Rectifier Huawei R4850G2 48V 42~58V 3000w

[OhmSchool]

Thank you jairbj!! Problem now solved!! 8) 8)

I took off the rear adapter and connected AC voltage lines directly, and guess what...the power supply did NOT turn on, which is exactly the same situation as you reported. Logically, I started thinking the adapter must have some design error that is somehow causing the unexpected POWER ON behavior, and my testing described below confirmed this was, in fact, the case...the adapter has a critical design flaw! At least is does for the version of my power supply...R4850G2

I looked closely at +48v and -48v PCB traces on R4850G2, and I noticed the PCB design has changed (over time) compared to photos from other users that have previously been uploaded to this thread. Apparently, HUAWEI has changed the traces in the PCB from previous versions, but unfortunately the adapter that I purchased was not matched and suitable to the revised traces on the PCB.

I was able to find a simple workaround so I can still use the adapter, but also re-enable the START PIN function. I applied a KAPTON tape on BOTH SIDES of PCB traces on the power supply, actually on the top of the -48v traces.

After tape was applied, I reconnected the adapter to the power supply, and when I apply AC voltage the adapter works correctly. :thumb: To turn on the power supply is now very simple: GROUND only 1 of the 2 wires from the JST connector (the black wire). Note: Grounding the other JST wire (white wire) has no effect, so I leave it floating. The photo below will hopefully help others who have found this same problem.

Thank you again jairbj for your help and ideas, PROBLEM IS NOW SOLVED!! 8) 8)

 

[jairbj]

@OhmSchool

That's great I could help you.

Now I have a question for you? Are you wiring your PSU to 120vac or 220vac?

If possible, could you confirm that in 120vac it makes much more noise than in 220vac?

 

[kurik]

Hi guys, could anyone help me to decrease the output voltage of this rectifier please? I need it to be about 22V, instead of 42-58V.
I want to do it in a non expensive manner, that is, making some modifications, instead of adding an expensive external component that steps down the voltage.
Basically I want to obtain something like this
https://www.aliexpress.com/item/32964180998.html
But I don't need the voltage to be regulable.
Thank you!

 

[john61ct]

Better to just buy a PSU designed to output the voltage you want

Sent from my moto g power (2022) using Tapatalk

 

[kurik]

Better to just buy a PSU designed to output the voltage you want

Sent from my moto g power (2022) using Tapatalk

Thanks, but I need a 3000W power supply and a 24V PSU is extremely expensive, except this one (but it isn't of 24V).
Ideally I want 22.2V, do you know what could I do?
Couldn't I replace the feedback resistor of the PSU with a potentiometer to reduce the voltage?

 

[john61ct]

No idea, bit IMO very likely no chance.

The reason it's high power is because the high voltage keeps the current rate low.

Your desire to save money does not change the laws of physics

 

[dominik h]

There also exist 24V versions and a versions that can do both 24 and 48V called R24/4850N these can be voltage set via CAN.

 

[OhmSchool]

@OhmSchool

That's great I could help you.

Now I have a question for you? Are you wiring your PSU to 120vac or 220vac?

If possible, could you confirm that in 120vac it makes much more noise than in 220vac?

Yes thank you again jairbj for helping me find the solution!

To answer your question about noise:
I typically use 230-240vac. However because of your question, I conducted a special test to check the noise of my PSU at 120vac (25 amp DC load) and 240vac (25 amp DC load). I did not notice any difference in the usual noise, in fact it is very difficult to hear any noise from the Huawei.

By the way, I replaced the OEM 18,000 RPM PWM DC fan because it was giving off a very painful 60 dBA noise. I replaced the OEM fan with a SanAce 120mm PWM DC fan that only produces 45 dBA which is a very quiet wisper of sound (at least for my ears). For this sound test, I disconnected the DC FAN temporarily so I could listen to PSU very closely under both 120vac and 230/240vac conditions. So for my Huawei, no difference in noise between 120vac or 240vac.

I have experienced lots of trouble with noise from other PSU's (other than Huawei). For example, I have a Meanwell RSP-3000-48v. When I first purchased this PSU 6 years ago, it was very quiet with no problems. However over the years, the capacitors, inductors and coils have "relaxed" due to normal heating/stress of usage. In the last year or so, the Meanwell suddenly began giving off a very annoying high frequency piezoelectric noise, probably in 8 to 10khz audible range.

I was able to reduce most of the piezoelectric noise by applying damping glue (epoxy) to the surface of all inductors I could easily reach. I also did the same for the coils/transformers. The epoxy helped reduce the noise to something tolerable.

To diagnose and find the piezoelectric noise sources in the Meanwell, I simply touched the surface of inductors and coils with nylon tweezers to apply small physical force which immediately dampens the piezoelectric noise. Of course be very careful if you do this yourself, voltages in these PSU may seem small...however they can be very dangerous and PSU must be operating at high DC load to generate the piezoelectric noise.

Hopefully this helps you with your situation.

 

[dr_lulz]

Has anyone tested the CAN code for other models like r4875g1? I would prefer this model because of the 4000w but if CAN controlling does not work, its useless

 

[R4850S1_]

I tested the CAN code for r4850g2 on R4850S1 and it works

 

[Ianhill]

I been using a chargery 1500w 24s charger with a jikong active bms 24s 300amp and had good results only issue i had was the crappy wire placement out the case on the charger swapped that to anderson powerpole fitted to the case.

For me i don't want to go over 1500w max from the grid so i can still charge in asmany places as possible its no good been able to pull 3000w but the charger is to big to transport and even if it could its possible that it could overheat someone's electrics if its not a ring circuit, 240v 16amp for a kettle and 2-3mins can warm a cable, do that for hours at a time and it may cook some poor sods radial circuit that bob sparks and jack the lad signed off with hand on heart shes a gooden.

 

[rigmo]

Hi guys sorry for late replay. Im apologies because Im not often here And make this notice.
I still can get controllers directly if interested write me PM.

 

[hias9]

I want to set output voltage of my R4850G2 to 46.2V. (two in series to charge 22S)
The lowest default output voltage it accepted via CAN was 48.1V.

So I need a hardware mod or two of these external CAN boards.

Is there a way to solder a resistor somewhere to lower output voltage like it is possible on some other PSUs?
Does anybody still have some of those CAN boards?
@rigmo: I sent you a PM

 

[dr_lulz]

Today i was able to test CAN communication on my R4875G1. So far it works more or less out of the box. :thumb:
It pulls 4w standby. Fan is more or less silent. If current is set to 0A the voltage starts dropping slowly and the fan ramps up for no reason. Hopefully this changes with a battery attached.
Currently i am looking for some 50v discharge device because my 12V light bulb got fried in a test although the PSU was limited to 1A output current

Anyway, did you guys take care of L and N connection? Can i exchange those? Can i just mount a common household plug which plugs in both directions?

 

[j bjork]

Can i just mount a common household plug which plugs in both directions?

Yes, no problem.

The fan speeds up at low voltage and the psu resets if it goes too low, about 40V

 

[dr_lulz]

in case anyone cares, this is how my PSU looks now:

i soldered 8mm bolts for battery and attached screw terminals for 2.5mm^2 230v cables.
Hopefully enough for 70A for several hours

 

[dominik h]

The R4850G2 works down to 30V the fan goes to full speed under 40V. Test were done with 27A and 53V setting.
I will get a few R4875 in the next weeks and will test them with the electronic load.
I'm still working on a small an powerfull charger for my 21S100Ah Scooter. They will be put in series einher with a huawei or a megmeet 24V rectifier with 2kw.

 

[VK3AMP]

A little update on my PSU hacking attempts:

I love it, But I wonder does bluetooth penetrate the case when its closed, or are you not planning to close it?

Work in progress still, code on GitHub https://github.com/BotoX/huawei-r48xx-esp32
Using this lib for CAN on ESP32 https://github.com/sandeepmistry/arduino-CAN

I am taking a look at the sources, and appreciate the wonderful programming style!
Let me think, since this is CAN bus the controller really wouldn't have to be in the PSU, but could be - maybe sporting an OLED status display and even a rotary click switch for direct menu control be somewhere in the vehicle cockpit? Or even become part of code in any other MCU connected to that CAN bus? Do you require (other than the supply voltage) access to other signals in the Huawei rectifier?

I've put the ESP32 inside of the Huawei so it's self-contained and powered by the PSU.
The WiFi and Bluetooth work with random reliability, sometimes they both excellent.
Sometimes WiFi doesn't work at all but Bluetooth works fine.
And sometimes you have to get really close and wait a little longer for only Bluetooth to work.
You can put OLEDs and switches and whatnot, but I'm lazy and don't have to adjust it often, so bluetooth is fine.
And WiFi comes for free too so I can watch my battery charging on my pc with telnet lol.

The CAN pins are exposed outside too, see the other posts/images in this thread.
You can put multiple PSUs on the same CAN bus too and control them individually (with changes to the code).
You don't need anything else other than CAN bus.
However I was hoping that I could put the PSU into sleep mode and keep it plugged in at all times by turning off the output with that one wire. Turns out it uses way too much power in idle by doing that, real sleep mode is probably triggered with a CAN command that I don't know.

Here's some more code for the huawei psu communication: https://github.com/huyugit/om-miner/tree/master/sm-miner-slave/src/psu
This guy seems to be controlling multiple ones on the same bus.

What changes need to be made to the code to control 2 r4850 modules in parallel?

 

[OhmSchool]

What changes need to be made to the code to control 2 r4850 modules in parallel?

Wow, 2x r4850s in parallel? That would produce 56 x 2 = 112 amps DC and 42 amps of 240v AC current at full load. Curious to know what on earth could be drawing 6000 watts DC?? Hoping the cost of electricity is low in your area.

 

[R4850S1_]

I'm not 100% sure, but with my knowledge, I would put both r4850 in cc (constant current) mode so that they charge battery at the same current and I would set the upper voltage limit on both where the cc mode would end.

 

[dominik h]

The Huawei are made to work in paralell.
If you do not want to make live changes, you only have to set the offline max voltage on both to your needs. The rest will be done by the psus.

If you want to make changes on the fly I think you need two separated CAN Controllers. But i did not test this myself, as i have no need to change things often.

Under full load a 3kW Huawei takes 13.7A from a 230V line.

I ran a setup with 2 Eltek 2kWs in series and three of them in paralell to give me a 10kw charger for my scooter.

The next setup will probably be two 4kw huawei in series with two 2kW 24V rectifiers. That will be smaller and lighter.

 

[TIOK]

Hello.
Can you tell me how to change the settings of the CAN controller using a computer and a USB adapter?
Help who knows.

 

[dr_lulz]

Lately i have tested my r4875g2 for max power. Somehow i am not able to go above 58A
If i send the CAN command for setting current to 65A i end up with 1A or less.
At first i thought it is an integer overflow somewhere in the CAN code but the value that is send to the PSU is 58*20 = 1160, which is not close to any overflow
Seems to be related to 3000w @ 54V and 58A, but the PSU is 4000w? ....

Did anyone have the same problem?

 

[TIOK]

My R4875G1 only holds 60 amps too.
In the native controller SMU02B, the current is unlimited 121%.
What is the problem I do not understand.

 

[dominik h]

Same with my three R4875G1 , got them delivered today.

They act like they are R4850