Now THIS is a UPS

[Red Squirrel]

(my camera takes terrible pictures in the basement, I don't know why. They're always out of focus)

That's a Tripp-Lite APS750 750w inverter-charger I got off ebay. Surprisingly hard to find an inverter-charger that does pure sine wave and can switch fast enough for computer equipment to not notice. You'd think these would be more available but they arn't. I would have rather go with 24v or 48v system though but this does the job. This one is not pure sine but it's a compromise between square and pure sine so it gets the job done. I have two 100AH marine batteries hooked up to it.

I ran a test and it ran a 300w load for about 5 hours. My initial calculation was 8h but that was without taking inefficiency and voltage drop into account. As the voltage drops, the current drawn is higher, so this makes the battery deplete faster. I was not checking often enough but my last reading was 11.1 and I noticed the systems were off maybe 15 minutes later so my guess is the shut off is at 11 volts. This is some logging I took, thought I'd share:

time voltage
1:00 12.3
1:22 12.2
2:10 12.1
2:21 12.1
3:17 11.9
3:40 11.8
4:26 11.6
4:39 11.7
5:04 11.4
5:42 11.1


Now I just need to find a way to read the voltage through my linux box so I can monitor it remotely and possibly even have an automated process that shuts down everything when it reaches 11.2 or so.

Eventually I want to get a cable crimper and ends and a roll of cable so I can make my own cables, and also a solid shelf for the unit as well as the batteries to get them off the floor in case of water issues, but for now it will do. The display of the unit is actually where the cables connect and because I could not find cables that were longer I had no choice but to place it that way.

My far future goal is a fully online high capacity (3kw or so) 48v system though but this will do for now. It's not so much that my stuff is critical, but that it is hard on the equipment to cold boot it because a lot of it is old, so I rather ride through outages and keep the disks spinning then to have them turn off. Had a 2 hour power outage the other day but this was not arrived yet. I will keep it running on my test load for a few more days then put my server stuff on it. Summer is notorious for 1-4h outages due to the construction in my area as well as the wind/storms. We had a 4h one last year that nearly killed my server. Ended up putting over 1k into it to get it going again. A typical UPS will only last a few minutes.

 

[TheSiege]

Get a transducer to an input, like on a PLC

 

[Charles Kozierok]

Pretty nice. Hope those are deep cycle batteries or you're going to be an unhappy camper very soon. Even so, I wouldn't run them down to 11.1 -- that's really pushing it unless they are very cold.

Be careful about ventilation of lead-acid batteries in the basement.

 

[xSkyDrAx]

Those Tripplites are freaking heavy.

 

[reallyscrued]

Very cool. I love things like this.

 

[Charles Kozierok]

To add: you should look into proper safety protocols for this type of system in general. For example, your terminals should be taped (guess what happens if that floor fan falls in exactly the wrong way?)

 

[Red Squirrel]

Get a transducer to an input, like on a PLC

For the voltage reading? Yeah I'm thinking maybe Arduino or something. I may build a general purpose data acquisition device and use that. I don't know much about electronics but data acquisition is fairly easy to do with a premade analog input USB device.

And yeah those are deep cycle marine batteries. Idealy I wanted pure deep cycle but these are starting/deep cycle so they do have a CCA rating. I'm guessing pure deep cycle would be better.

They do put out some hydrogen I imagine but I doubt it's enough to be a concern. The system is not fully online so they only charge when needed.

I may get 2 more to double the uptime though. They're only 120 bucks or so, compared to the 200 bucks that APC would want for a 7ah battery.

 

[Red Squirrel]

To add: you should look into proper safety protocols for this type of system in general. For example, your terminals should be taped (guess what happens if that floor fan falls in exactly the wrong way?)

Yes I've been thinking about this. Not sure what I want to do yet but I do want to come up with some kind of cover. I may actually put them in a Tupperware container and cut some holes for ventilation. They do make battery boxes but a Tupperware container is much easier/cheaper than ordering something online.

 

[Blain]

Get some AGM batteries and shut down the hydrogen gas factory you have going in your basement.

 

[Charles Kozierok]

Get some AGM batteries and shut down the hydrogen gas factory you have going in your basement.

AGM batteries are expensive. Regular cells are fine as long as they are ventilated -- and that becomes more of an issue if they are in a battery box (though the box has other advantages).

And to reiterate, at 11.1V you are getting dangerously close to "I've fallen and I can't get up" levels of discharge on lead-acid -- even for deep cycle. That's something like over 90% discharge -- full is 12.7V.

 

[Red Squirrel]

good to know about the votage, what is a safe voltage to shut off, 11.5? Keep in mind that when the equipment did shut off, the voltage reading was over 11.1, I forget what it was but think it was like 11.7. The inverter-charger's instructions say it shuts down to prevent excessive discharge so I'm guessing the voltage it shuts down at must be safe, or should I still shut down before?

As for hydrogen, if any hydrogen is produced that means I lost some electrolyte right? So should I be keeping track somehow of how much is lost and add distilled water every now and then? I figure since this is not a true online system I'm probably fine though.

 

[Charles Kozierok]

good to know about the votage, what is a safe voltage to shut off, 11.5? Keep in mind that when the equipment did shut off, the voltage reading was over 11.1, I forget what it was but think it was like 11.7. The inverter-charger's instructions say it shuts down to prevent excessive discharge so I'm guessing the voltage it shuts down at must be safe, or should I still shut down before?

Good inverters can usually have their shutoff voltage adjusted. I am not sure exactly what the definitive "safe" voltage is, but when we were living off grid I tried to never let my batteries go below 11.7. (That's a reading not under load, mind you -- loads will drop the voltage further.)

I don't think you did any damage to your batteries, but in general, you don't want to cycle them "super deep" unless you have to.

You may find this FAQ useful. The site has been around a long time.

As for hydrogen, if any hydrogen is produced that means I lost some electrolyte right? So should I be keeping track somehow of how much is lost and add distilled water every now and then? I figure since this is not a true online system I'm probably fine though.

Hydrogen is produced during the charging process. You do have to check the electrolyte levels regularly.. follow whatever procedure the manufacturer recommends. If the charger is smart (and it sounds like it is) then it should scale back when the batteries are near full to avoid overcharging, which is what causes most of the problems with fluid loss.

 

[imagoon]

I highly recommend a battery box. Having seen the inside of a 30kva UPS [stand alone battery box] after a cell blew, I wouldn't have wanted to be around that battery in the open. The box also kept the flaming wreckage inside rather than flinging it on to potentially flammable objects.

 

[Red Squirrel]

I took the suggestion of enclosing it, I kinda wanted to anyway but the thought of having something fall between the two terminals kinda made me make a priority of it.


(cover removed)

Also got two pieces of Drycore to raise it up a bit. I do have a few leak issues in the basement and while that area is ok, better safe than sorry. Getting the leak issues fixed this summer though. I also need to tidy up the cables and stuff behind there, I'm still in test phase so I got a split wire adapter hooked up so I can check current draw to calculate wattage.

I went with the Tupperware container as while Canadian Tire DID have battery boxes, they only had terminal holes on one side, and figured if I'm going to buy something only to modify it, may as well buy a single big container that can hold both batteries. The main idea is to hide the terminals and this gets the job done. I actually like this better as it's easier to open and semi transparent so I can get a quick visual whenever I pass by there.

I almost bought two more but decided against it, I need to stop spending money, and 4-5 hours is plenty of time for 99% of outages. We don't get that many outages and when we do they usually last 1-2 hours tops.

Overall not the cleanest looking setup and it would be better off on a shelf/cabinet of sorts, but it will do for now. At some point I want to find a place to buy cable ends and a crimper and crimp my own cables that way I can get longer ones. Idealy I would have liked to put the inverter charger itself in a position where I can actually look at the display but I was constrained by the short cables.

 

[Gillbot]

Looks similar to mine, i'll have to get pics. Mine is an APC unit that was rescued from a closing store. I only have two smaller batteries on it so I'm not sure what the run time is, I mainly use it for brownout protection.

 

[mfenn]

So the real question is where'd all those IBM disk enclosures come from? :awe:

 

[Charles Kozierok]

Get some colored electrical tape, red and black, and tape the terminals once the setup is (mostly) complete.

 

[Red Squirrel]

So the real question is where'd all those IBM disk enclosures come from? :awe:

I got lucky and managed to get it for free, it was being thrown away. Got 4 of them. the 2 top ones are 400GB drives and 2 bottom ones are 250GB drives. It's fiber channel and when hooked up all the drives show up individually so I can use linux mdraid or other solution to raid them. Only thing that sucks is I can't put my own drives in it, they're sata but they have some kind of special firmware or something. I use it for some occasional backups or if I need a bunch of temp disk space for something, but I don't have anything production on it. As disks fail I can't replace them. None have failed yet though. It's cool to watch it boot up too, so many blinky lights.

There's a big + and - symbol on the batteries, so it's easy to tell which is which.

 

[mfenn]

I got lucky and managed to get it for free, it was being thrown away. Got 4 of them. the 2 top ones are 400GB drives and 2 bottom ones are 250GB drives. It's fiber channel and when hooked up all the drives show up individually so I can use linux mdraid or other solution to raid them. Only thing that sucks is I can't put my own drives in it, they're sata but they have some kind of special firmware or something. I use it for some occasional backups or if I need a bunch of temp disk space for something, but I don't have anything production on it. As disks fail I can't replace them. None have failed yet though. It's cool to watch it boot up too, so many blinky lights.

There's a big + and - symbol on the batteries, so it's easy to tell which is which.

Nice, not too many people have an FC SAN in their house. I'm guessing that you scored the HBA for pretty cheap as well?

 

[Red Squirrel]

Yep got a bunch of HBAs too. Not that I needed all of them but since they were not being used I grabbed them. I have a FC switch too, but I could never figure out how to use it so I just have the enclosures going straight to the HBA which is in the small supermicro server. Fun stuff to play with that's for sure, and it's always fun to show people that come over.

This is the whole setup:

 

[Puppies04]

Be careful about ventilation of lead-acid batteries in the basement.

This +1 be careful

 

[mfenn]

Yep got a bunch of HBAs too. Not that I needed all of them but since they were not being used I grabbed them. I have a FC switch too, but I could never figure out how to use it so I just have the enclosures going straight to the HBA which is in the small supermicro server. Fun stuff to play with that's for sure, and it's always fun to show people that come over.

This is the whole setup:

:thumbsup::thumbsup: Baller.

 

[Red Squirrel]

Switched over my main stuff to the new UPS today. I also noticed the cmos battery in my server is dead lolz. that's what NTP is for. This server will probably not go down anymore till I revamp the server room anyway. The SAN is not on UPS, that thing draws like 1kw. I only turn it on as needed, which is probably not that good for the drives.

Right now I have no visibility on the status (power outage or battery voltage) but I have an arduino board coming in the mail which I'll use to monitor power state as well as the battery voltage. Also ordered a hydrogen sensor off ebay which I'll connect to that board. In fact will all the inputs on that board may as well hook up various sensors and stuff to it. Perhaps even a methane detector in the furnace room. I can go all out.

Once I figure out how to setup the Pandora agents I could have full blown environmental monitoring going on. I work in a NOC, guess my work is growing on me. I just want to monitor everything!

 

[Red Squirrel]

Found this thread while searching for another, I thought I'd provide an update since a lot has changed, added a battery rack and some fuses and switches. Overall safer than what I had and capacity to add more batteries.










Custom app to monitor voltage (among pretty much anything else around the house or within my server environment)


4 batteries total now. Unfortunately can't add 4 per shelf given limitation of container sizes I can find, but in the future I might just get some custom made trays or something. It's mostly a precaution in case a battery decides to leak, at least it's contained.

Oh, and also got a better camera.