smartphones or laptops that are charged.
A friend in town says that this is a fool’s errand: “when we had power failures, it turned out that the fiber switch on the street would go down.” On the other hand, this FiOS customer had 72 power outages with Internet in a 6-year period (great advertisement for U.S. infrastructure!).
I’m wondering how to size the UPS to run the latest ONT (corresponding to a cable modem) and VZ’s WiFi router. Verizon sells a ghetto backup battery system, just for the ONT (to run the landline for 24 hours), based on 12 D cell disposable batteries. Wikipedia says a D battery has 18 amp-hours of capacity at 1.5V, so the total of 12 would have 324 watt-hours?
If we assume that the WiFi router draws a similar amount, and will have both boxes plugged into a UPS, we therefore need a UPS with 650 watt-hours of battery? Add another 20 percent for the efficiency losses in converting from DC up to 120V AC down to DC, so now we need 800 watt-hours of battery inside the UPS to run for 24 hours?
It seems to be tough to find this information. UPS vendors spec them in volt-amps or watts and then bury the battery details. Also, maybe Verizon is selling its own thing because the appropriate product does not exist in the market? To get a beefy battery one needs to invest in crazy high max VA, which is irrelevant in this application. A $200 UPS rated at 1500 VA is backed by only two feeble $20 8.5 Ah 12V batteries (204 watt-hours; less than Verizon’s 12 D cells). We bought one to try out and it supplies the ONT and router for 2.5 hours, less than half as long as expected. The higher-capacity machines seem to be marketed as “generators” (without the generator!), e.g., this 412 Wh 11 lb. box for $550.
APC makes a box with a replaceable lithium ion battery for only about $71, which they say is intended to power routers, but it stores a pathetic 41 Wh. Lithium-ion is just not a sensible way to buy watt-hours, apparently.
Readers: Is there a market opportunity here? Apparently providing even the power of 12 D cells on a trickle-out basis is crazy expensive right now. How about a device that holds 24(!) D cell batteries and, in the event of a power failure, will supply power from those batteries to a router and ONT or cable modem? A brief interruption in the power supply is acceptable. Amazon sells D cell Energizer alkaline batteries for about $1 each, delivered. Instead of buying a $500 lith-ion battery that will be garbage after 3 years, just buy $24 of D cells every year or two.
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