Question is there a PSU that input is 12v, instead of normal 120v/240v ?

[simonchad]

I want to power my pc with a battery that output 12V, like car battery or camping battery.
So I am thinking if I can just replace my usual PSU with one that intake 12v and output the usual PSU cables, then that would great.

EDIT: Just to clarify, I don't want to connect the battery straight into my motherboard / HDD / fan. I want connect the battery to 12vPSU, then 12vPSU to motherboard/HDD/Fan

 

[Grobe]

Maybe, but you'd run into the following problems:

• If a short circuits occurs on the 12V, the current from a battery can be much higher than from a PSU output and thus greater damage if that occurs.
• Voltage not regulated, and also the actual voltage for many batteries is > 13V while charging.
• If you run into emptying the battery, you don't know how the motherboard will react to that - I'll guess if mobo is well designed it shut down, but it's not how a normal motherboard is designed to be used for anyway.
• You still missing other voltages, like 5V and the connection between what should be the pc cabinet power button won't be functional so there will be issues starting up and shutdown.

So - without a special designed PSU for 12V battery input, this isn't going to work properly.

 

[NedSmelly]

Here ya go

Pico PSU
Powerstream
Sketchy eBay spaghetti

 

[NedSmelly]

A great thread here on Aliexpress clones of the Pico

HD-Plex 200W DC-ATX converter
Pico-Box

 

[Moonstick2]

This sounds like an XY problem. Why do you want to do this?

Let's say a typical non-gaming PC uses 80W on average, between idle and high load. Camping batteries seem to cost in the region of £1 / Wh, give or take. So £300 to be able to run the PC for four hours before having to recharge the battery.

Car battery capacity is in Ah. It might seem like e.g. a 75 Ah battery will give you over ten hours of running, but they're designed to deliver high currents for short times (hence using Ah not Wh), so I strongly suspect the efficiency when supplying a dribble current is much lower. (Otherwise why would camping batteries offer so much less capacity for the same price?)

So you're talking a few hundred pounds/dollars minimum of battery to run a headless (no monitor) ATX PC for a couple of hours or so. I'll bet that whatever you're trying to do, there's a much easier way to achieve it.

 

[NedSmelly]

Car battery capacity is in Ah. It might seem like e.g. a 75 Ah battery will give you over ten hours of running, but they're designed to deliver high currents for short times (hence using Ah not Wh)

Yep, if the OP is considering running their desktop PC off their car’s lead acid battery at a campsite then it’s a great way to sulfate it via deep discharge, and get stranded in the wilderness 🐻 Laptop, tablet, or 12V NUC seems more appropriate.

 

[simonchad]

Thanks Ned. The powerStream thing is what I am after.

I am thinking putting up few solar panel on my roof, save it to a power bank then draws it out at 12v
1) This way I don't have to deal with the connection to city grid.
2) 12v is pretty safe so maybe the power bank can be cheap and I can do the wiring myself
3) converting between 12v to 240v, then 240v back to 12v loses efficiency

 

[NedSmelly]

Thanks Ned. The powerStream thing is what I am after.

I am thinking putting up few solar panel on my roof, save it to a power bank then draws it out at 12v
1) This way I don't have to deal with the connection to city grid.
2) 12v is pretty safe so maybe the power bank can be cheap and I can do the wiring myself
3) converting between 12v to 240v, then 240v back to 12v loses efficiency

Sounds like a great off-grid project Good luck, do share your progress as it sounds really interesting.

 

[bill001g]

This tends to be something you see in business devices. This also means they are not cheap.
We used to buy DC power supplies for router and servers and they cost twice AC power for some reason....and HP and cisco already charge huge amounts for their stuff. This was 48 volt stuff that was used in telco rooms that only have dc power.

I have looked into doing something similar but the pricing of actual computer power supplies was so expensive I decided against a prebuilt solution. In the end I found that laptop was a easier solution an it already was dc based. I did need a dc/dc voltage converter since the laptop wanted 14 volts rather than 12 but I had the laptop for free.

The solar industry sell all kinds of these dc/dc power things that allow you to change the voltages. I am going to bet with enough effort you could build your own...you could just cut the wires off a old ac power supply and then be careful to get the correctly voltages on the correct pins. Mostly tedious soldering and crimping of wires and knowing how to use a voltage meter.

 

[Moonstick2]

3) converting between 12v to 240v, then 240v back to 12v loses efficiency

Whatever else the reason for you wanting 12V, efficiency isn't the right one. From a few places (e.g. this one), solar inverter losses are 97%. Paired with a platinum ATX PSU which is pretty much 90% across all loads, that's 87% net efficiency, whereas the PowerStream only gives 72% at full (1000W) load (presumably worse at lower loads).

 

[hotaru.hino]

Another problem I'm seeing is if this gaming PC is a high-end one with all the chops, then you're looking at around at least 400-500W all-in to power the thing at its peak. That's a lot of freaking current for 12V to handle.

 

[SyCoREAPER]

Find a low powered device that sells a power supply with car adapters. Or get a handheld like the Legion Go or ROG Ally and you can get a USB C adapter for dirt cheap on Amazon.

Since you didn't list your specs, I'll just broadly say, you're not powering your desktop with a 12v batt.

 

[stonecarver]

This is the kind of stuff I cut my teeth on making what others said " you can't do that " to um I already did !

When I was a teen mom always forgot to pay the electric bill. I took me about an hour to make life semi normal until power was turned back on.
I also pissed off the electric company than got an apology when the guy was leaving.

I took a black and white TV that was AC/DC powered. two car brake light bulbs and a car battery I put on the back patio.

Wired to the battery we were watching TV and I draped the brake light over the lamp shades next to the regular bulbs and we were in business.

I looked like a regular night just watching TV.

Than we got a bang bang on the front door it was the electric company demanding to have access to the meter in the back yard saying I was going to jail for tampering with there lock out. Five minutes later the dude tipped his hat to me and said sorry to bother you and shamefully left.

I have looked into those DC to DC converter and just so pricy.

The current aged me has full solar off grid that did run 4 gaming PC and the fridge during the sunlight off pure sinewave inverter and AGM batteries. And switched to grid power at night. And no I don't live in the stick but right in the city.

I moved but I have the whole system when I get to rebuilding the array.

The most important element of your project is after you work out DC to DC power supply or inverter to give you 120v for the PC is how your going to feed the battery to keep up with the demand.