The voltage will drop down but if I remember correctly it will only drop to 10.9-11 something.

Do you remember what should be modified to decrease the voltage ?

Did you follow my tutorial and float the DC ground on one of the units? And are both units powering on?

@@JoshMoenheli thanks for the reply, I figured it out and sent power out vs sending it to the slave psu.

So I swapped the power leads as direct and it still doesn’t work

After some more testing on the master I have continuity between + lead and the case

Which version do you have? Im trying to convert PD19 to 14.5v but not finding much solid information.

not possible

@@mikemorgan2733very possible lol these things are beasts as power supplies for linear amps

It can. This video was done before I figured out the solution. They don't turn on with a resistor bridging the contacts so you have to short them out instead. Then they turn on. There is an update video linked in the description of this video.

Yes. In the other video I go through connecting them in series and adjusting the voltage up as high or low as possible.

Unfortunately these supplies aren’t capable of going that high.

I left a link, but you deleted it!@@JoshMoenheli

​@@travis-c5o As of 2023 (I don't know exactly when), KZbin allows links to other KZbin videos but not to links away from KZbin. However, the poster of the video can include offsite links in the description below the video. I've had so many comments not post because of some reference that KZbin does not like that I now copy any comment I make to a text file so that I can try variants until I find something that will post. After I post, I refresh the screen to make sure that the post will stay posted. I have not been able to find KZbin's rules for what it does not allow in terms of references elsewhere. Even editing a post too many times will kill it.

Here are 13.8V mods for two models of the HP DPS-1200FB server power supply: kzbin.info/www/bejne/fGG0iISkqbWehZY

Hi @izzlate , did you ever get to the 3d printable case for this psu?

That is what this video is all about. Converting them so they can safely run in series.

If you plan to use them in series that is correct. This is an update to a video I published over a year ago. kzbin.info/www/bejne/mnWznmWfd8RpmZY

@@JoshMoenheli Ahhh, I guess I didn't realize you had this video out there. My apologies. I did my retrofit in like 2015. I'm not sure which fan mine has on it. Also not sure what the differences are between the two fans. I started watching these videos again after 7 years because I'm going to be using this power supply to bench test car amplifiers. So I wanted to see about voltage. Because car stereo amplifiers like 14.2 v. And the SPL (sound pressure level) guys push 15 or 16 volts. But one of the guys on the car audio group said 12 v. 70 A will be fine for test purposes.

So critical, he said that if you had watched the whole video, it was very good. We are all here to learn and support each other, I just bought this unit and wanted info on it and it was done very well.

@@DanielCValot it's not being critical, it's how electronics work. You learned something today whether you wanted to or not.

Ace Hardware, Home Depot, Lowe’s, any home improvement store should have them.

@@JoshMoenheli do you know the size?

I think I mentioned it in the video but I’m pretty sure they are around 6/32.

It depends. What is your power source? Car battery or dc power supply or something else?

@@JoshMoenheli DC power. Just a regular socket

@@PiTeRtrs Then you need to make an adapter to go from XT60 to what your power supply uses.

Without adding something external, it won't do it. the max I have ever been able to get out of any of these supplies that I have modded over the yeas is 12.3-12.5vdc.

@Josh Moen ahhh I've modded a few others and with a resistor I was able to get 16v but these ones are a little different...thanks!

sorry I just saw the other comments where you explain it, my mistake

No, the charger requires power to operate, regardless of the charge level of the battery. You could use a battery to power the charger if you wanted to.

I didn’t use anything crazy. I’ve used a 30-40 watt Weller soldering iron from Hole Depot. The key is to tin the jumper wire and pool solder on the contacts.

I’m not 100% sure about this charger but I would assume yes since it charges 6s batteries. My Q8 does this and so does my P30.

The issue has been that when I soldered the resistor across the two pins, it wouldn't turn on the power supply. I have since had luck with them and just shorting the pins out with a piece of wire and it turns on.

The two I had didn’t. I don’t know if they do now.

@@JoshMoenheli mine t8 it has, you need to scroll in charging screen during charging

@@estartermanual then that’s new.

@@JoshMoenheli August 2019 buyed. Never updated

@@estartermanual I bought 2 of them when they first came out so maybe 2016 or 2017.

The issue has been that when I soldered the resistor across the two pins, it wouldn't turn on the power supply. I have since had luck with them and just shorting the pins out with a piece of wire and it turns on.

I have a few of these power supplies (and variants of) and with a "1200FB A" power supply you can use a 1K resistor with success. If you use a 1k resistor with a "1200FB-1 A" power supply (blue socket) it won't turn on. You need a 330 ohm resistor and your good to go.

@@rcadtechnologies1573 so I would be good with the “blue plug” model and a 330 resister? Theses are half the price of the others

@@robaxelsson530 IMO yes. The 1200FB-1 A power supplies are a great value and are slightly more efficient than their counterpart 1200-FB A. I don't know what would happen if you mix two different power supplies to get your 24V output. 🤔 I prefer using two of the same to avoid possible issues. (probably wouldn't be any but I'm OCD 😅)

Thank You!

@Sten To answer this question properly I need to know a few things. 1. What cell count and capacity batteries are you charging? 2. Do you have a DC power source, if yes what is it? 2. What is your charging source in the field? Let's start there.

@@JoshMoenheli Hi, thanks for your reply. At home I have a AC power supply that delivers DC power. In the field I will use a DC field Lipo or Li-ion pack. I will charge 6S lipo's with around 1300MAH, nothing spectacular. I just can't find the big differences between those chargers. Hmmm.. What's your advice. Is one better then the other?

@@sten6537 Since you have DC power sources already figured out then I would go with the P20. It's a more powerful charger and will suit you well. The K2 can run either ac or dc but I never have liked the chargers that have this feature. They always end up running at about half to 2/3 capability when running on ac. They are good for the people that don't have DC power sources available to them. If I were in your shoes, I'd go with the P20. I hope this helps and good luck!!

@@JoshMoenheli Thanks!! One more question. Does this mean that you can plug a simple cable from the wall into the K2 since there is an build in PSU inside?

@@sten6537 that is correct. You can plug it directly to a wall outlet OR plug it into a power supply.

I’ve had issues tricking them into turning on. I’ve since found that instead of using a resistor you can just short out the pads with a small piece of wire.

@@JoshMoenheli is that the only difference? I already have 2 power supplies with the blue connector?

@@htx_rc4256 I believe so. Shorting out the pins has been working.

@@JoshMoenheli when you say shorting. you mean just use the wire soldered between the pins instead of the resistor right?

@@anothersummer2782 that is correct.

Hi @Shahzad, Sorry I didn't elaborate on it. There are a lot of factors that come into play here so I'll do my best to explain it. The P30 will output a maximum of 1500w, with the max per channel being 1000w. Theoretically what this means is if you are charging something on ch1 and it's using 1000w then you only have 500w available for use on ch2 totaling 1500w. What I said about not being able to deliver 30a per channel may not be entirely correct as I fly mostly 6s-8s packs I will never see 30a per channel, however, lets do some math and find out where that breaking point is. Using 4.2v per cell fully charged: 2s LiPo at 30a = 252w 3s LiPo at 30a = 378w 4s LiPo at 30a = 504w 5s LiPo at 30a = 630w 6s LiPo at 30a = 756w 7s LiPo at 30a = 792w 8s LiPo at 30a = 1008w If we take the 1500 watts that are available and split it in half that gives us a theoretical 750w available on each channel. This means we could charge up to a 5s pack at 30a on each channel but when you reach the voltage of a 6s pack at full charge, that ends up going just over the 750w. Now, you could charge up to 1000w on one channel so in that case you could charge a 7s pack at 30a(with some spare wattage) on one channel and then a 5s LiPo on the other channel put the total charger output around 1422w. Again this is using the voltage of 4.2v per cell which is fully charged. This all varies depending on the voltage of the battery you are charging. In your case of only getting 20a per channel is most likely because the input voltage is stopping the charger from it's full potential. Get 24v going into the charger and you''ll see different results. I hope this helps! Thank you for watching and asking questions!

@@JoshMoenheli thanks. Indeed, it turns out the charger has a max input current of 60A, which isn't well advertised. My car outputs ~12V after losses. 60A x 12V= 720W available. The charging voltage of a 8s Lipo is ~17V => 42A max charging current when charging 2x 8s Lipos. This number tallies neatly with the charge current shown, taking into account losses/efficiency. It looks like I'll have to satisfy myself with this figure, unless I want to spend big money on a high current voltage inverter for my car to up-convert the voltage. 🙂

The app will show multiple devices but not all the channels of all the devices at once.

This is a complicated answer. If you read the specs closely, they state that you can charge 30a per port but at a max of 1000w and only 1500w as a total meaning you'd only be able to charge an additional 500w on the other port. Now that said, that is still a whole lot of power! So yes you can but it is totally dependent on the battery capacity and cell count. In theory, if you had three 5000mah 5 cell lipos in parallel on one channel you could charge at 2c which would be 30a and that would around 630 watts total. With this setup, you'd be able to charge 30a on each channel because your total wattage is 630 watts on the port and still under the 1000 watt maximum allowed on the port. You are also still under the 1500 watt maximum of the charger since you are using 1,230 watts total. If you were to charge three 6s lipos in parallel on each port at 3c the charger would top out at 30a on one port and about 28-29a on the other port. A 6s pack at 30a is around 756 watts which leaves you about 744w of wattage to use on the second port. As far as a power supply is concerned, that will also depend greatly on how much wattage you anticipate needing and adding 20-25% as a buffer.(If you plan on using 1500w I'd get a 2000w power supply.) I hope this helps.

Hi Mike, if you go here: www.isdt.co/support?lang=en and download the ISD Go software for PC, install it, connect it to the charger it should recognize the charger and search for the firmware. Otherwise there is always the option to do it via your phone or tablet over bluetooth.

Hi Vitor, for 2s packs you can get by just fine with a 12v power supply. I use server power supplies like these: www.ebay.com/sch/i.html?_from=R40&_nkw=HP+DPS1200-FB&_sacat=0&rt=nc&LH_ItemCondition=3000%7C2500 They typically cost around $50USD to as much as $100USD. I then trick them into turning on and outputting 12v. This mod is widely done and easy to do if only going 12v. To do 24v it's a little more work but not that bad. You can also get breakout boards that do the mod and give you terminal outputs. If you want a ready to go solution check these out: www.buddyrc.com/collections/power-supply/products/ep-buddy-900w-75a-12v-server-power-supply?variant=30274505506902. For a in the field solution I'd just charge off a 12v deep cycle battery or a vehicle battery. I hope this helps!

They show up next to each other. You can't control them both at the same time as in setup a cycle on one and it carries over to the other one but you can operate both from the app. That said, I haven't tried that as I only have the one but my P30 shows up in the device list next to the discharger and I can select either one.