Is there any way to use a laptop battery with an ATX motherboard?

phisrow

Golden Member
Sep 6, 2004
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It could, in theory, be done; but not very practically. Most Laptop batteries are in the vicinity of 12 volts, so you could use them to run a standard automotive DC-DC power supply. You would, though, need to find a standalone battery charger compatible with the battery in question. Having the charger-battery-DC-DC converter-motherboard 'n stuff chain isn't so terribly elegant in the best of circumstances. More seriously, the last time I saw a standalone battery charger for laptop batteries was when I had a black and white passive TFT Thinkpad with a 386. The other real problem is capacity. I looked up a random battery on newegg (the first one that happened to come up was an 8800mah/10.8volt Toshiba device), which is probably representative enough. 8.8amp hours at 10.8 volts is only 95 watt hours. If we assume that your ATX device will, draw c. 150 watts the battery will be dead flat after just over 30 minutes (assuming perfect efficiency) lower drains would last longer, higher shorter, periods of time, of course.

Moral of the story: if this is idle curiosity, you might as well give up, it will be a pain. If this is some sort of robot project, you merely have to be clever. If you fancy a carputer, just feed off the car's power systems and address specific questions, at further length, to the enthusiasts on the subject.
 

Darkhawk28

Diamond Member
Dec 22, 2000
6,759
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Originally posted by: phisrow
It could, in theory, be done; but not very practically. Most Laptop batteries are in the vicinity of 12 volts, so you could use them to run a standard automotive DC-DC power supply. You would, though, need to find a standalone battery charger compatible with the battery in question. Having the charger-battery-DC-DC converter-motherboard 'n stuff chain isn't so terribly elegant in the best of circumstances. More seriously, the last time I saw a standalone battery charger for laptop batteries was when I had a black and white passive TFT Thinkpad with a 386. The other real problem is capacity. I looked up a random battery on newegg (the first one that happened to come up was an 8800mah/10.8volt Toshiba device), which is probably representative enough. 8.8amp hours at 10.8 volts is only 95 watt hours. If we assume that your ATX device will, draw c. 150 watts the battery will be dead flat after just over 30 minutes (assuming perfect efficiency) lower drains would last longer, higher shorter, periods of time, of course.

Moral of the story: if this is idle curiosity, you might as well give up, it will be a pain. If this is some sort of robot project, you merely have to be clever. If you fancy a carputer, just feed off the car's power systems and address specific questions, at further length, to the enthusiasts on the subject.

It was somewhere in between a robot project and you could say "morbid curiosity". I thought it was going to be a pain in the arse, but you pretty much confirmed my initial feelings.
 

3chordcharlie

Diamond Member
Mar 30, 2004
9,859
1
81
12 volts, built to power a computer specifically designed to use less power than a desktop.

Then you're going to run it through a converter (power loss), then another converter (PSU, BIG power loss).

No, even with a car adapter, you'd not be able to do it.
 

corkyg

Elite Member | Peripherals
Super Moderator
Mar 4, 2000
27,370
240
106
The voltage may be all that is needed, but the amps won't hack it. The average desktop has too many motors (fans, HDDs, opticals, etc.) and they draw current in addition to voltage that the laptop battery doesn't have. Hell - most laptop betteries can barely run the laptops (unless you have a mobile CPU.)