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Stronger PSU wanted
#1
Hi all,
My psu now in use is a good one, but with 40Amp at 6.2v it does not meet my demands anymore.
Its rated for 30amp and the voltage is dropping like a brick when i ask more then 45Amp.
Its a heavy stabilized one.




Those cheap? psu's from ali, arent those just pc psu's?
If so, i have some of those (counting up to 850w at 5v), some capacitors on the line, ill it smooth out the path?
Or just buy a new stabilized one?
And for what to look for?

My wish is a minimum of 60A at 5v

Recommendations are appreciated, thanks in advance
Still learning English. Learning Li ion and solar technology.
+/- 3500 Li ion cells harvested, none checked and counting.

Time is our enemy, must work to, the sun is our friend, must relax to.
With best regards
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#2
Why do you need a single large PSU ?
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#3
(05-07-2019, 07:03 PM)Sean Wrote: Why do you need a single large PSU ?

I think he wants to charge/discharge 60 cells at a time with 1 PSU. Tongue

Looking at his charging board it seems to indicate that.

Personally I would split the board to be supplied by 3 30A PSUs 

Wolf
If 18 X 650 = 2200+mAh then we have power! 
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Cells ≥2200mAh & ≥ 80% & ≤75mΩ    2593 (207) to go
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#4
Use PC PC PSU's, the 5V rail has heaps of current.
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#5
(05-07-2019, 11:35 PM)Redpacket Wrote: Use PC PC PSU's, the 5V rail has heaps of current.

Or even use the 12V rail and put some buck converters in line. Or even use the 12V rail with TP5100's. Save a lot more $$ than buying a large Amp PSU
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#6
(05-08-2019, 01:01 AM)Korishan Wrote:
(05-07-2019, 11:35 PM)Redpacket Wrote: Use PC PC PSU's, the 5V rail has heaps of current.

Or even use the 12V rail and put some buck converters in line. Or even use the 12V rail with TP5100's. Save a lot more $$ than buying a large Amp PSU

This. Use a server power supply with a high current 12v out. Then several bucks, or use the TP5100. Sounds over complicated, but you won't need such heavy gauge wire. Also server power supplies are readily available secondhand, at good prices.

RCGroups have a comprehensive guide on how to wire one to turn on.
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#7
PC PSUs now-days are no longer too powerful on the 5V rail. They are designed with 12V rails in mind. Those are made to withstand most of the total PSU provided power, since both CPUs and video cards are powered-up like that (via 12V).

5V remains for low power devices like notebook HDDs that don't need/use 12V.

So no, a PC PSU will not do on 5V. The voltage drop will be very high, making you hit 4.2 with even as low as 6 charging cells that demand good current.

For me, I use sources like SP-200-5 +5V/40A MEAN WELL . The provided voltage is good even at very high current, nearly no drop.

In your case, you could go for something like PSP-600-5 +5V/80A MEAN WELL, which is rated 80A. I'm sure there are more brands available with even higher max currents.
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#8
I would go 12V server psu. Server psu with 12V as main they can easy supply 1-2kW of power and then use a buck converter down to 5v. Thats most likely the cheapest option i recon.
A 1kW psu like that cost 30USD
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#9
@Wolf,
Yes i would like to do 30 at the same time charge and discharge, but there is a other charging board also connected.
That board charges 10 cells extra every time and has a voltage regulator to charge the discharged cells to 3.5v for storage.
So the units come in handy after all, just pick m up and put them in a other bay.
For the third board that is connected is for sleepers and some testing.

First board 30 x 1 amp plus 30 x 0.07amp = 32,1 amp
Second board 10 x 1 amp and 1 x 10amp = 20 amp
Third board 1 x 6 amp and ~ plus 3,5amp = 10 amp
In this setup my wife and i are doing a 90 - 120 cells a day, fully tested and they had there 4 weeks waiting time.

You're idea to use 3 psu's is not so bad.

Problem with the pc psu is that they are not stabilised, if i recall, you need a 1000uF for every amp you use, right?

So the capacitor on one 20amp 5v line (got 4 of them out some slimeline pc's) will be 27000uF at 16v? those capacitors are also 7 euro.
Or buy one really big capacitor 82000uF at 16v-100000uF at 25v? and connect all 4 psu to it?
All the units seems happier with stable power.

Why am i doing all this trouble? This whole process is not stopping for the next two years, i guess.
I also send a email to meanwell (and philips), for a big 5-6v 80-100 amp psu, the biggest one i could find was, i belief 40amp at 5v

Thanks in advance
Still learning English. Learning Li ion and solar technology.
+/- 3500 Li ion cells harvested, none checked and counting.

Time is our enemy, must work to, the sun is our friend, must relax to.
With best regards
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#10
@ 100kWh-Hunter

Yes you could use a LRS-200-5 40A and a LRS-350-5 60A and split their outputs accordingly to feed all your boards.
With a Ripple & Noise rating of 150mVp-p I dont think any additional capacitors are needed.

Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 5/19/2019
Total Number of Cells                          5335
Cells  >80% of Capacity                      3744
Cells <80% of Capacity                       1546
Cells ≥2200mAh & ≥ 80% & ≤75mΩ    2593 (207) to go
For Info Google Drive
Not your average Wolf       
            Cool



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