HP 3kW PSU - charging solution

Joined
Mar 25, 2010
Messages
258
Location
Columbus, OH
Ok quick intro. I mainly just browse and read on ES. Lot of great info. I am more active over on ElMoto.net. I have an electric motorcycle that I have upgraded to a 21s or 22s pack of lithium (3.7V) cells and will have 100Ah on board. I have been looking around for a charging solution for awhile now and the 3kW HP PSUs that liveforphysics first introduced were the cheapest and most powerful option available. So I bought 2 of the PSU and also 3 DC/DC (48to48) converters that Doc linked in his other thread. My plan is to have 1 PSU onboard (removable) with the 3 DC/DC. This gives me a 1.5kW charging system that fits on board if I need it. Then I will leave the other PSU at home so i can bypass the DC/DC's and run both PSU in series for a ~4 to 6kW charge on my 8kWh pack. Fortunately we had a hot tub that was run on a 220V 50A breaker so we are going to reroute this to the garage and I can have a nice "fast" charger setup at home :mrgreen:

Specs of PSU -
Output - 2950W, 51.4V, 57A
Input - 200-240, (but LFP has stated that it can be run on 110)
12.4 lbs (measured)
21.625" x 4.75" x 2.75" (measured)

Planned Mods
Voltage adjustment - Would like to have down to 45V if possible
Current limit - modify shunt or, more ideal, install a pot on the current sensing circuit to trick the current reading.
On/off switch - just involves shorting the right two pins from what I've read (think i know which pins to connect)

So what I need help with is figuring out these mods. I have located two pots internal to the PSU and will test them once I have a power cord created. Should I build an AC power cord with a 220V 30/50A plug and then build an adapter for that to a standard 110V NEMA plug? or vice versa?

Also which pin is which on the AC input?

Here are a bunch of random pics so far http://s194.photobucket.com/albums/z160/buckboom00/

I included a few of the PCB's and the pots I located on the boards
DSC02556.jpg

DSC02542.jpg

DSC02567.jpg

DSC02568.jpg
 
No 110vac luck on the 51v output models, only the 12v models.

Changing the voltage has been a major PITA.

What I've been doing is using a 50amp low voltage power supply in series with them. It gives you voltage adjustment and current control, and simple adjustability.
 
That is what I plan to do for charging 30s A123.
Two HP 3KW plus one ~5V current limited PSU in series for a total of ~107V.

Can somebody recommend a power supply with adjustable current limit in this voltage range?
 
liveforphysics said:
No 110vac luck on the 51v output models, only the 12v models.

Changing the voltage has been a major PITA.

What I've been doing is using a 50amp low voltage power supply in series with them. It gives you voltage adjustment and current control, and simple adjustability.

well darn...

Ok I think I might just have to buy a RSP Meanwell supply and use that to current limit. I was trying to stay cheap, but maybe i wont be able too.

Do you know what the two pots control on the supply?
 
Ok so after reading this thread http://endless-sphere.com/forums/viewtopic.php?f=14&t=29024 a little more closely I have decided to change my plan of attack a little bit.

I have purchased 4 more DC/DC 48Vto48V converters. So i will parallel 6or7 of these DC/DC up and series them with the output of one 3kW HP supply. I need ~90V so I will trim the output of the 6 DC/DC to be ~39V. The current limit on the DC/DC is 6A typical and 7.3A max.

The battery pack will want to draw the peak of the PSU at 2950W. Roughly half of this will be go through the 6 DC/DCs if we ignore inefficiencies. So 1475 at 39V out is 37.8A and is 6.3A per DC/DC. This is within the limits of the DC/DC converters so I dont forsee them being blown up, especially when losses and proper current sharing is calculated in. I believe I can get about 2400-2500W out of this setup. It will weigh about 14lbs and cost only ~$160, but will only work on 220V20A outlets.

I will use the other 3kW PSU that I have to maybe continue to work out the current trim or the voltage trim mods.
 
Any issues we should be aware of running a low voltage powr supply in series with these? Isolation or other issues?
 
vanilla ice said:
Any issues we should be aware of running a low voltage powr supply in series with these? Isolation or other issues?

You should place a humongous diode backward across the output to prevent it from getting reverse voltage from the others if it goes into limiting. Isolation is a must, but that is standard equipment on most supplies.
 
Running a 3KW power supply on 110V would be nutty anyway! You would need at least 30A!
 
heathyoung said:
Running a 3KW power supply on 110V would be nutty anyway! You would need at least 30A!

Very true, but if the PSU had a 110V input with limited power (say 1.5kW) it would making charging much more convenient. An on board charger essential doubles the range I can get round trip (stop in the middle to charge). Having 110V charging available would make that more possible. Charging at 220V at home and at school works out just fine and is really all I need for my daily commuting. I may get a Meanwell down the road for lightweight on board charging.
 
fechter said:
vanilla ice said:
Any issues we should be aware of running a low voltage powr supply in series with these? Isolation or other issues?

You should place a humongous diode backward across the output to prevent it from getting reverse voltage from the others if it goes into limiting. Isolation is a must, but that is standard equipment on most supplies.

Do i just rate a diode at the correct power out of a single DC/DC? So the DC/DC will be at 48V and maybe 7A max. Can i place a 50V10A diode across the + and - of each DC/DC blocking current from flowing from - to + (band towards the negative?)?

Edit: http://www.radioshack.com/product/index.jsp?productId=2062591 - would these work? OR two of these http://www.radioshack.com/product/index.jsp?productId=2062578

I understand the use of a diode, but have little experience with practical application.

FYI - 7 DC/DCs (7*250W = 1.75kW :))are being wired up and my 220v Plug has arrived. Hopefully I can power up the PSU later today!
-Kyle
 
Just in case anyone else is using this power supply I found a little more information on connections here: http://www.cnczone.com/forums/benchtop_machines/112634-hp_226519-001_3000w_48v_power.html
 
Some more information here: http://www.fixya.com/support/t8692410-about_hp_power_supply_part
including a link to the data sheet.
 

Attachments

  • datasheet-1.pdf
    1.3 MB · Views: 318
Just a note of caution, the PSU in the data sheet looks identical to the photos I've found of the model you have, but the pin arrangement for the small connectors may be different. I'd suggest using a 5k resistor rather than a jumper to test the enable connections first.
 
Well dammit. I was planning on using one of these in series with a meanwell for voltage adjustment and current limiting. To bad my house doesn't have a convenient 220v plug.

So what are the other options? Plenty of inexpensive 12v supplies, but it'd be a pain to put enough in series to get to ebike voltages. Any inexpensive and powerful 24v supplies?

I'm thinking no. There a few guides on making a 24v supply out of two server units, and the 3kw hp unit probably is cheap because it's only 220v.

Wish I could afford that power supply luke has with the variable voltage and current with the displays and adjustments on the front.
 
Alright - How about 4 of these in series. http://www.compuvest.com/Search.jsp?Search=24R2639&advsite=froogle&sku=155008942-82&dp=10:CVS:498:0:514

$5 each SHIPPED. Total power of 48v50a.

Edit: I just ordered and pared for two of them... lets see if they honor the free shipping and the $10 price.
 
I bet they will really ship them to you.

Datacenters de-com and throw out thousands of server power supplies everyday.


The trick with most of these supplies is finding one that can be turned on easily and without the server, and if it can just supply a bunch of random power without tripping etc.
 
fechter said:
vanilla ice said:
Any issues we should be aware of running a low voltage powr supply in series with these? Isolation or other issues?

You should place a humongous diode backward across the output to prevent it from getting reverse voltage from the others if it goes into limiting. Isolation is a must, but that is standard equipment on most supplies.

Can anyone elaborate more on this? is this the output of the PSU or the DC/DC.

A good link to read would be just as helpful.
-Kyle
 
Not yet... I've been extremely extremely busy.

It's on the workbench apart though. That means I will solve it.
 
Do you have any idea why they would make that connection port accessible by taking just the 2 screws and the little plate off??? I must be to adjust something.... I wish I could find someone at HP to tell us what it is for. Someone has to know or it wouldn't be there in the first place.
 
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