It’s 6am. I woke up because my CPAP stopped. It’s going to be a long day.
It’s a bit cold outside, so I’ll have to fire up my little generator if it goes too long. That’s a pain in the ass.
I took my entire property off grid this year.
I get text alerts about power outages and it’s funny to me now. Like “hmm, my neighbors don’t have power. Damn, that sucks.”
I’m a data center guy so I have plans for an automatic transfer switch and all the other bits. But the budget just isn’t there for it.
Yeah, won’t lie in that it wasn’t cheap but the ROI was immediate for me because I hate relying on regional monopolies.
More “info” below
I’m sure this wasn’t an overnight achievement. Can you please walk us through the steps taken?
Foresee republicans fucking up the residential solar tax credit.
Act quickly on the design I had already outlined.
Modify south part of my roof to relocate all vents to the north (while doing a full roof replacement).
Extended shop 20’ to fit the remaining (of 65) industrial panels needed for a 36kW system.
Add 75kWh battery setup with two inverters and a single controller for it all.
Spend lots of money to secure what I wanted and the 30% tax credit before cap’n Kruger and Fiends fucked it all up.
Was a shit load of work but I did enjoy the process and the results.
Bravo! 👏👏👏
Thanks for the outline!
I woke up because my CPAP stopped.
I understand that some people with CPAPs get lithium power station things specifically so that they don’t stop in an outage.
I dunno how much power those things draw, but a UPS designed for a desktop computer would be perfect for a situation like that. They come in many different capacities, just get one that matches the size of the equipment.
UPC designed for a desktop computer
I wasn’t really aware of this until a few years ago, but UPSes aren’t really generally designed to keep computers running through power outages. Even today, most still have lead-acid batteries (which have limited energy density and don’t deal well with being deeply discharged many times).
They were really designed to solve two problems:
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In a power outage, being able to shut a computer down cleanly. That means time to save documents and — back in the 1980s and 1990s — shut down cleanly, to avoid filesystem corruption, when commonly-used filesystems could become corrupt through not shutting down cleanly. They also often came with functionality to automatically shut down the computer cleanly when the UPS’s battery was getting low, if a human had not yet done so.
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If a generator that automatically comes online in an outage is present, keeping the computer running until the generate giving it time to come online.
This means that UPSes tend to have a pretty decent inverter, can put out a lot of power…but generally can’t store a whole lot of power. They also are guaranteed to come online quickly; I believe that it’s typically in under 20 ms, a blip that a computer power supply can handle.
To grab a random UPS:
https://www.amazon.com/APC-SmartConnect-Interactive-Uninterruptible-SMC1500C/dp/B077Y62GSJ
That runs $529. It has a 900W inverter.
It uses this battery, which is lead-acid 11Ah 12Vdc (so 132 Wh).
To grab a random power station of about the same price:
https://www.amazon.com/BLUETTI-Portable-Station-Generator-Off-grid/dp/B095Y6ZTR1
That’s $500, has an 800W inverter, but has 716Wh of battery storage, about 5.4 times what the UPS does. It also has an LiFePo4 battery, which will last a lot longer in terms of cycles and dealing with deep discharge than a lead-acid battery.
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I guess you’d have to wake up to switch it over, but honestly just a power bank with a standard outlet would probably be adequate.
I dunno how much power those things draw,
https://homegrail.com/how-many-watts-does-a-cpap-use/
Most CPAP machines range from 30–60 watts, with some using up to 150 watts. If you are using rechargeable batteries to charge your machine, you need to be aware of the power required to run it so your CPAP machine won’t shut down in the middle of the night.
The CPAP model I use is meant for travel. When I bought it, it originally offered a bundle including - essentially - a power bank. It looks like that bundle is no longer offered, but now there appears to be a whole range of accessories meant to deal with loss or lack of power.
I rigged up a spare car battery in a box with a small inverter just for this purpose. I used it when my kid was in Scouts. But where is it? Next to the generator in the garage.
I bought a power station for this, and for camping with my CPAP. It’s a 288wh ecoflow river. It runs my CPAP for 3-4 nights (no humidifier of course). They are much cheaper and more powerful than official CPAP battery packs. And they keep your phone charged as well!
My partners BPAP has a built-in battery for this specific scenario
How long does that last? I imagine a Bipap machine must take a fair but of power.
I couldn’t tolerate the CPAP mask so I got an Inspire implant.
