Desktop PC run direcly from DC source?

[ArdentAngel]

Could anyone at @LMGcommunity @LinusTech test any of the acclaimed DC-DC conversion power supplies (yes, I know they kind of falsely advertise this after only using this in their internal design while they are still actually AC power supplies) or attempt to actually wire 12V source directly to this 12V DC rail?

 

By "false advertising" I mean listings like:

• MSI MAG A650BN Power Supply, 80 Plus Bronze Certified, ATX Power Supply, 12V Single-Rail, DC/DC Voltage Converter Design
• Tacens Radix ECO X 550, PC ATX Power Supply 550W, SMD and DC-DC Technologies
• Mars Gaming MPIII550P, PC Power Supply ATX 550W, DC-DC and SMD Technology

I mean, @LinusTech, you made that best gaming van, why didn't you consider plugging your PC directly to 12V source? (or did you consider and the idea just wasn't feasible in the end?) Having DC-AC inverter where you lose 10-15% energy due to efficiency just to convert it from AC to DC again where you again lose 10-15% due to the next conversion efficiency seems a lot less gaming for a pointless reason from the physics side of things (not that I'm a specialist in physics).

 

Just imagine the possibilites with a setup having a direct 12V source:

1. Off-site, off-grid remote location backups connected to solar-charged 12V batteries (connected to internet via a mobile network or Starlink or maybe to point-to-point connections you've setup in the past!)
2. Fully decked desktop PCs even when on trips, again charged with portable solar panels when the engine/generator isn't running, or maybe even roof-mounted flex solar panels!
3. Off-road work for designers, photographers, video-recorders & editors! True mobile studio with at least 20% better energy efficiency! Sure, it might not appear as much at the beginning, but if you want to go solar/independent, 20% CAN BE A LOT!

Anyway, what does the rest of the community think? Am I the only weird-one-out for considering something like this?

[Electronics Wizardy]

There are a few ATX PSU's made to run specifically off DC power. That seems like a much better idea than trying to hack a normal PSU to make the other rails you need. Also I'd typically not want to run a PC from 12v sources like batteries or alternators directly, as those can easily be out of spec voltage and ripple wise. For example a 12v lead acid battery can be at 14.4 volts in its charge cycle and well out of spec of the ATX voltage ranges. Also things like ripple can be worse than the PS wants.

[ArdentAngel]

Hence why I were asking if there is anything like that available. The only thing I could find are things like PicoPSU, with the highest voltage currently available (at least as far as I could find) being 300W. How reputable it is, I have no idea.

 

Where could I find such ATX PSU's? Because I tried manually looking and also using AI searching. No luck (besides PicoPSU).

 

Let's assume 550 being a target - I'd like to connect my NAS (desktop PC with TrueNAS) to it which at the moment uses 100W while idle (6x 20TB Seagate Exo HDD drives and 4 SATA SSD drives at the moment with SAS card). But since it is i5 13600K and I might install an additional GPU somewhere down the line...when not idle, power consumption might go higher.

 

Has anyone ever tried wiring them in parallel (PicoPSUs)? Does anyone know how it "turns on" to turn them all on at the same time and maybe power other devices in computer from the second one instead of wiring them in parallel directly?

 

Also, making a module to "clean-up" the 12V voltage before going to the modified power supply isn't out of the question and shouldn't be hard. I never said how to achieve anything, only stating the final goal: powering a full-blown desktop PC from a DC source - and the findings I've been able to find.

 

PS: You are right, I never mentioned I tried finding actual DC ATX power supplies...

[porina]

PicoPSUs were popular for low power ITX builds around 10 years ago. Don't know what they're like now. I still have a 160 XT somewhere. It takes in regulated 12V and is rated for 8A continuous, or about 96W, and they recommend air cooling for that. It can take short peaks of nearly double that. Looks like the 12V rail is switched to comply with ATX, but otherwise it doesn't do anything to it. The converters generate the 3.3V, 5V, 5VSB and -12V rails.

[Electronics Wizardy]

35 minutes ago, ArdentAngel said:

Hence why I were asking if there is anything like that available. The only thing I could find are things like PicoPSU, with the highest voltage currently available (at least as far as I could find) being 300W. How reputable it is, I have no idea.

 

Where could I find such ATX PSU's? Because I tried manually looking and also using AI searching. No luck (besides PicoPSU).

 

Let's assume 550 being a target - I'd like to connect my NAS (desktop PC with TrueNAS) to it which at the moment uses 100W while idle (6x 20TB Seagate Exo HDD drives and 4 SATA SSD drives at the moment with SAS card). But since it is i5 13600K and I might install an additional GPU somewhere down the line...when not idle, power consumption might go higher.

 

Has anyone ever tried wiring them in parallel (PicoPSUs)? Does anyone know how it "turns on" to turn them all on at the same time and maybe power other devices in computer from the second one instead of wiring them in parallel directly?

 

Also, making a module to "clean-up" the 12V voltage before going to the modified power supply isn't out of the question and shouldn't be hard. I never said how to achieve anything, only stating the final goal: powering a full-blown desktop PC from a DC source - and the findings I've been able to find.

 

PS: You are right, I never mentioned I tried finding actual DC ATX power supplies...

How about this? https://hdplex.com/hdplex-500w-hi-fi-dc-atx-power-supply-12v-48v-wide-range-voltage-input.html

 

I think there are others out there, found this on google.

[ArdentAngel]

Yea, just found the same thing a little while ago myself (was looking at the 800W model). Though a bit pricey, considering how it works (less conversion, hence less components involved, so price should have been lower than classic models, especially the 800W model, priced at more than 300 USD), so I'm still looking for possible alternatives.

 

And I'd still have to make 4-pin MOLEX cables/adapters myself, since it doesn't have those.

 

Though on the plus side, I could upgrade to 24V or 48V batteries anytime I wanted and I wouldn't have to search for anything new. The biggest thing holding me back is the price of 800W model (it being more future-proof).

[jaslion]

45 minutes ago, ArdentAngel said:

especially the 800W model, priced at more than 300 USD), so I'm still looking for possible alternatives.

Very low volume hence the price. Same with all the other direct actual dc to dc stuff price is HIGH for quality stuff.

[ArdentAngel]

Well, I understand. Then let us first go back to the original way I was going for (and leave the expensive one as a last resort).

 

We take Victron Energy Orion IP20 24/12-Volt 70 Amp DC-DC Converter Non-Isolated (for instance) to regulate our current from 2 LiFePo4 batteries connected in parallel for 24V and channel this regulated 12V output voltage directly to our classic ATX power supply's DC-DC 12V rail. Which should work. Total cost? 150 EUR. What do you all think?

 

Also @pixo95 and @treefroggy, if you still get notifications, have you managed to complete the project you started in your old thread?