Low Amperage using ATX PSU for Charger

Goofy

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I'm trying to use this PSU to use with my HiTec X2 however it errors out indicating low amps when trying to balance charge 2 LiPos at 8A each.

I grabbed 12v from one of the PCI-E cables (verified with a multimeter), so I'm not sure what I'm doing wrong here.
PXL_20221215_214800610.jpg
 

Goofy

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Don't use the PCIe power cables. Use the 12V main board connectors. According to that plaque you should have two that are in a single 4-pole aux connector. Mine is labeled P1 or P4. It's a bit smudged.
Ahhhh, will try this.
If memory serves me right, one of the supply pins needs to be grounded in order for the supply to be functional.
Should be able to google it. It's not vendor specific.
Yea, I've got a jumper so the PSU is working when I turn it on.
 

Diem Turner

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If memory serves me right, one of the supply pins needs to be grounded in order for the supply to be functional.
Should be able to google it. It's not vendor specific.
Yeah, you have to short the green against one of the ground leads of the ATX main connector. Then you're good to go.
Ahhhh, will try this.

Yea, I've got a jumper so the PSU is working when I turn it on.
Godspeed and good luck! Hope that works out for you :)
 

Goofy

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Yeah, you have to short the green against one of the ground leads of the ATX main connector. Then you're good to go.

Godspeed and good luck! Hope that works out for you :)
To correct my OP, I'm 90% sure I have the correct rail(s) and am measuring DCV correctly. On the DMM, I have black in the COM port and red in the VΩ port. I'm showing ~12.4V on both of the pictured plugs, and they're the only 4 pins coming out of the PSU. Do I need to grab 12v from the +4 on the mobo 20+4 connector?
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Diem Turner

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To correct my OP, I'm 90% sure I have the correct rail(s) and am measuring DCV correctly. On the DMM, I have black in the COM port and red in the VΩ port. I'm showing ~12.4V on both of the pictured plugs, and they're the only 4 pins coming out of the PSU. Do I need to grab 12v from the +4 on the mobo 20+4 connector?
View attachment 262968
This is how I hooked mine up. In the middle you can see the 20+4 ATX connector for the motherboard. And behind it there's another 4-pin connector labeled P4, which consists of either one or two 12V rails. The P4 was introduced back in the day for motherboards that supported Pentium-4 and later Intel CPUs. They were subsequently used to feed power to both Intel and AMD processors as far as I know.
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Goofy

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So I've tossed a 10W/10ohm resistor on the 5v rail as some others have suggested as well as trying to charge two batteries at once; One 12v rail per charger. Same dealy, I get close to 8A on both and then each charger errors out with low DC Input voltage.

Is this PSU just hot garbage? :(

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jkflow

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I doubt it, probably yet another safety feature. No idea what version supply you have, might just be something newer/polder than what others are using.
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RedOctobyr

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Just saw this thread, but I'm afraid I don't have any suggestions beyond what has been mentioned. The last time I used a standard PC power supply for a charger, it was an AT supply, not ATX, so it's been a while :shame:

But just in case it maybe helps someone else, at least, have you considered a used server power supply? I have a few HP DPS-600PB server supplies, 12V, at 47A. They are built for high outputs of 12V. Here's one for $23 shipped on eBay, as an example:

https://www.ebay.com/itm/284168191718

They can also be joined together in series (you have to modify one supply, to float the ground), giving you 24V, 1150W.

There may well be better server supply options these days, but these were popular when I was trying to find an inexpensive, powerful supply for my charger.
 
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