DIY HUAWEI R4875 70V~100V 0~50A 5000W

radio05

10 mW
Joined
Jun 15, 2021
Messages
30
This is HUAWEI R4875 charger I modified. The voltage and current can be controlled and adjusted by Bluetooth device. The modification process is difficult, but the final effect is satisfactory. This is much larger than 4850 power, can be 70-100V voltage arbitrary adjustment, 0-50A current arbitrary adjustment. Please do not post insulting remarks and racist remarks in my post, or you can only leave!
 
I use a 87.6V 40AH lithium iron phosphate battery pack, so in order to protect the battery and charge safely, the maximum charging current is only adjusted to 35A
 
Yes, exactly.
How it is modified, and what is is used to control it.

Do you know if the same can be done to the R4850G?
I have one of those that is modified so it can be adjusted to 120v (from 0 I think?)
And 0-25A with potentiometers. It is nice, except the fan goes full speed and is very noisy.
And I dont know how it is done..

I have some more of them, and it would be nice to be able to do something similar.
 
Looks like amazing high efficiency high power charger hardware for dry environment use. Would it be possible for you to offer them already modded or share your mod?

Huge respect to you for the clever reverse engineering and app control!
 
Bow down to your brilliance, that's twice the power and same size as what i use if not a bit smaller.

All the psu I've had still run like 15 years on subbed and super interested.
 
Theoretically, the 48xx can be controlled and can be adjusted through the CAN bus. However, this power supply has a shortcoming, which must be in the optimized voltage range to achieve maximum efficiency.
 
Starting from 0v is of little significance. This will seriously reduce the power efficiency. The original machine output 48-57v, which can be changed to 50-80, 60-90, 70-100, 80-120v, which can only run in this range, which can meet different requirements. The type, number of strings, and voltage of lithium batteries are charged and the capacity is calculated. It comes with a coulomb counter function. You can also check it through the battery management system APP.
 
If you are interested, you can contact me, Email: radio05@sina.com, Wechat: 17787134897, welcome to communicate with you, just to practice my English ability.
 
Ianhill said:
Bow down to your brilliance, that's twice the power and same size as what i use if not a bit smaller.

All the psu I've had still run like 15 years on subbed and super interested.

Thank you for learning from each other and making progress together.
 
liveforphysics said:
Looks like amazing high efficiency high power charger hardware for dry environment use. Would it be possible for you to offer them already modded or share your mod?

Huge respect to you for the clever reverse engineering and app control!

When appropriate, I will make a tutorial to teach you how to modify it.
 
Ive got wechat if you need to send anything.

Looks like a jikong bms is that communicating with the charger in can or is it just app controlled.
 
Ianhill said:
Ive got wechat if you need to send anything.

Looks like a jikong bms is that communicating with the charger in can or is it just app controlled.

BMS can use Bluetooth APP to control battery charging parameters, such as cut-off voltage, cut-off current, balance current, etc.
 
j bjork said:
Yes, exactly.
How it is modified, and what is is used to control it.

Do you know if the same can be done to the R4850G?
I have one of those that is modified so it can be adjusted to 120v (from 0 I think?)
And 0-25A with potentiometers. It is nice, except the fan goes full speed and is very noisy.
And I dont know how it is done..

I have some more of them, and it would be nice to be able to do something similar.

If the fan is equipped with a temperature control board, the noise can be greatly reduced. Mine is equipped with a temperature control board. When charging at 30A, the temperature is about 50 degrees, and the maximum can be charged at 60A, but my battery cannot accept such large current charging. So it has not been able to test the limit charging.
 
Can you do a list of hardware used and a few pictures if you have them of how you fitted it all.

Is the app a Wechat app or android ?

Thanks again for sharing your helping the community alot much appreciation.
 
radio05 said:
j bjork said:
Yes, exactly.
How it is modified, and what is is used to control it.

Do you know if the same can be done to the R4850G?
I have one of those that is modified so it can be adjusted to 120v (from 0 I think?)
And 0-25A with potentiometers. It is nice, except the fan goes full speed and is very noisy.
And I dont know how it is done..

I have some more of them, and it would be nice to be able to do something similar.

If the fan is equipped with a temperature control board, the noise can be greatly reduced. Mine is equipped with a temperature control board. When charging at 30A, the temperature is about 50 degrees, and the maximum can be charged at 60A, but my battery cannot accept such large current charging. So it has not been able to test the limit charging.

I dont know what is done to it to make it adjustable like this, but they sure has done something to the fan control too.
The unmodified ones I have has a very smooth fan control. It runs slow at first, then picks up a little speed as the psu gets warmer.

The modified one is pulsing the fan at first, so you can hear it goes up and down in speed. Then after a few minutes of charging it goes full speed, and stays that way until the amps go way down at the end of charge.

I use it to charge from 75-80v to 90v at 15-20A.

I can also use 2 of the unmodified in series, and adjust them with an external control board between 42 and 58v or something like that. The problem is when one of them go down to 40v to limit the amps it turns off.
 
j bjork said:
radio05 said:
j bjork said:
Yes, exactly.
How it is modified, and what is is used to control it.

Do you know if the same can be done to the R4850G?
I have one of those that is modified so it can be adjusted to 120v (from 0 I think?)
And 0-25A with potentiometers. It is nice, except the fan goes full speed and is very noisy.
And I dont know how it is done..

I have some more of them, and it would be nice to be able to do something similar.

If the fan is equipped with a temperature control board, the noise can be greatly reduced. Mine is equipped with a temperature control board. When charging at 30A, the temperature is about 50 degrees, and the maximum can be charged at 60A, but my battery cannot accept such large current charging. So it has not been able to test the limit charging.

I dont know what is done to it to make it adjustable like this, but they sure has done something to the fan control too.
The unmodified ones I have has a very smooth fan control. It runs slow at first, then picks up a little speed as the psu gets warmer.

The modified one is pulsing the fan at first, so you can hear it goes up and down in speed. Then after a few minutes of charging it goes full speed, and stays that way until the amps go way down at the end of charge.

I use it to charge from 75-80v to 90v at 15-20A.

I can also use 2 of the unmodified in series, and adjust them with an external control board between 42 and 58v or something like that. The problem is when one of them go down to 40v to limit the amps it turns off.
Switching power supplies are very dangerous to use in series. They cannot be used normally as chargers. Increase the voltage and reduce the current, and can operate safely within the rated power range.
 
Ianhill said:
Can you do a list of hardware used and a few pictures if you have them of how you fitted it all.

Is the app a Wechat app or android ?

Thanks again for sharing your helping the community alot much appreciation.

You can use Android APP or IOS APP to control the power supply, change and calibrate the voltage and current, and accurately count the charging capacity.dd
 
Hello everyone!
Seeing your messages, I know that everyone likes this modified power supply. There are kits and tutorials for this power supply modification, as well as finished products. I am currently considering whether to sell the modification kit or the finished product. This power supply is very good after modification. Wide application range, adjustable voltage and current, efficiency up to 97%, but there may be some tricky issues when it comes to cross-border transactions. I am also weighing these issues, and modification is difficult, such as disassembly and modification of electronic components. Because this power supply uses a large amount of copper to ensure the high current output of the power supply, it must be disassembled and assembled with professional tools, otherwise it will seriously damage the PCB circuit board or fail to disassemble some components, resulting in failure of the modification. If you are sure that you have rich experience and professional tools, I can sell the modification kit and provide you with free tutorials, but if you are a novice, it is not recommended to modify by yourself, I can sell the finished product.
 
The difficulty of modification is mainly due to the following problems:
1. Disassembly and assembly of transformers,
2. Rewind the transformer,
3. Disassembling and welding some SMD components, power tubes and filter capacitors.
Most of the modifiers failed in the first step. The transformer was dismantled and could not be restored. There was no replacement of the same type of magnetic core and the power supply was scrapped. Therefore, the risk of modification is high, and it is recommended to buy my finished product directly. After all, I have experience and can guarantee to meet your voltage and current requirements so that you can use it normally.
 
These are all lessons. The transformer was damaged during the disassembly process, which caused the subsequent work to be unable to continue, and the power supply was scrapped.微信图片_20210619004315.jpg微信图片_20210619004324.jpg微信图片_20210619004331.jpg
 
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