High Voltage high current DC power supply

A

Alexanderfoti

10 W
Joined
Jun 18, 2016
Messages
78
Hi all

I recently found this on Aliexpress

https://www.aliexpress.com/item/3000W-Big-Power-0-90v-0-120v-Adjustable-Lithium-Battery-Charger-0-30A-Adjustable-Charger-for/32964180998.html?spm=a2g0s.9042311.0.0.1d504c4dCR8x2L

its a 0-120V 0-30A power supply, It has trim pots on the front to adjust both. It seems to be a modified Huwaei R4850G, which is nominally rated at about 50v, so they have been making some heavy modifications internally.

So far, so good, some pictures:




I am using this to charge my 26S leaf pack to 107.9V. Seems to work well so far, comes with XT90 connectors on the back, which I change to anderson connectors.

I bought two, so plan to charge at 6kw ish.

As I am using this connected straight to the pack, If anybody has any idea on how to accurately set the output to 107.9 (or something slightly less eg between 107.5-107.9) without spending big money on a fluke 289, do let me know!

Many thanks.
 
First: Nice charger!
Second: Too expensive for me :(
Third: Why a Fluke 289?
You can use some crappy Multimeter from eBay it'll do the job just fine, it's not like it'll be off by a huge margin or something especially when measuring DC.
 
Thank you. Its not too bad when you compare the alternatives for the power level I needed.

I also wanted something very small that would fit in the frame.

You say that, but a cheapo ebay meter on 600v dc range has an accuracy of 0.2% +- two counts, which means 100vdc could be 100.4vdc or 99.6vdc.... I think.
 
Just get an inexpensive one (not the cheapest) that can be calibrated, and borrow / rent a pricey Fluke to do so, near your target V.
 
I'm looking at a bryman 867 which has a 500,000 count display!! So 5-4/5 digits with a 0.03% + 2d accuracy which should be more than sufficient. Not too cheap but not fluke money either.
 
It can be iteresting to show modifications details. Because This PSU can be bought for $120 shipping included!
 
Everything is potted in the PSU, so I think it would be very difficult to reverse engineer without destroying it.

You could buy one to destroy but it would be expensive :)
 
I recommend the charger as well. I have it. Its pretty powerful. Just if you buy it, pay extra for shipping if you want it fast!
 
I would be suprised if it does the same thing at 120V ac, It will likely blow the internal fuse I would have thought.
 
I haven’t found a 120ac plug that can handle charging at more than 1500W dc. Most times I just do 1000w. I’m using 3x 500w 24v 120ac psus which I once saw go up to 2200w but now I see it is overkill. Used only at home now as it’s too heavy to carry.
 
There are modern 120V circuits rated at 20A, but most are 15A max.

And continuous draws should stay below 80% of rating, lower in an old house.

And that assumes no other loads on the circuit.

A big charge station area, worth getting the sparkie to out in at least one new 240V circuit, 50A or minimum 30A, as if for a large electric stove + clothes drier.
 
I was wondering 2 years down the road if you are still happy with this PSU/charger..

How has it been holding up? Because for its size to be able to deliver 0- ~2500w, 0-90v it seems amazing.
Never need another charger?
 
Until you get a reply from him I can say that I am pretty happy with mine.
I guess I have had it for almost a year or so, used it maybe 30-40 times.

The only complain I have is the fan is really noisy.
Soon after I start charge it goes full speed, and stays that way until it is almost finished and the current go down.
I have some unmodified huawei R4850G2, they are not like that at all.

I usually charge at 15-20A and up to 90V.
I have the 120V version.
 
So far, its still going well!

The fan is really really noisy, and even when its 5degrees C, seems to ramp up quickly.

I max it out at 25 amps @ 100v (240V input) without any issues.
 
I have run in to some issues with mine.
At first when I plug in everything it works fine, but after a while I notice it has stopped charging.

If I unplug the dc output I notice the output voltage has dropped. I started at something like 91V, and it drops to something like 75V I think. I can turn it up and try again, but the same thing happens. By then I run out of adjustment, and cant even get 90V out of the 120V it is supposed to be able to deliver.
If I wait a little and plug it in I can get the 120v again, and has to turn it down to 90v.

Anyone that has experienced something similar, or have an idea what it might be?
It would be nice if I could fix it..
 
Mine wont even start anymore, just used it once and now i have a expensive piece of junk.
Can somebody recommend some similar charger with atleast 90V 10A?

If someone want my broken charger (100V 30A) let me know.
Maybe you can fix it...
 
Alexanderfoti said:
Hi all

I recently found this on Aliexpress

https://www.aliexpress.com/item/3000W-Big-Power-0-90v-0-120v-Adjustable-Lithium-Battery-Charger-0-30A-Adjustable-Charger-for/32964180998.html?spm=a2g0s.9042311.0.0.1d504c4dCR8x2L

its a 0-120V 0-30A power supply, It has trim pots on the front to adjust both. It seems to be a modified Huwaei R4850G, which is nominally rated at about 50v, so they have been making some heavy modifications internally.

So far, so good, some pictures:




I am using this to charge my 26S leaf pack to 107.9V. Seems to work well so far, comes with XT90 connectors on the back, which I change to anderson connectors.

I bought two, so plan to charge at 6kw ish.

As I am using this connected straight to the pack, If anybody has any idea on how to accurately set the output to 107.9 (or something slightly less eg between 107.5-107.9) without spending big money on a fluke 289, do let me know!

Many thanks.
Click to expand...

Hello, does anyone know what modifications are needed to convert the original power supply output voltage to that range? I want an output voltage of 22.2V.
Thanks.
 
There were some vague posts in a Chinese-only hobby forum a few years ago. Definitely not a simple process.

You would need to buy the modded version and (likely pay an engineer to) reverse engineer the changes.
 
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