Building a DIY UPS

[rjk]

I'd like to see a UPS capable of sustaining a serious mining farm during a blackout. It would have like 50 car batteries lol :p. Imagine an electrical fire or some other mishap then! rofl

Single car battery is able to supply 720W for an hour, in theory. In practice more like 600W before voltage drops too low and due to the age of the battery.
5 for full 16A 230V circuit for an hour.

In other words, that single battery is sufficient for a single 4x7970 rig @ ~2Ghash... Or 1 hour for 10Ghash. Most power outages are solved within that time.

Plus the batteries are free

Damn, I did not know there was that much juice in them car batteries. Since you seem to know a bit about this already would truck batteries be better?

Get a 48v forklift battery and rewire the cells for whatever voltage you need (it's just a conglomeration of 6v cells linked with bus bars).

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[PulsedMedia]

I'd like to see a UPS capable of sustaining a serious mining farm during a blackout. It would have like 50 car batteries lol :p. Imagine an electrical fire or some other mishap then! rofl

Single car battery is able to supply 720W for an hour, in theory. In practice more like 600W before voltage drops too low and due to the age of the battery.
5 for full 16A 230V circuit for an hour.

In other words, that single battery is sufficient for a single 4x7970 rig @ ~2Ghash... Or 1 hour for 10Ghash. Most power outages are solved within that time.

Plus the batteries are free

Damn, I did not know there was that much juice in them car batteries. Since you seem to know a bit about this already would truck batteries be better?

Ofc, they are waaay heftier. But really what you want to look for is the $/Ah supplied, and just make sure they are capable to output 50% more than your required amperage, which is a non-issue unless the batteries are old.

It's quite easy maths really: 12V * 60Ah = 720Wh.

rjk: depends on type of batteries. And what type of battery is 6V per cell?

[rjk]

rjk: depends on type of batteries. And what type of battery is 6V per cell?

Sorry, my bad, not 6v. Standard lead-acid, 2.1v per cell. I don't know what I was thinking.

[Joshwaa]

Just my two cents.  I have done this before for a BBS I used to run(bout 20 years ago).

You get a 1200 Pure sign(169USD) wave inverter put a good power strip to it and plug in the computer. Connect the Power inverter to 4 12 Sealed lead Acid batteries(bout 180USD). At least 20Ah batteries. Then hook a good "automatic on" computer controlled charger and plug that to the wall(must be rated for sealed or AGX batteries).  Do not use regular car batteries as they will vent fumes.  I know it works and its pretty easy. Just keep in mind you will be 10% down on efficency on the power inverter(you gain some by charger not running all the time but it is negligible). So it will cost you more that plugging into the wall. You can adjust the inverter size and battery array to higher loads also.

[legolouman]

Just my two cents.  I have done this before for a BBS I used to run(bout 20 years ago).

You get a 1200 Pure sign(169USD) wave inverter put a good power strip to it and plug in the computer. Connect the Power inverter to 4 12 Sealed lead Acid batteries(bout 180USD). At least 20Ah batteries. Then hook a good "automatic on" computer controlled charger and plug that to the wall(must be rated for sealed or AGX batteries).  Do not use regular car batteries as they will vent fumes.  I know it works and its pretty easy. Just keep in mind you will be 10% down on efficency on the power inverter(you gain some by charger not running all the time but it is negligible). So it will cost you more that plugging into the wall. You can adjust the inverter size and battery array to higher loads also.

When in doubt, invert AC sign waves. Making it CA. It is much easier to power your farm with California power.

I'm sorry, but trolling was inevitable. Wouldn't you rather it be me than Randy?

[PulsedMedia]

Just my two cents.  I have done this before for a BBS I used to run(bout 20 years ago).

You get a 1200 Pure sign(169USD) wave inverter put a good power strip to it and plug in the computer. Connect the Power inverter to 4 12 Sealed lead Acid batteries(bout 180USD). At least 20Ah batteries. Then hook a good "automatic on" computer controlled charger and plug that to the wall(must be rated for sealed or AGX batteries).  Do not use regular car batteries as they will vent fumes.  I know it works and its pretty easy. Just keep in mind you will be 10% down on efficency on the power inverter(you gain some by charger not running all the time but it is negligible). So it will cost you more that plugging into the wall. You can adjust the inverter size and battery array to higher loads also.

That efficiency loss is why need to have something to switch.
HOWEVER, you could power your GPUs directly from the batteries, skipping the inverter step.
and then maybe utilizing a bunch of picoUPS: http://www.mini-box.com/picoUPS-120-12V-DC-micro-UPS-battery-backup
connected in parallel ... hmmph...

Run GPUs directly from batteries after regulators, where you have your 12V Gold/Platinum cert ATX PSUs supplying the main power, and a low voltage cutoff board, and picoPSUs supplying mobo power: http://www.mini-box.com/picoPSU-80
and splice in the loom 12V directly from battery pack, or use pci-e extenders where you splice-in from battery back, to ensure sufficient power.

Cost per system: 50$

hmmmph...

[PulsedMedia]

So drawing on this idea further.

Circuitry is something like:

WALL -> Trickle chargers -> Battery pack

WALL -> ATX PSUs -> Post Regulated Circuitry (Well call this power source circuitry or PSC)

Battery Pack  -> Regulators
                   -> Inverter


PSC  -> picoPSU Per motherboard
       -> GPU PCI-E connectors
       -> 12V to Mobo loom after picoPSU
       -> 12V to PCI-E extender
       -> Other 12V devices
       -> Tiny inverter for supporting 230V devices (ie. if router doesn't accept 12V, 230V Fans.)

Regulator circuitry is: Zener diode + Regulator per "lane", connecting in parallel to 2x1.5F caps.


Now tell me how friggin' dangerous is that setup

No PicoUPS even needed as pack is constantly being charged and 12V being supplied after the regulators. If utilizing PicoUPS then replace the regulator circuitry with them
ATX PSUs then connect to the bank of PicoUPS devices.

Hmmph... Time to build a proof of concept?

[rjk]

Hmmph... Time to build a proof of concept?

Be sure to use some old hairdryer nvidia cards for load testing, not your expensive radeons.

[PulsedMedia]

Hmmph... Time to build a proof of concept?

Be sure to use some old hairdryer nvidia cards for load testing, not your expensive radeons.

hahaha, was thinking
I still got some half broken AGP GeForces lying around
Also got plenty of prehistoric hardware for load testing

I guess adding several fuses, ie. 1 per card and zener diodes might be a good idea.

Has anyone enough electricity experience here and willing to tell me how to make the regulatory circuitry as efficient as possible?
and to make certain that a significant portion of the load does not come from the battery pack constantly?

Maybe utilizing picoUPS is not such a bad idea

[rjk]

Maybe utilizing picoUPS is not such a bad idea

I haven't seen any that are more than 10 amps each, are you thinking of using several in parallel?

[PulsedMedia]

Maybe utilizing picoUPS is not such a bad idea

I haven't seen any that are more than 10 amps each, are you thinking of using several in parallel?

Yeap, a bunch of them.
Yes, it adds a lot of cost tho :/

Maybe one can reverse engineer from one of them and swap the components up for larger ones