silverstone
Solar Enthusiast
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Yeah it's very weird. It does NOT happen MOST of the Time indeed. Or I'm just turning old and deaf or something 
DIY 'Chargenectifier'
- Thread starter 42OhmsPA
- Start date
For another flavour 4000w DC "Chargifier", here is a R4875G1 based GitHub esphome project.
github.com
GitHub - mjpalmowski/CAN-BUS-control-R4875G1-with-ESPHome-and-MQTT: Control one or more R4875G1 R4875G5 R4830G2 R4850G2 R4850S1 and adjust Current and Voltage Parameters on HUAWAI R4875G Battery-Charger via ESP32-hosted Web-Page, MQTT or Homeassistan
Control one or more R4875G1 R4875G5 R4830G2 R4850G2 R4850S1 and adjust Current and Voltage Parameters on HUAWAI R4875G Battery-Charger via ESP32-hosted Web-Page, MQTT or Homeassistant - mjpalmowski...
github.com
MakeMePower
Solar Enthusiast
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- Oct 11, 2021
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I know most of you are talking about 48v, but I did a 12v build with a HP Server PSU that does 75-100 amp
fmeili1
Solar Addict
Which option to choose? Does anyone have experience with both and/or made a comparison?
I'm most interested about noise level and reliability in practice.
Any experiences?
- Emerson R48-3000e3 (3kW, 96% eff., 42-58VDC/0-62.5ADC, <50dB noise, current limiting)
- HUAWEI R4875G1 (4kW, 97% eff.,42-58VDC/0-75ADC, <55dB noise, current limiting)
I'm most interested about noise level and reliability in practice.
Any experiences?
Noise: tends to be loud
Reliability: best you can get. These are used to keep critical infrastructure running and typically have mean time between failure rate measured in the hundreds of thousands of hours.
Which one to go for: depends mostly on what software support (if any) you need and how easy they are to get. I know the Emerson I can get for under 100 Euro including shipping.
Reliability: best you can get. These are used to keep critical infrastructure running and typically have mean time between failure rate measured in the hundreds of thousands of hours.
Which one to go for: depends mostly on what software support (if any) you need and how easy they are to get. I know the Emerson I can get for under 100 Euro including shipping.
Brucey
Velcro Man
Consider meanwell HEP-2400 if silent running (completely passive cooling with heatsink body) and reliability is critical. Not cheap tho.
fmeili1
Solar Addict
Oops, this is much more expensive -about 5x and with less power!
I don't think I will cosider this option because of the costs. But thanks anyway and good to know that completely silent options exists.
No Direct comparison, but I have two of the R4875G1s running daily in support of a Victron MP2 to charge my 48v LFPs at night. So far no noise issues, no heat issues (by design they do run pretty warm at around 70C operating temp so they can reject heat effectively in hot climates and that makes them very quiet at 25C ambient but they are rated for full output at much higher ambient temps). I never had them shut off on me. CAN BUS control is very reliable with an ESP32 each, automated via Homeassistant timer using hibernate/wake-up functions.
fmeili1
Solar Addict
Thanks for sharing these details!
Btw.
Do you know the differences between these R4875 models?
I found that the R4875G1 and R4875G5 both have 4000W (the R4875G2 has only 3000W).
Many stores offer now the G5 instead of the G1 but I can't find any difference.
The G1 and G5 use the same board edge connectors, so they are super similar at least. Also they use the same Can Bus control logic as far as I have seen.
fmeili1
Solar Addict
Thanks!
Now I think, I have a plan.
I want to get rid of my AC-in's for my 6 EG4-6500EX and would like to replace them with 4 DIY "Chargenctifier" based on the HUAWEI R4875G1 or G5 (depending which I'll get for less) to convert my system to a real double-conversion setup. I don't trust the bypass relays inside the AIOs about durability. Also I don't longer need to worry about small unwanted "backfeed to grid issues" and to eliminate the risk of the F60 error (Power feedback protection) which may sporadically happen just at the moment, when the AC-in's are connected to the grid.
I think about building two DIY cases, putting 2 of the R4875G1/G5 units inside each of these cases (both units with a PCB plug for the ease of connecting) and add just one ESP32 with two CAN adapters to remote control both units inside each case. I plan to place these cases right on top of both of my 2 battery racks and connect the battery cables directly to the busbars inside each server rack. Maybe I'll be able to find existing solutions for enclosures (mini racks, cabinet) with space for 2-3 of the R4875G1/G5 units vertical oriented - but nothing found so far...
The only theoretical limitation compared with using the AC-in's is the max. possible power over longer time. 4 of the R4875G1/G5 can "only" produce 16kW. My six AIOs are able to deliver a max. of 39kW. But I think in real life, this is not a problem because usually the batteries have at least a bit of charge (maybe plus PV at daytime) and my house consumption does usually not stay for longer times over 15-20kW usage.
Looks like the first "change / enhancement" of my current system will be in sight...
Yes, great way to isolate yourself from the grid without massive relays, especially if grid outages are frequent or your power company is giving you grief about feeding back power. You have huge inverter capacity so you don't need grid support and really only need the grid to keep your batteries from depleting. Btw you only need one controller for several R4875G units, you can just connect all the CAN lines in parallel as it is a BUS system. The (ESP32) could theoretically talk to individual units on the bus but the software I linked above is set up to give commands to all units. But don't worry they ramp up slowly when they wake up
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fmeili1
Solar Addict
Very useful information for me which makes it easier. I have never used CAN before.Btw you only need one controller for several R4875G units, you can just connect all the CAN lines in parallel as it is a BUS system. The (ESP32) could theoretically talk to individual units on the bus but the software I linked above is set up to give commands to all units. But don't worry they ramp up slowly when they wake up
I plan to split the 4 rectifiers into 2 different boxes and place them on top of my 2 battery racks and connect them directly to the busbars inside each battery rack. This will result in a (max.) 8kW additional power per battery rack. To add this power symmetrically, it would be better to control both rectifiers pairs with just one ESP32 to treat them as just "one" rectifiers unit.
I think I have two options.
1) I may just program the 4 rectifiers units once with my preferred absorption voltage (with max. current) and set it as the default startup output voltage. After setup, I can disconnect the ESP32 permanently and power on the units just with my existing (remote controlled) AC-in contactors. In this case all 4 rectifiers will automatically turn on with the same voltage/current settings, but no further control would be possible.
2) Or alternatively, I may connect the ESP32 permanently to all 4 rectifiers units to be able to change the voltage/current later while in use. In this case I need to place the ESP32 on top of one of the 2 rectifiers boxes and connect the other rectifiers box on the other battery rack "remote" via CAN bus cable.
I think option 2 is the way to go to be more flexible and have online monitoring with my existing MQTT environment connected to my OpenHAB system.
Btw. I've programmed some ESP8266/ESP32 with Arduino IDE (C++) but never used ESPHome. As far as I understand, ESPHome "programming" is done by yaml configuration instead of using a programming language (but never looked deeper into this). I'm not sure if I want to use 2 different ESP32 programming environments/systems - do you think it would be easy to transfer the yaml configuration to a typical Arduino C++ program with it's typical processing loop contract? Maybe the ESPHome environment have other advantages compared to the traditional Arduino C++ environment? I'm very flexible with the Arduino C++ programming and I don't know if I loose flexibility when using ESPHome. What do you think?
Noise is an understatement! Got mine up and running now, connected to v2l from my car to keep the battery between 60-80% which means I can use cheap electricity all the time I am home and my ASHP is running. I am trying to work out the fan control and if by adding either a secondary unit or just lowering the overall output or voltage can keep the fan to a reasonable minimum. When I get a chance I am also going to see if there are some decent alternative fans.
If you go to the lowest voltage (below 48V on the R48), the fan will be loudest. Reason being that this is where the current can be highest and P = R * I^2.
These things aren't made to be quiet, but they do need the airflow those fans deliver even though they're highly efficient.
Indeed but cheap high RPM fans are loud, I have a vain hope that a better high CFM fan will be quieter. I have spent a small fortune on Noctua 40s for my POE switches
I wouldn't call these fans cheap. These devices have a very high mean time between failure, and that includes the fan. But I'll be interested to know what you come up with!
I understand where you are coming from, I have ordered some random bits and will tinker when I can. Still waiting for my adapter to use your python script as well.
Agree, Option 2 allows monitoring and also access to the soft-on and soft-off, which avoids switching the power relays under full load when turning them off while the thing is charging at full output. If you want to try ESPHome outside Homeassitant, there is this
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fmeili1
Solar Addict
This is a very good point! I may do a 2-step for switching off, first soft-off the unit and after it's off, disconnect the AC-in contactor to also save the ilde consumption of the rectifier - I was not able to find the idle consumption of the R4875G1 or G5 in the datasheet, so I don't know if it's worth... but the contactors are there anyway.
Ok! Thanks for the video link which makes it very clear how to use ESPHome stand alone.
Idle consumption is near zero for my r4875g1s the fan is off and they don't get warm.. And leaving them in hibernate keeps the can bus up and you get battery voltage from the can bus and you can do local control using the esp as in the esp can call the charger if the voltage is too low. so you don't depend on WiFi to keep your batteries charged.
fmeili1
Solar Addict
I've looked a bit deeper into the code and try to understand some CAN bus details with this R4875G units (while getting more comfortable with the ESPHome YAML world - it's really different compared to C++ with the Arduino IDE).Yes, great way to isolate yourself from the grid without massive relays, especially if grid outages are frequent or your power company is giving you grief about feeding back power. You have huge inverter capacity so you don't need grid support and really only need the grid to keep your batteries from depleting. Btw you only need one controller for several R4875G units, you can just connect all the CAN lines in parallel as it is a BUS system. The (ESP32) could theoretically talk to individual units on the bus but the software I linked above is set up to give commands to all units. But don't worry they ramp up slowly when they wake up
Regarding the protocol spec of the R4875G (a link on the github page points to an Excel sheet with the details), up to 15 units may be attached in parallel to the CAN but. The document states, that each device (node) has it's own CAN address 0x108180FE for the 1st device, 0x108280FE for the 2nd, etc. If using 0x108080FE the settings will broadcast to all units.
But I have no idea how do I know, which unit will use which address? I can't find any hint about e.g. an address dip-switch to select the CAN address (1-15). I don't know how this is handled in the CAN bus world in general if you connect more than one identical devices to the bus. I've done some research and was not able to find an valid answer so far?
AI gave me the following answer:
But how can the protocol spec say that address 0x108080FE is for the 1st device, 0x108280FE for the 2nd, etc. but at the same time the AI answer says that there are no address fixed to devices? There need to be a way to identify the relation between the physical unit and the address.
Symbioquine
Solar Enthusiast
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- Jul 6, 2021
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I think the problem is clear - you're expecting useful output from so-called "AI". I don't know anything about this specific CAN address question, but I'd always tend to trust the spec ahead of most other sources.
fmeili1
Solar Addict
I usually don't trust AI answers - but often they point to a meaningful direction to help with own research. In this case, it's true that CAN protocol does not have fixed addresses for devices.
fmeili1
Solar Addict
I think I have a plan now to build an 16kW charger to convert my current system with AC-in's used by the AIOs to an online-double-conversion system!
I want to build 2 identical cases with 2 rectifiers each. One case will also contain the CAN controller (ESP32) and the buck converter to drive the controller. Each charger case should reside on top of my 2 battery server racks. The one CAN controller should control/monitor all 4 rectifiers connected to the same CAN bus.
This may be the CAN controller with it's PCB:
And the CAN tranceiver (which sits on top of the PCB as a sub-module):
The only open question for me is how to change the ESPHome program to distinguish between the 4 (identical) rectifiers.
I'm planning to integrate it via MQTT into my existin smart home system.
4x R4875G1 will be $440 (including shipping via ebay from China)
4x R4875G PCB connectors will be $50 (free shipping via ebay from China)
All in all, it should be possible to build it for about $600-$700 (incl. wires, T-fuses, cases, dbl. breakers, etc.).
I want to build 2 identical cases with 2 rectifiers each. One case will also contain the CAN controller (ESP32) and the buck converter to drive the controller. Each charger case should reside on top of my 2 battery server racks. The one CAN controller should control/monitor all 4 rectifiers connected to the same CAN bus.
This may be the CAN controller with it's PCB:
And the CAN tranceiver (which sits on top of the PCB as a sub-module):
The only open question for me is how to change the ESPHome program to distinguish between the 4 (identical) rectifiers.
I'm planning to integrate it via MQTT into my existin smart home system.
4x R4875G1 will be $440 (including shipping via ebay from China)
4x R4875G PCB connectors will be $50 (free shipping via ebay from China)
All in all, it should be possible to build it for about $600-$700 (incl. wires, T-fuses, cases, dbl. breakers, etc.).
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