edit: I'm probably going to go for the 48V UPS, but...here is the link to the 7S / 24V UPS lithium swap. One of the nice things about 24V is that you can find a 24V alternator, and also alter a 12V car alternator to output 24V, then run it with a lawn mower engine...
There are some 48V Un-interruptble Power Supplies (UPS's) that work fine with a 14S lithium pack, meaning that...in a temporary power outage, your 48V / 52V ebike battery pack can be used to power your TV.
UPS's are designed to make sure sensitive electrical components will continue to run during a short temporary power outage, like computers that control vital components. They use 12V / 24V / 48V packs of SLA, and apparently...when the lead-acid batteries die...it is sometimes cheaper to simply buy a new UPS instead of having a service tech come out and swap-in new SLA batteries. Of course, its not hard to swap-in new SLA batteries, but many businesses simply don't want to mess with anything that they already have a business expense budget for, and they want the UPS's to remain under warranty so the tech-support is carried by someone else.
I was delighted to recently find out that most 24V UPS's with two 12V SLA batteries will run quite well on 7S lithium. Perhaps there are some models that will not, so do your homework before spending any money. However, the higher the voltage, the wider the input range needs to be, so...charging a 14S pack to 4.0V per cell will result in 56.0V at full charge, and it appears that almost all 48V UPS's will work at 14S (52V nominal ebike packs).
The good news for us is that UPS's can often be found on ebay or a local used-electronics recycler for a very cheap price. I've known for a long time that 48V UPS's existed, but I already have three large 52V ebike packs (I feared they wouldn't work, and would fry the $300 UPS experiment). I considered building a DIY power-wall from used laptop cells, but I am very happy to see that my existing ebike packs can now be used. Here's a 15 minute video (episode 45 + 47, "AveRage Joe" on youtube...100-P modules shown, X 14S = 1,400 cells):
Here is a 2700W unit for consideration, input is 48V/52V...output is 120V AC. In episode 49, he compares the standard SUA3000RM2U to the "XL" version of 48V UPS, the SUA3000RMXL3U. Possible to occasionally find these with a dead SLA battery pack for $300-ish...
The cell-end holders were glued-together rings cut from 3/4-inch schedule-80 PVC pipe. Episode 37
Sizing the system:
edit: keeping the cell phones charged up and the laptop computers too would be very easy, along with running a couple LED bulbs and 18650-cell flashlight (for a temporary power outage of just a few days). Roughly 100W-200W if you were doing everything at the same time? Here are the next milestones:
1,000W________________microwave oven, common size
150W__________________TV, depending on type and size, could draw more
1,400 Watt-hours a day___Fridge, large 20-cu ft
1,200-3,800W___________Central air-conditioning, only when running, 10K-24K BTU sizes. A small window unit in the bedroom would draw less?
https://www.wholesalesolar.com/solar-in ... ower-table
It looks like this 2700W UPS would run everything except the A/C, but perhaps I could run a small window A/C after everything else is off and we are going to sleep?...(assuming power is out in the summer). Tornado season is the spring and fall, so it's most likely that for my family, running the A/C is something we could likely live without for a few days.
If 2700W at 120V AC is 22A (the UPS output) then the 52V battery input needs to be at least 52A (2700/52=52), when running at full rated capacity...