Let's ideate on making a Level1 UPS that doesn't suck

Hardware
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Gear UberNerds need that is almost universally super crappy:

  1. KVM Switch (Level1 KVM WOOOO!)
  2. uninterruptible power supply

So maybe making a UPS that isn’t utter garbage is next on the level1 todo list. Anyone want to contribute?

My opinion is that the best UPS tech is, by far, a flywheel: https://www.qpsolutions.net/2017/06/intro-to-the-flywheel-ups-powered-by-motion/

Unfortunately, I’d like to build a UPS for an ubernerd that is also not wildly expensive. We were able to build a durn good KVM, one of the very best (though imperfect), that was also one of the least expensive KVM options out there. Can we do it again with UPSs?

It seems to me it comes down to the battery. I haven’t done any R&D on the battery yet, not really, but something easy and with a life of at least 5, hopefully 10, years would be ideal.

I think that rules out the standard battery type in most UPSs – sealed lead acid. These are hit and miss. the good ones can have a lifetime of 5 years but the cheap ones barely last a year.

Lithium Ion is out because it can’t wait to catch on fire and was not designed to store a charge for a long time.

A UPS built of super capacitors is something I have seen at computex. I will gather more info when I go there again this year (hopefully).

General parameters for the battery would be something that could cost less than $200 while providing something on the order of 250 watt hours of energy storage.

One other downside of super capacitors is that their voltage drops as they discharge unlike other battery technologies and it might be problematic dealing with that.

( It could also be my friend Eric sucked me into thinking about this… http://esr.ibiblio.org/?p=7839 and so… by proxy… I lean on you, the smart and good people of the forum. that reminds me. pls no trolling k thx bai)

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Is it possible/potentially beneficial to tier different battery types, or would that just add ridiculous cost?

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Possibly, if we can link to suppliers since this will likely be DIY or quasi-DIY territory.

Lead acid battery replacement is imho too costly to make doing that with “normal” UPSs worthwhile which is why I was hoping for alternative “10 year” technology… like a supercapacitor.

This UPS for example is almost not garbage https://www.amazon.com/APC-Back-UPS-Battery-Protector-BR1500G/dp/B003Y24DEU but the failure rate is pretty high and 2-3 years is about all you get out of it even though the battery is replacable.

the pattern for me personally has been new one lasts 2-3 years. Replace only battery. Replaced battery lasts 1 year or less and the UPS itself gets visibly more flaky. Planned obsolescence? idk

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The old Edison batteries…Should have the life span you are looking for…But I don’t know how big it would need to be for 25o watts…

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Do we care about size/weight?

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Looks like about half the energy density of lead acid. It could work. Now I just need a chinese supplier… a US supplier for modern versions is about $1k for 12v @ 100ah so… kinda pricey haha.

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Yeah just saw that …

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LeadAcid or LeadGel cells have that one problem of forming Hydrogen under fault conditions, apart from that, they are pretty much fool proof and forgive pretty much anything.

For lithium ion batteries, 250Wh equates to arround 1kg (with added explosiveness under fault conditions)
NiMh is at 3.2kg (much safer than anything lithium)

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NiMh and Lithium Ion are unlikely to maintain even 50% capacity over 10 years if kept in a continually fully charged scenario though.

Modern 12v sealed lead acid batteries are lasting < 3 years for me at this point before they fault internally. Some of these cells I’m pulling from the APC will literally rattle. Those are sealed gel cells right?

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Battery technology leaves a lot to be desired…
The really good ones for offshore UPSs have an expected service life of 20k hours. And that is kind of shitty for very expensive equipment.

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Could an inexpensive, low capacity (maybe redundant) battery layer be used to even out the voltage drops from the super capacitor?

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You need some circuitry to produce 50Hz AC sine wave anyway. So the voltage drop would be cought in the boost converter before the inverter.
The real issue is the droppoff at the end of the battery capacity.

Edit: For a 250Wh battery, you will get about 220Wh useable capacity.

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Yeah, I guess I meant a small supplemental battery to use as a stopgap to extend the capacity… I’m not sure if that’s feasible, just a thought.

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An aside from the which battery to use discussion. One thing I’ve wanted in a consumer UPS is the ability to expand the watt hours. I’ve worked with commercial UPS’s that have battery unit(s) attach to a controlling unit. Some of them are even small enough to be in a rack mount format. I’d like to see something like that in a nerdy, consumer (nerdsumer?) UPS. Basically plug in an additional battery unit, doesn’t even have to be a whole lot larger than the original unit, and get additional watt hours.

Most APC’s I’ve seen just use the typical sealed lead acid batteries with F2 terminals.

Also, someone I follow on Youtube, Mark Furneaux has done some work with super caps.

And has a few choice things to say about the quality, and battery life, of APC units.

Also he has a video in which he plays with some 19 year old lithium ion cells.

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Lifepo4 battery?

Also what about a supercapacitor.

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You would need to controll each battery seperatly to prevent extreme currents flowing between the cells. So the number of expensions is predetermined (3 internal, 3 external?)

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ackchyually
ackchyually.png700x700 20.7 KB

many types of batteries have voltage reduce with the charge

but, should still be doable, would just have to look for inverter or whatever that could accept a variable input, or at worst a regulator before that which does(less desirable since extra efficiency loss)

could just do some calculations when designing the capacitor bank to size it so that you could still get the desired power if you just had it shut down(like overdischarge protection) but to prevent it from dropping out

but super caps also present some other challenges, in sourcing them, mean can get them from coin cell shape, or skittle sized, to like a radial cap the size of a tall boy beer can maxwelll 3000f. in that you will have to design the battery(if cant find a suitable array design online), instead of being able to build it around the battery

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What would be wrong with something like this? http://www.batteriesasap.com/dc260-12.html
I know it’s double what the price Wendel is trying to target but It’d be worth it for 10yrs life.

edit: OH SHIT it weighs 172 pounds… LMAO

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I think it would be best identifying exactly what sucks about current UPS offerings, and addressing those criteria.

Honestly, sealed lead-acid batteries are probably going to be the most pragmatic choice if cost is the main concern here; what about thinking outside the box (literally, as in the UPS chassis) and focusing on an integrated control system which focuses on making it easier to A) identify and B) switch out dying units and C) replacing them without involving the corporate treadmill?

Super caps are a way to solve the longevity problem, but you’ll pay for it in cost per unit and usable capacity as they can discharge a huge amount of current but can’t store it for a long time.

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Got basic charge controll, boost converter with some stabelizer and fail safes/circuitbreaker layed out. Am way beyond the 150 parts count and probably does not comply with FCC or CE standards.
Consider me mad man!

Capacitors are meant to smoth out voltage differences, not store energy.