Has anyone tried this??
 

We all know the new fermi is as power hungry as the city of Las Vegas. And it got me thinking, how can nVidia develop such a monstrous card if nothing can actually deliver enough power to show how much it can perform?? :banghead:

Then I got this idea:

The problem is getting enough power to the 480. It needs to be fed majorly by the 8 Pin plugs. Those plugs only deliver 12v, but the Amps are PSU limited. What's the next best energy source that can deliver that sort of voltage, yet having enough capacity to withstand a current draw like that...it can only be

A CAR BATTERY!!

Right now you might be just laughing you asses off on the ground, but think wisely. With a few electronics knowledge you will get this. :D

A car battery can draw as much as 1000 Amperes when a car engine starts, in order to start the alternator, at 9 volts. Because Power = Current x Voltage, that's 9000 Watts in 1.5 seconds. But it usually goes at 12.5 Volts supplying at max. around 100 Amps. That's more than enough, I guess. If not, get a truck battery. :rolleyes:

The best part is that it is dedicated to the GPU, your PSU would only have to feed the remaining components.

It just a case of getting the correct cables and plugs, connect them and voilá!

The disadvantage is that the battery would eventually discharge. But it should have more than enough capacity to endure a gaming session.

I haven't worked out the heating part...but someone will get to that...sooner or later...

Feel free to comment the idea.

Please note that I had this idea yesterday and haven't worked every little detail out. So something is bound to be missing. Yet it's an idea...

Wouldn't work, I'm afraid. A car battery can only suffer 1000A for a very short period of time, probably enough for you to see the bios before dying.

True, but I mentioned that.

Yet, you're suggesting a fermi would actually pull 1000A on POST?? Not likely.

Poor Fermi...It MIGHT work. Or, you might kiss your Fermi goodbye. Nothing (especially a car battery) can substitute for a good, high-quality PSU.

Contrary to popular belief, there are TONS of PSU that can power Fermi without issue.

Oh, the big car battery poster just blinded me D:

As interesting as the idea is, everyone can pull enough power for Fermi. 240V 13A fuse can withstand a bit more than 3000w, which is far more than what Fermi needs. Psu comes in 1000+w flavours, so no worries there either.

I have this unit in my garage..it's nothing but 100's of caps, basically trying to acheive the same thing...almost unlimited current.

In the end, all it did was smooth out the voltage.:laugh: You need to do serious mods for something like this...quite a few guys are hacking up motherboard PWMs to hook up to vgas...do some googling and you'll find what I'm talking about.

Hipro(Maximizer) and Shamino(mobo PWM on 9800GX2) are far ahead of ya on this one.

@ Fourstaff
Yeah, I know.

Still, I don't know what comes cheaper though...

I agree nothing replaces a good PSU...but a battery delivers DC and not rectified AC...
If you don't get a very high quality capacitors, there is always a small ripple.

Anyway, it was just an idea that popped up...

Yeah, my best man is an EE, and built up the unit. Cost about $400, and was a fun experience. At the time, line regulation was kinda poor from most power suplpies, so that was his idea to try to go farther..ebcuase of course, the cleaner the power, the better.

That's all a battery would provide, IMHO.

Another possible way was to take off load from the PSU...

Hence more power was available for the remaining components and one wouldn't have to resort to a 1000W+ PSU...could use a smaller unit...

I'm going to crap on this idea because a 750 watt could handle a 480 and i7 setup and be cheaper and easy to set up.

Agreed, but then we wont get cool pics of his pedal powered alternator;)

I think its more practical than a solar powered computer though like they did on tomshardware however.

Please have a link to this...checking Google now.

Edit: removed the link I found because the doctor is FAST!!

Geez, forget it then...

Ok, bad idea...I get it...

your typical car battery is rated a like 70 Ah -> 70 Ah * 12 V = 840 Wh

fermi draws ~250W in gaming -> 840 Wh / 250 W = 3.36 hours then your battery is empty

so how will a fermi based gaming notebook look like? :)

hey it's an idea, and interesting. that makes it ... not bad :) no one was ragging that much so don't worry about it...

keep thinking ;)

I would like to see this at a lan. Would be hysterical.

Sad. You guys seem to have little electronics background.

I actually RUN my computer on a car battery (rather 2) when the power goes out. I have 2 car batteries, one from my father's Camaro, and one from my car, both are somewhat in working order. Anyway, I have a transformer that converts the 12 volts (DC) to 120v (AC). How did I accomplish such a feat? Well I pretty much had one of those 12v to 120v converters built into a car I found in the junk yard. I took it. Works fine, rated to 700w. My computer and monitor together draw 600+w, so it is about right!

When I actually ended up using these batteries hooked up, fully charged, they lasted 2.5 hours (in parallel mind you) before I was out. Also, warning everyone, you cannot die from the car battery as is, you can touch your hands across the leads, but once you use a transformer like I did, you can die. Lets just say 1 hand behind your back is a good idea so the amps don't cross your heart.

After I finish my paper I can do some sweet calculations (theoretical, remember efficiency is more like 50% than 100%).

Solaris might be able to tell you more in the meantime... he is pretty good with electronics as well!

and don't forget a car battery holds alot more than 12volts (i've read some at 16 before :eek:)
so it would have to have some serious voltage regulation to not kill your card

plus you'd have to have some kind of link to the on /off green wire
novel idea though :D

Only thing is, he was talking about replacing the psu with the battery, not running the PSU off of a battery...which is widely available..they are called a UPS...right? :laugh:

I think he was thinking about PSUs with more than 1 12v line, where current/line is limited. This is obviously bypassed with a single rail PSU.

Of course, it's the vga's power delivery that limits any card...hence Hipro and Shamino taking the steps they have to deliver more power directly to where it's needed.

Yes, that was my idea. Single rail PSUs are harder to find here, hence the idea. The most common have 2 rails, like mine, and with rising price, also the number of rails rises.
I mean, most have one rail, but are then splited in two and have limiting circuits so excessive Amps don't ruin the regulators.

That was something I was unaware of. Thank you for pointing this! I will research it as I find it very interesting.

That would be very possible. I thought of a direct link for starters, but that could also be arranged. It just takes a simple circuit that included a transistor, to serve as the switch with the base liked to the ON LED with a resistor, a voltage regulator (with a massive heatsink to withstand the current), some heavy wattage capable low ohm resistors (to protect the circuit and GPUs from eventual current spikes), and possibly some other things that are missing, probably, because I still haven't given much at this.
If the transistor doesn't work, take a microcontroler to read the signals from the POWER ON switch and the ON LED and output a positive signal to a MOSFET gate. The MOSFET would connect, with source and drain, the batteries and the circuit I mentioned above.

It won't be a practical solution (by now) and I do recognize it wouldn't be a effective and cheap way to power a 480 (or more than one). But if it would work, I agree with Frick, it would be a center of attention in a LAN party.

Ok in that case this idea of his is just a great way to kill a card. Almost as good as the time when one guy wanted to do Tri-sli and split his mobo power connector into 3 parts, cause he wanted to power each card. Long story short, the thread go closed.

That's pretty much what people are saying. it works, but for a limited amount of time.

BTW, those converter things could be had for pretty cheap.