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Ramen Budget - LiPo/LiFe Charging Solutions

sshibly

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Good Morning from Sunny Balmy West Michigan!

In a previous thread someone mentioned HP server PS as being a cheap source of mega amps/watts.

I will list a few I found that worked with minimal work.
The PS alone is not the complete solution, I need a BUCK/BOOST CC CV converter to make use of the cheap HP Power.
BUCK Boost CC CV - I like the ones with built in display aka electronic control. The WATTS on these grossly overrated. I watched a few videos and was quite appalled. Count 8A to 10A as max.



HP PS

1. HP PL28 - 450W, $15 off ebay.
Max output - 12.3v

Mod - Short pin 33 and pin 36, Solder wires to positive /negative

Buck/Boost CC CV

1. Riden 6012/6015 etc -

This HP as a max of 12.3v, one PS will not work for Riden as they need the input volts be greater than output volts. You could put 2 HP ps in series and get 24.6v if you are handy.
20v x 15 amps = 300watts. In my books I would rather get a MEAN WELL LRS 300 series PS for $29 shipped as an alternate.

2. DROK 900W BUCK/BOOST that can utilize the high watts of the HP PSs


For $24 shipped this is a good value to use to charge your batteries.

The key is that it can boost the voltage and can take a 12.3v input and boost it to 100V or more.

3. DROK 3A

I really loves these to "BALANCE" my cells, I have 2 or 3 of these hooked up to to top off cells @ 2 amps.


Please add your solutions with prices.
 
Here is a pic of the mod for the HP PS,
I was struggling to figure out how to attach the wires to draw off it,

1. you can use a bent wire to jump the pins, I opted for a toggle switch $0.5 ( I bought 20$ off amazon)
2. I tinned the 12 awg first and made it somewhat flat and then tin the copper on the PS and soldered both together.
3. A XT-60 to finish off the end

To test it, I ran a 25A load and it ran fine.
 

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I recently purchased a couple HP HSTNS-PL11 for use with my ISDT Q8 MAX charger I also recently purchased. I quickly discovered the PL11 are very inefficient, noisy and not really necessary for my application. So I did the math and for less than $20 I went and purchased the latest Rev. of the HP HSTNS-PL28 (Part no.643954-201). The Q8 is good for 1000w and max of 30a/ voltage max of 33.3v. I was going to put two of these PL-28 's together and try and increase the voltage which with the 460 watt max output for each would get me pretty close to that 1000w max or 33.3volts I can push the charger. However there is no support out there for the PL-28 's. The "HACK" to increase voltage anyways is not out there. I tried to adjust the pot resistor on the daughter board and it unfortunately only adjust +/- .2v. I have yet to test the charger to see if it will step up the voltage with the input being lower. I'm assuming it has to match which means I need to increase the voltage on the PSU. Any information on how to do this would be highly appreciated!
 
Update:
If anyone is looking to purchase the ISDT Q8 Max, It does step up the voltage just at a small consumption loss. As you can also see in the photo I did a test of the PL28 at half load and it did perfect. Any where between 50%-75% is the most efficiency. With non professional data coming in from a wireless outlet I purchased from amazon, I was able to record a AC draw of 267.4W. I was receiving a 2.1amp loss between the power supply and the charger as you can see from the input voltage (11.2v) due to my 15amp jumper wires heating up. Either way I have presented some data.

Further information on the PL28, The voltage adjustment potentiometer @ 50% load 12.12v-12.20v (set point lowest-highest)

On another note if anyone was interested in the HP HSTNS-PL11 1200watt PSU. Here are the test results from both PL-11 and PL-28, Both same test charging, same voltage, same current, same equipment.

PL11
On with no load Consumption AC input 45.3w 407mA
Load:
AC Input 279.4w
Charger input 230w
Charger output 217w

PL28
On with no load Consumption AC input 4.3w 71mA
Load:
AC Input 267.4w
Charger Input 230w
Charger output 217w
 

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So ISDT Q8 Max will boost the voltage? nice.
HP server PS has OVP, the POTs can raise the voltage but OVP might kick in.
I am not sure if all models have the OVP.
Julian I did a few videos and he said the CAPS are rated for 16v so the max possible before the caps blow probably are go up in smokes.

12v hp PS + buck/boost CC CV is what you need. My cheapo DROK one does max 30v and 8 A for about $12

Can someone breakdown what is inside the ISDT Q8 Max?
 
You're right about the OVP and the 16v max on the Caps. However I was looking to either put two PSU's together and set them to 14.5v-15v and let the charger do the rest or put three together and set each to around 11v. I didn't want to use three mainly because of the waste of none needed power output from the PSU's and I will never really need but a few times in life the full 1000w out of either the PSU's or charger. Anyways, I will likely try the resister setup on the POT till I hit OVP, set it a little lower and then just let the charger do the rest of the conversion with just two PSU's in series.
 
You're right about the OVP and the 16v max on the Caps. However I was looking to either put two PSU's together and set them to 14.5v-15v and let the charger do the rest or put three together and set each to around 11v. I didn't want to use three mainly because of the waste of none needed power output from the PSU's and I will never really need but a few times in life the full 1000w out of either the PSU's or charger. Anyways, I will likely try the resister setup on the POT till I hit OVP, set it a little lower and then just let the charger do the rest of the conversion with just two PSU's in series.
I could not figure out what the input voltage range is for the ISDT, the specs are pretty vague.

Is the ISDT performing any cell balancing? if not I would skip it and set up voltage to 13.8v and charge our LIFEPO4 battery.
then use a smaller CC/CV to top it off or balance cells if needed.

Yeap, the big azz PSs are loud and consume a lot more idling,
 
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I could not figure out what the input voltage range is for the ISDT, the specs are pretty vague.

Is the ISDT performing any cell balancing? if not I would skip it and set up voltage to 13.8v and charge our LIFEPO4 battery.
then use a smaller CC/CV to top it off or balance cells if needed.

Yeap, the big azz PSs are loud and consume a lot more idling,
Input volt range of the ISDT Q8 MAX is 10-33.3 volt.

More info to come on the PL28
 
3 PS
2 float
put them all in series,
use a long azz cable to drop the voltage to 33v :ROFLMAO:
 
Alright, So I have done a lot of trial and error (It cost me a power supply!).
So for anyone that is going to use the HP PL28 Rev.15 and do the "FLOAT MOD". Isolation is very easy (removing -12v to chassis). If you are looking at the back where the edge connector is, right behind pins 33-38 there is the screw that holds the board to the chassis. That one screw is the only ground to chassis connection. So if you take out the screw and isolate the board underneath from the chassis using the plastic washers and plastic screw you are good to go on using it for a 24v-up system as long as you do it to each PSU, minus the MASTER.

As for voltage adjustment, I was unsuccessful to say the least. I was able to fool it and get it to output down to 11.88v up to 12.33v (zero load) and that's it. I did find a lot of other voltage's testing different components on the board. It seemed like it would just not go above that 12.33v, it seemed to just peg there at times while messing with different resistors. I just do not know enough to get these thing to work in my favor.

The last straw for it is when I accidently slipped with the probe and contacted a 15v lead to a .38v lead and it instantly fried one of the micro processors. It was actually still working afterwards up until I unplugged it and tried plugging it back in and it now just wont turn on! Oh well.. I have more on the way!
 
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So I just purchased some DPS-460MB (P/N 643954-101). These are interchangeable with the P/N 643954-201 mentioned above and they are also a Platinum cert. efficiency and have the hot plug. However they have a slightly different internal build. I'm pretty sure they are older units (given the part numbers). Hopefully they are easier to modify. Will find out in a week or so. I will do another assessment like I did with the last one.
 
If you have a 100W USB-C PD charger you can make a charger like the one I made in picture. It can charge at 60W from USB-C PD charger.

USB Trigger board set to 20V. I didn't want to solder so I went with one with screw terminals.

The buck converter set to CC 5A and CV of 13.55V (a safe float voltage). It is a bit oversize but as I intend to use inside of compartment I went larger to avoid overheating.

If you have a spare laptop battery charger you use that instead of USB-C trigger board. In my application I wanted USB-C PD charging.
 

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Alright, So I have done a lot of trial and error (It cost me a power supply!).
So for anyone that is going to use the HP PL28 Rev.15 and do the "FLOAT MOD". Isolation is very easy (removing -12v to chassis). If you are looking at the back where the edge connector is, right behind pins 33-38 there is the screw that holds the board to the chassis. That one screw is the only ground to chassis connection. So if you take out the screw and isolate the board underneath from the chassis using the plastic washers and plastic screw you are good to go on using it for a 24v-up system as long as you do it to each PSU, minus the MASTER.

As for voltage adjustment, I was unsuccessful to say the least. I was able to fool it and get it to output down to 11.88v up to 12.33v (zero load) and that's it. I did find a lot of other voltage's testing different components on the board. It seemed like it would just not go above that 12.33v, it seemed to just peg there at times while messing with different resistors. I just do not know enough to get these thing to work in my favor.

The last straw for it is when I accidently slipped with the probe and contacted a 15v lead to a .38v lead and it instantly fried one of the micro processors. It was actually still working afterwards up until I unplugged it and tried plugging it back in and it now just wont turn on! Oh well.. I have more on the way!

I just now realized it’s only the left screw on the PL28 that has contact with the DC board. Is the right screw just there for stabilizing the board? I do see a pad on the bottom but that’s the AC board (I think) and then there are pins on both sides that connect the lower (AC) board to the DC board.

Did you do a continuity check on the DC ground pad and the case to make sure you got it right? Have any issues since you’ve posted with the PL28? I did my first mod on two 460EB’s and then saw some MB’s for a great price and didn’t think they’d be different. Stupid me.
 
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