DIY 'Chargenectifier'

[kta22]

Hello everyone,


I have implemented an ESP32-based controller for the Eltek Flatpack2 with Home Assistant integration(https://github.com/taHC81/Eltek-Flatpack2-ESPhome). The setup has been working well for voltage and current control. However, after connecting a 2kWh Li-Ion battery (~41V), the PSU functioned correctly for a few minutes before shutting down. The cooling fan stopped, and only the power LED (green) is flashing.


Currently, the unit is not providing any output voltage, and the CAN bus communication is sending only zeros. Could this indicate that the unit has entered a protection mode? If so, how can it be reset? Has anyone encountered a similar issue?


Any insights would be greatly appreciated.

 

[fmeili1]

I don't know anything about the Eltek Flatpack2 (I'm using Huawei R4875G1) and I'm not sure if I can really help, but after looking to the spec sheet of the Flatpack2, there is a setting OVS mentioned in a footnote about the allowed output voltage ranges and that it shuts down if OV is hit. It looks like the so called NiCad mode (39.9-66V) must be used for your Li-Ion battery with the required 41V.
Do you adjust this mode or the OVS settings in your application?

In the footnote there is also this hint: "When de-energized module will return to 48V mode."
I don't know if the statement "de-energized" refers to the AC input or DC output. But in case the unit would spit out 48V in special circumstances, are your Li-Ion batteries able to handle this voltage (I don't know which chemical type of Li-Ion batteries are you using)?

Just some ideas...

 

[kta22]

I don't know anything about the Eltek Flatpack2 (I'm using Huawei R4875G1) and I'm not sure if I can really help, but after looking to the spec sheet of the Flatpack2, there is a setting OVS mentioned in a footnote about the allowed output voltage ranges and that it shuts down if OV is hit. It looks like the so called NiCad mode (39.9-66V) must be used for your Li-Ion battery with the required 41V.
Do you adjust this mode or the OVS settings in your application?

In the footnote there is also this hint: "When de-energized module will return to 48V mode."
I don't know if the statement "de-energized" refers to the AC input or DC output. But in case the unit would spit out 48V in special circumstances, are your Li-Ion batteries able to handle this voltage (I don't know which chemical type of Li-Ion batteries are you using)?

Just some ideas...

The unit doesn't start at all, no output voltage or communication ...

 

[fmeili1]

The unit doesn't start at all, no output voltage or communication ...

Try to disconnect the batteries from the DC-output and connect AC-input and disconnect your CAN cable and leave the unit AC-connected of at least an hour. I know that the Huawei R4875G1 automatically doing a reset after some time in case they got "irritated" and made a shutdown (e.g. they shut down if a series of completely wrong CAN command were sent to them and maybe for other reasons). It's worth a try to just wait if they will wake up again.

 

[fmeili1]

Short feedback about the grid idle consumption of the Huawei R4875G1.

Since about 5 weeks, I don't need grid support at all because this time of the year, I have enough solar and very low use of the central heat pump to cover my energy needs easily.

My 4 DIY chargeverters are permanent connected to the grid but "soft" switched OFF (hibernate). My POCO phone app is able to show me my grid consumption per hour/day/week resolution so I can now very accurate measure the idle consumption of the chargeverters (because that is now my only load connected to the grid).

It's 0.26 kWh per 24h and because it's permanent grid connected it also draws power in the on-peak time frame every day.

0.20 kWh off-peak usage (at ¢6.37 / kWh) per day
0.06 kWh on-peak usage (at ¢13.31 / kWh) per day

This results in 6kWh off-peak per month (¢38.22) and 1.8kWh on-peak per month (¢23.96).

Calculating on these value, the idle grid consumption of one of the R4875G1 is about 2.71W in my case my 4 units grid idle consume about 10.8W.

For a bit more than 1/2 a dollar per month it's not worth to add additional contactors to connect/disconnect the R4875 units with the grid and I'll leave them permanently grid connected, even if not used.

 

[fmeili1]

• @fmeili1 wanted to see how things are going with your TOU settings and being able to charge during those times if needed?

I've implemented the rules so far in ESPHome. But because I don't need grid support in this months of the year, I can't really test them in reality. With beginning of June, I'll need grid support again and will be able test if the rules are working.

Some boundary conditions:

• I have a Demand TOU plan with two 3h lasting on-peak time frames in winter (Nov-Apr, 6am-9am and 6pm-9pm) and one 4h lasting on-peak time frame in summer (May-Oct, 3pm-7pm).
• Because it's a "Demand" plan I should try to stay below 7kW grid usage to get the cheapest possible rates

Rules so far:

• I've reduced my "standard" charging amp limit to 32A for all 4 units to stay below the 7kW (if the chargeverters are used, the DC output is usually between 51V and 54V and with 32A amp limit it will stay below the 7kW)
• 2h before an on-peak time frame starts, the rule tries to calculates the (best guess) required SOC to make it over the next on-peak time frame without grid usage by using the following parameters:
  • current battery SOC of my 60kWh battery (provided via MQTT from my smart home system OpenHAB via solar forecast addon - in future I'll try to query the current SOC from modbus directly from the batteries...)
  • estimated required load in kWh to make it over the next on-peak time frame (depending on historical values - hard coded in ESPHome with defined constants per month)
  • estimated PV energy production in kWh for the upcoming next on-peak time frame (provided via MQTT from my smart home system OpenHAB via solar forecast addon - based on location, season, clouds, temperature, etc.). [Also some arithmetic and constants are used in the code because the PV production is a parabola and the area under the parabola is the PV energy and depends on the time frames - it's not linear]
• The main pre-charging rule:
  Based on these values I calculate the SOC which is required before the on-peak time frame starts. In these 2h it charges with 56.5V DC to charge fast and an output current limit setting of 32A (max. 6.9kW) until the required SOC+1 has been reached. After it's reached, the chargeverters are switched off (hibernate). If the required SOC-1 will hit and it's still before the on-peak time frame (still in this 2h pre-charging phase), the chargeverter will pre-charge again until required SOC+1 will hit again.
• In other words, this rule tries 2h before each on-peak time frame to lift the current SOC to the required SOC to make it over the next on-peak time without grid support.
• There is also an emergency grid-usage rule which automatically activate the chargeverters (independent if on-, or off-peak time frame), if SOC falls below 7%. This will set the output limit to 40A (R4875G1 fans are still very quiet at 40A - about 3,000 rpm fan speed) and 51V to try to keep at least the 7%. If the SOC falls below 5% the current limit will be increased to 75A to prevent the batteries from fully depleted.

In the coming months, I need to find out (with try and error) if the 2h pre-charging time frame will be always enough with 32A limit per rectifier to achieve the required SOC. I'm pretty sure that I need to adjust and fine tune these rules later.

 

[mpeterson]

Thank you, @fmeili1, for providing the baseload consumption figures: 2.7W per R4875G1 unit in hibernate. You are right; this is one of the most definitive ways of measuring actual consumption, and hardly anyone will have your setup --- yet. High-current switches and relays are eliminated through that hibernate feature, and you are always ready to import.

In London, once a year, on that cloudless day, it's a parabolic PV curve. We look forward to Parabola Day.

 

[fmeili1]

Thank you, @fmeili1, for providing the baseload consumption figures: 2.7W per R4875G1 unit in hibernate. You are right; this is one of the most definitive ways of measuring actual consumption, and hardly anyone will have your setup --- yet.

It's interesting how accurate these modern energy meters are able to measure even extremely low consumption (11mA with 240V per unit, so in my case about 45mA for all four). The meter is able to measure up to 200A which is about 48kW - I wonder how accurate such a device is able to measure 45mA which is 0.02% of it's max. possible amps.

High-current switches and relays are eliminated through that hibernate feature, and you are always ready to import.

I have the feeling that the whole system is running now even more robust (even though I didn't have any real problems before - but I never liked this switching situation). The lifetime of the appliances will definitively benefit from this online-double-conversion modification. I always worried about the accuracy of the switching time synchronization of the 6 AC-in grid relays.

In London, once a year, on that cloudless day, it's a parabolic PV curve. We look forward to Parabola Day.

I just googled it... 1,350 annual sunshine hours in London - using solar in London seems to be a real challenge and you need to be a real enthusiastic solar guy to use it there
Here we have about 4,000 sunshine hours per year... this makes it a lot easier - but we definitely sweat more

 

[fmeili1]

BOM for 4 units (2 pairs):

 $519.00 - 4x R4875G1 (4 units incl. $135 shipping and incl. $44 for remote loaction DHL addon)
 $ 51.48 - 4x PCB connector for R4875G1
 $ 30.99 - 5x ESP32 ESP-WROOM-32 board
 $  7.99 - 3x CAN bus tranceiver module (SN65HVD230)
 $ 29.96 - 2x 40A double pole Siemens breakers
 $ 59.98 - 2x Nema SS 2-50R 50Amp Receptacle
 $ 39.98 - 2x 50 Amp Twist Lock Plug
 $ 11.99 - 1x DC 12V 24V 48V to 5V Step Down Converter
 $ 12.99 - 1x (pack of two with 200A fuses) MEGA/AMG Fuse Holder 200A
 $  7.49 - 1x 22 AWG JST SM 2 Pin Plug Male and Female Connector (20 pairs)
 $ 33.98 - 2x pair 3/8" (red & black) Heavy Duty Dual Studs Battery Junction Post Terminal Kit
 $ 63.99 - 25ft Welding Cable 8 AWG 40A (I've cut the plugs - only needed the cable)
 $ 20.99 - 1x (pack of two) Battery Disconnect Switch 275A
 $ 12.99 - 1x USB 3.1 Male Connector with Type C Housing set
 $  9.99 - 1x (pack of two) Junction Box
 $ 13.89 - 66ft flexible 22 AWG Electrical Wire (CAN bus)
 $ 11.98 - 10Pcs 6 Awg Splicing Connector (to connect the 8 AWG 240V to 2x 12 AWG inside the junction box)
 $ 88.00 - THHN wire 8 AWG (red, black, white, green each 25ft)
 $ 40.00 - 4 AWG and 6 AWG copper lugs with 3/8 and 5/16 holes
 $ 70.00 - 20 ft 4 AWG and 20 ft 6 AWG battery cable red & black (e.g. WindyNation)
 $ 20.00 - couple of wire terminals 6.3mm for PCB connector and some ring terminals
 $ 40.00 - wood, screws, zip ties, 3D filament, some resistors, LED's, PCB prototyping board, shrink tubing, etc.
======

About $1,200 for 4 units.

Sources:
R4875G1 from ebay (offer for 4 units)
PCB connectors for R4875G1
ESP32 board
CAN bus tranceiver module
40A Siemens double pole breakers
Nema SS 2-50R 50Amp Receptacle
50 Amp Twist Lock Plug
DC 12V 24V 48V to 5V Step Down Converter
MEGA/AMG Fuse Holder 200A
22 AWG JST SM 2 Pin Plug Male and Female Connector
3/8" Heavy Duty Dual Studs Battery Junction Post Terminal Kit
Welding Cable 25ft 8 AWG 40A
Battery Disconnect Switch
USB 3.1 Male Connector with Type C Housing
Junction Box
22 AWG Electrical Wire
6 Awg Splicing Connector
PCB prototype board 5cm x 7cm

Just for completeness, here is the updated BOM after replacing the battery switches and MEGA fuses with 160A MCCB battery breakers and changing to 1/0AWG and 4AWG battery wires and lugs (The change was necessary because the switch terminals, fuses and cables were getting too hot under full load - now all components remain at low/reasonable temperatures.).

After the changes, it's about $100 more expensive than before.

 $519.00 - 4x R4875G1 (4 units incl. $135 shipping and incl. $44 for remote loaction DHL addon)
 $ 51.48 - 4x PCB connector for R4875G1
 $ 30.99 - 5x ESP32 ESP-WROOM-32 board
 $  7.99 - 3x CAN bus tranceiver module (SN65HVD230)
 $ 29.96 - 2x 40A double pole Siemens breakers
 $ 59.98 - 2x Nema SS 2-50R 50Amp Receptacle
 $ 39.98 - 2x 50 Amp Twist Lock Plug
 $ 11.99 - 1x DC 12V 24V 48V to 5V Step Down Converter
 $ 57.00 - 2x 160A, 1 pole battery MCCB breaker
 $  7.49 - 1x 22 AWG JST SM 2 Pin Plug Male and Female Connector (20 pairs)
 $ 33.98 - 2x pair 3/8" (red & black) Heavy Duty Dual Studs Battery Junction Post Terminal Kit
 $ 63.99 - 25ft Welding Cable 8 AWG 40A (I've cut the plugs - only needed the cable)
 $ 12.99 - 1x USB 3.1 Male Connector with Type C Housing set
 $  9.99 - 1x (pack of two) Junction Box
 $ 13.89 - 66ft flexible 22 AWG Electrical Wire (CAN bus)
 $ 11.98 - 10Pcs 6 Awg Splicing Connector (to connect the 8 AWG 240V to 2x 12 AWG inside the junction box)
 $ 88.00 - THHN wire 8 AWG (red, black, white, green each 25ft)
 $ 50.00 - 1/0 AWG and 4 AWG copper lugs with 3/8 and 5/16 holes
 $135.00 - 20 ft 1/0 AWG and 20 ft 4 AWG battery cable red & black (e.g. WindyNation)
 $ 20.00 - couple of wire terminals 6.3mm for PCB connector and some ring terminals
 $ 40.00 - wood, screws, zip ties, 3D filament, some resistors, LED's, PCB prototyping board, shrink tubing, etc.
======

About $1,300 for 4 units.

Sources:
R4875G1 from ebay (offer for 4 units)
PCB connectors for R4875G1
ESP32 board
CAN bus tranceiver module
40A Siemens double pole breakers
Nema SS 2-50R 50Amp Receptacle
50 Amp Twist Lock Plug
DC 12V 24V 48V to 5V Step Down Converter
MEGA/AMG Fuse Holder 200A
160A battery MCCB breaker
22 AWG JST SM 2 Pin Plug Male and Female Connector
3/8" Heavy Duty Dual Studs Battery Junction Post Terminal Kit
Welding Cable 25ft 8 AWG 40A
Battery Disconnect Switch
USB 3.1 Male Connector with Type C Housing
Junction Box
22 AWG Electrical Wire
6 Awg Splicing Connector
PCB prototype board 5cm x 7cm

 

[Robbert]

I'm not sure if the possibility to adjust the volts and amps on the device with LCD display is worth the additional costs. A standard R4875G1 will cost $80 + $49 shipping via eBay from China (total: $129) which is still $100 less compared to $143.30 + $85.73 shipping (total: $229.03). The model from the 2nd link even more expensive.

If you just want to use these units as a LiFePO4 charger I would go for the standard R4875G1 with the additional CAN overhead to implement to program them. In case you would add a 2nd unit, the CAN controller could be the same to control more than one unit which makes it even cheaper.

Usually you set (program) a fix output voltage once (e.g. 51V) which will keep the SOC for a LFP battery at about 20% and protect your battery from undervoltage situations with the help from grid or generator.
You even don't need to program. It's possible to buy a USB-CAN-Bus adapter, plug it into a PC, download a free CAN-Bus tool (e.g. SavvyCAN) and program the output voltage (and amps limit) and the fallback volts and amps and you are good to go. After programming the values, you can unplug the CAN communication and the unit will persist your changes.

In case you are looking for an "adjustable laboratory power supply" in a voltage range from 50-103 (or 48-58.8V for the other model) because of other use cases for a power supply, it may be useful.

Maybe a stupid question, but you write that you can simply use one on e.g 51 volts to prevent battery from draining.

Does that mean you can attach it to the busbar and just leave it on?

So it's my understanding that it will stop charging when a programmed voltage is reached. Isn't it a problem, leaving it on and attached when my SCCs start pumping 55.7v in the system?

 

[fmeili1]

Maybe a stupid question, but you write that you can simply use one on e.g 51 volts to prevent battery from draining.

there are no stupid questions... only stupid answers

Does that mean you can attach it to the busbar and just leave it on?

Yes, you connect the output permanent to the bus bars, set it to a specific voltage which you don't want to fall below and the chargeverter will keep this voltage by increasing or decreasing the amps (depending on current battery SOC and current load which draws amps from the bus bars to the inverters).

So it's my understanding that it will stop charging when a programmed voltage is reached. Isn't it a problem, leaving it on and attached when my SCCs start pumping 55.7v in the system?

yes, exactly! Your chargeverter current will drop to zero (and stays at zero) when the bus voltage rises above the programmed output voltage of the chargeverter. It's not digital like start/stop charging, it's analog and the amps draws from the chargeverter depending on the current voltage of the DC bus.

Here are some charts from one of my tests from January where I set the DC output to 51V and let it run:

SOC chart before the night begins, starting at 33% and was not falling below 7% at the end of the night before new solar production begins.


Battery voltage chart in the same time range:


Battery amps chart:


Chargeverter power consumption in the same time range (4 chargeverters set to 40A limit each which is 8,000W limit total):

You can clearly see that the power which the chargeverters needs to add is increasing over night to be able to keep the 51V on the DC bus. The spikes in the voltage and power charts showing the times when our 5 ton central heat pump was running. This high load lets the battery voltage dropping a bit more and the chargeverter tries to balance this out by providing more current (power) to the bus.

Btw. The nice thing is, this is done "automatically" and no "active controlling" is required to achieve this [these are fundamental electrical laws like Kirchhoff's law (the sum of currents entering a junction equals the sum of currents leaving it, and the sum of voltage drops around a closed loop equals zero) and Ohm's law which describes the relationship between voltage, current and resistance].

 

[Robbert]

there are no stupid questions... only stupid answers

Yes, you connect the output permanent to the bus bars, set it to a specific voltage which you don't want to fall below and the chargeverter will keep this voltage by increasing or decreasing the amps (depending on current battery SOC and current load which draws amps from the bus bars to the inverters).

yes, exactly! Your chargeverter current will drop to zero (and stays at zero) when the bus voltage rises above the programmed output voltage of the chargeverter. It's not digital like start/stop charging, it's analog and the amps draws from the chargeverter depending on the current voltage of the DC bus.

Here are some charts from one of my tests from January where I set the DC output to 51V and let it run:

SOC chart before the night begins, starting at 33% and was not falling below 7% at the end of the night before new solar production begins.
View attachment 287990

Battery voltage chart in the same time range:
View attachment 287998


Chargeverter power consumption in the same time range (4 chargeverters set to 40A limit each which is 8,000W limit):
View attachment 287994
You can clearly see that the power which the chargeverters needs to add is increasing over night to be able to keep the 51V on the DC bus. The spikes in the voltage and power charts showing the times when our 5 ton central heat pump was running. This high load lets the battery voltage dropping a bit more and the chargeverter tries to balance this out by providing more current (power) to the bus.

Btw. The nice thing is, this is done "automatically" and no "active controlling" is required to achieve this [these are fundamental electrical laws like Kirchhoff's law (the sum of currents entering a junction equals the sum of currents leaving it, and the sum of voltage drops around a closed loop equals zero) and Ohm's law which describes the relationship between voltage, current and resistance].

Wow, that's fast and comprehensive! Thank you very much
One final question though.

In an other post you write about the hybernation and the power consumption during hybernation.
Is hybernation programmed, is or is that at the moment the charger simply doesn't do anything (because the SCCs are pumping in engergy)?

This is the final one, before I click the 'order button'

 

[fmeili1]

Wow, that's fast and comprehensive! Thank you very much
One final question though.

In an other post you write about the hybernation and the power consumption during hybernation.
Is hybernation programmed, is or is that at the moment the charger simply doesn't do anything (because the SCCs are pumping in engergy)?

The hibernate mode could only be activated/deactivated by specific CAN Bus commands. The units does not automatically going to hibernate!
But you need CAN Bus controlling anyway to be able to use the full features (beside DC voltage and DC amp limit settings) of the units like hibernate, fan speed control, OV protection, AC input amp limit possibility, etc.).
If you're using a "raw" unit R4875G1 a CAN Bus controlling is a must. If you're using one of these "modified units" on Ali with integrated knobs/display just for the settings of volt and amps your are limited to just using these two parameters.
It's also possible to set the fallback voltages/amp limit beside the actual values. The fallback values are used after the units are rebooting and stored persistent inside the units after programmed. But I highly recommend to use a permanent CAN Bus controller with the units and they are very cheap and there are some DIY projects with ESP32 / ESPHome on github which implemented this controlling. I've used the CAN-BUS-control-R4875G1-with-ESPHome-and-MQTT project as a blueprint to control my 4 units.

This is the final one, before I click the 'order button'

 

[Robbert]

Read the project on GitHub and ordered one. Not experienced with development boards so it will become interesting

 

[fmeili1]

Read the project on GitHub and ordered one. Not experienced with development boards so it will become interesting

I'm sure you'll like it!
I'll take a bit of time to get convenient if you're new to this ESP32/ESPHome environment - but it's worth the effort and will open many possibilities which you're not seeing right now - and it's fun

 

[Robbert]

I'm sure you'll like it!
I'll take a bit of time to get convenient if you're new to this ESP32/ESPHome environment - but it's worth the effort and will open many possibilities which you're not seeing right now - and it's fun

Just received my WROOM boards and CAN adapters from Amazon. Setting it up seems pretty straightforward (very good instructions on the github page) and I have one board in HA.
The recitifiers are still on their way, and I expect them to arrive in about two weeks.

Now looking at the settings and sensors. All make sense, but I am puzzeled about the fallback limit options.
I think with the voltage limit and DC charge limit, I just can set the right voltage and amperage to the charger. Is this correct?

So what are the fallback voltage and DC current limits for?


E.g. if I want to set the charge to charge with 55.6V and 35amps, do I need to set those values in all fields (the voltage limit and the fallback limit)?

 

[fmeili1]

Just received my WROOM boards and CAN adapters from Amazon. Setting it up seems pretty straightforward (very good instructions on the github page) and I have one board in HA.
The recitifiers are still on their way, and I expect them to arrive in about two weeks.

Now looking at the settings and sensors. All make sense, but I am puzzeled about the fallback limit options.
I think with the voltage limit and DC charge limit, I just can set the right voltage and amperage to the charger. Is this correct?

So what are the fallback voltage and DC current limits for?


E.g. if I want to set the charge to charge with 55.6V and 35amps, do I need to set those values in all fields (the voltage limit and the fallback limit)?



View attachment 290649

The fallback settings (DC output voltage and DC output current limit) are used if the units are loosing CAN bus communication and when units are restarted (without CAN bus) - these are like the default settings after reboot! I guess, if you never change these fallback settings, they will be at a factory preset level (e.g. maybe 48V and 20A).
In my case I set the fallback voltage ONCE to 51 (to keep the batteries at least at 7% SOC) and at 40A current limit (to keep the fan noise at a comfortable level). For my daily usage I only use the standard voltage and current limit values in my smart home rules to control the grid usage.

 

[wwu123]

Your video looks promising, as a suggestion, you might want to check if you can charge these packs through an expansion port... That avoids the losses from the MPPT and potential fighting of the MPPT with the amp control of the R4875G...

Apologies I know this is slightly off-topic for the thread, but I just found it curiously timed - you were suggesting a few weeks ago to instead use the chargerectifiers to charge my Anker F3800 through the battery expansion port, which uses a proprietary cable. Just a week or so ago, someone did figure out that the large pins on the prorprietary cable are just the raw 51.2V pins straight to the internal battery cells. So now a few folks working on experimenting with DIY adapters to external batteries in parallel directly, but could also be used to connect the chargerectifiers directly (and thus bypass the 1150W limit of the DC solar parts along with bypassing the MPPT) - either by 3D printing the connector plug or cutting off one end of a factory cable.

Early experiments show the only downside is the SoC reporting of the power station gets completely borked, as it is not able to monitor the power inflows and outflows. I presume with the official expansion batteries, some of the smaller pins are for closed-loop comms between the expansion and the main unit battery, so it can keep track of power in/out and estimate SoC. But all that is lost when sending power in/out with a hacked connector with no communications...

 

[Robbert]

The fallback settings (DC output voltage and DC output current limit) are used if the units are loosing CAN bus communication and when units are restarted (without CAN bus) - these are like the default settings after reboot! I guess, if you never change these fallback settings, they will be at a factory preset level (e.g. maybe 48V and 20A).
In my case I set the fallback voltage ONCE to 51 (to keep the batteries at least at 7% SOC) and at 40A current limit (to keep the fan noise at a comfortable level). For my daily usage I only use the standard voltage and current limit values in my smart home rules to control the grid usage.

Finally received the first charger. The other one is still on its way.
Hooked it up to the ESP-board and it works flawlessly. So happy that I followed this thread.

 

[Robbert]

The chargenectifier was connected to my system and peformed great. The only downside is the weak wifi, so I bought a new wifi access point that is now in my basement. Would love to have a board that has ethernet and works with the software. I will reach out to the developper to see what he recommends.

In the mean while I ordered an enclosure, so I can install the chargenectifier permanently in my system. The work is almost done, but since I live on an island, I need to order some suitable cable lugs and cable glands to finalize it. For now I use a 6mm wire and that is enough for 30 amps.

I also will buy a resistor and push button for the pre-charge and install that later.

 

[fmeili1]

The chargenectifier was connected to my system and peformed great. The only downside is the weak wifi, so I bought a new wifi access point that is now in my basement. Would love to have a board that has ethernet and works with the software. I will reach out to the developper to see what he recommends.

Looks awesome! Nice work

Do you use an ESP8266 or an ESP32 board (I can't identify it in your pictures). The ESP32 Wi-Fi is much better compared to the ESP8266. You also may consider to attach an external Wi-Fi antenna which may help a lot (see this example).
There are also ESP32 with integrated ethernet available (see this example - but I never used one of these).

 

[Robbert]

Looks awesome! Nice work

Do you use an ESP8266 or an ESP32 board (I can't identify it in your pictures). The ESP32 Wi-Fi is much better compared to the ESP8266. You also may consider to attach an external Wi-Fi antenna which may help a lot (see this example).
There are also ESP32 with integrated ethernet available (see this example - but I never used one of these).

I use the ESP32 Vroom board.
Will order a LAN enabled board and test it.

 

[mpeterson]

Nice build, you don't really need a precharge resistor.

to connect the R4875 to a battery:

1) set the charger to something like 1A,
2) Set voltage to match battery voltage,
3) switch on the R4875G and then
4) connect the battery to the R4875


If you want to connect the battery and the R4875 to your inverter, use the following procedure

1) switch off the R4875, switch off inverter
2) connect the R4875 to the inverter
3) set R4875 to battery voltage and 1A
4) Switch on R4875
5) connect the battery to the inverter


no sparks

 

[Dave911]

The chargenectifier was connected to my system and peformed great. The only downside is the weak wifi, so I bought a new wifi access point that is now in my basement. Would love to have a board that has ethernet and works with the software. I will reach out to the developper to see what he recommends.

In the mean while I ordered an enclosure, so I can install the chargenectifier permanently in my system. The work is almost done, but since I live on an island, I need to order some suitable cable lugs and cable glands to finalize it. For now I use a 6mm wire and that is enough for 30 amps.

I also will buy a resistor and push button for the pre-charge and install that later.

Is that an official chargenectifier case?
Where did you find that?

 

[Robbert]

Is that an official chargenectifier case?
Where did you find that?

I bought it at TME.eu.
Actually it's a 19 inch 2U rack mount.

It is made of plastic instead of metal. That is the reason why I added aluminium supports. The rectifier can get pretty warm so with the supports it doesn't touch the plastic.

Also I added something around the rectifier in the front to force it to suck in fresh air and prevent hot air to circle around.