DIY 'Chargenectifier'

[silverstone]

Yeah it's the same no matter the voltage

Temp (C) : 14.197265625
Vin (VAC) : 220.5390625
Vout (VDC) : 58.43359375
Iout (IDC) : 0.0
Output Current Limit : 0.96875

 

[upnorthandpersonal]

I don't remember what it does when you put a load on it and play with setting the limit, and I can't test it right now. I vaguely remember that it changes... Could be completely wrong.

 

[silverstone]

I don't remember what it does when you put a load on it and play with setting the limit, and I can't test it right now. I vaguely remember that it changes... Could be completely wrong.

No fair enough . I will probably get the chance to see it during normal operation.

For now my goal was just to have something to play with to debug the main aspects of the class. Basically set/get from the user and set/get internal to the class and their associated loops to make sure that the settings are set say every 15 seconds and the values read every 1 second or so.

But at least the external user doesn't have to deal with the loops.

And of course I don't want to bring down my main system just to debug the basic bugs in my class .

 

[silverstone]

@webbbn I just pushed a change trying to get these asyncio things working. Just pushed to the git repo -> https://github.com/luckylinux/R48_Rectifier/

There is surely something I'm missing out with.

I am getting lots of CAN / socketcan errors, not sure what's going on. The sleeping / waiting time seems correct between each error (approx. 1 second), but it's like two tasks are running at the same time or getting canceled midway ?

Command sent on socketcan channel 'can-grid-00'
Exception in thread can.notifier for bus "socketcan channel 'can-grid-00'":
Traceback (most recent call last):
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 531, in capture_message
    cf, ancillary_data, msg_flags, addr = sock.recvmsg(
                                          ^^^^^^^^^^^^^
OSError: [Errno 9] Bad file descriptor

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.11/threading.py", line 1045, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.11/threading.py", line 982, in run
    self._target(*self._args, **self._kwargs)
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/notifier.py", line 124, in _rx_thread
    if msg := bus.recv(self.timeout):
              ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/bus.py", line 121, in recv
    msg, already_filtered = self._recv_internal(timeout=time_left)
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 744, in _recv_internal
    msg = capture_message(self.socket, get_channel)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 539, in capture_message
    raise can.CanOperationError(f"Error receiving: {error.strerror}", error.errno)
can.exceptions.CanOperationError: Error receiving: Bad file descriptor [Error Code 9]
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Exception in thread can.notifier for bus "socketcan channel 'can-grid-00'":
Traceback (most recent call last):
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 531, in capture_message
    cf, ancillary_data, msg_flags, addr = sock.recvmsg(
                                          ^^^^^^^^^^^^^
OSError: [Errno 9] Bad file descriptor

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.11/threading.py", line 1045, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.11/threading.py", line 982, in run
    self._target(*self._args, **self._kwargs)
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/notifier.py", line 124, in _rx_thread
    if msg := bus.recv(self.timeout):
              ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/bus.py", line 121, in recv
    msg, already_filtered = self._recv_internal(timeout=time_left)
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 744, in _recv_internal
    msg = capture_message(self.socket, get_channel)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 539, in capture_message
    raise can.CanOperationError(f"Error receiving: {error.strerror}", error.errno)
can.exceptions.CanOperationError: Error receiving: Bad file descriptor [Error Code 9]
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Exception in thread can.notifier for bus "socketcan channel 'can-grid-00'":
Traceback (most recent call last):
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 531, in capture_message
    cf, ancillary_data, msg_flags, addr = sock.recvmsg(
                                          ^^^^^^^^^^^^^
OSError: [Errno 9] Bad file descriptor

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.11/threading.py", line 1045, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.11/threading.py", line 982, in run
    self._target(*self._args, **self._kwargs)
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/notifier.py", line 124, in _rx_thread
    if msg := bus.recv(self.timeout):
              ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/bus.py", line 121, in recv
    msg, already_filtered = self._recv_internal(timeout=time_left)
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 744, in _recv_internal
    msg = capture_message(self.socket, get_channel)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/venv/lib/python3.11/site-packages/can/interfaces/socketcan/socketcan.py", line 539, in capture_message
    raise can.CanOperationError(f"Error receiving: {error.strerror}", error.errno)
can.exceptions.CanOperationError: Error receiving: Bad file descriptor [Error Code 9]
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
Command sent on socketcan channel 'can-grid-00'
^C_GatheringFuture exception was never retrieved
future: <_GatheringFuture finished exception=CancelledError()>
Traceback (most recent call last):
  File "/usr/lib/python3.11/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/asyncio/base_events.py", line 653, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/rectifier.py", line 173, in __loop
    await asyncio.shield(asyncio.gather(self.__can_send_loop() , self.__can_receive_loop()))
asyncio.exceptions.CancelledError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.11/asyncio/runners.py", line 190, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/asyncio/runners.py", line 123, in run
    raise KeyboardInterrupt()
KeyboardInterrupt

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/user/Repositories/R48_Rectifier/rectifier.py", line 222, in __can_send_loop
    await asyncio.sleep(self.INTERVAL_SEND_DATA)
  File "/usr/lib/python3.11/asyncio/tasks.py", line 649, in sleep
    return await future
           ^^^^^^^^^^^^
asyncio.exceptions.CancelledError
Traceback (most recent call last):
  File "/usr/lib/python3.11/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/asyncio/base_events.py", line 653, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "/home/user/Repositories/R48_Rectifier/rectifier.py", line 173, in __loop
    await asyncio.shield(asyncio.gather(self.__can_send_loop() , self.__can_receive_loop()))
asyncio.exceptions.CancelledError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/user/Repositories/R48_Rectifier/app.py", line 15, in <module>
    Charger.run(debug=True)
  File "/home/user/Repositories/R48_Rectifier/rectifier.py", line 146, in run
    asyncio.run(self.__loop())
  File "/usr/lib/python3.11/asyncio/runners.py", line 190, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/asyncio/runners.py", line 123, in run
    raise KeyboardInterrupt()
KeyboardInterrupt

Is there something obvious in my await, async, asyncio.sleep / asyncio.gather ? I used asyncio.shield as there were lots of error messages about tasks getting canceled.

 

[jamiegreen]

Just a little update, upgraded my generator to a 3 cyl Kubota 7kw unit salvaged from an ex army lighting tower. Gave it a good cleanup and service and build an autostart control panel for it. Figured I might aswell make use of the increased power output and get a second AC charger from the AliExpress seller. Just waiting on a timer relay to delay the second charger kicking in, as not to dump a 6.5kw load on the generator at once (programmed after a 15 second "warm up" time), I'll let the first charger start up and delay the second one by another 5 minutes or so. But today's test run had good results, chargers work great, seem to be around 85-90% efficient. I do want to downrate the fuses, although the cable is capable of handling 100a, and it's just what I had on hand at the time, a 70-80a would be more suitable per charger.

 

[42OhmsPA]

Just a little update, upgraded my generator to a 3 cyl Kubota 7kw unit salvaged from an ex army lighting tower. Gave it a good cleanup and service and build an autostart control panel for it. Figured I might aswell make use of the increased power output and get a second AC charger from the AliExpress seller. Just waiting on a timer relay to delay the second charger kicking in, as not to dump a 6.5kw load on the generator at once (programmed after a 15 second "warm up" time), I'll let the first charger start up and delay the second one by another 5 minutes or so. But today's test run had good results, chargers work great, seem to be around 85-90% efficient. I do want to downrate the fuses, although the cable is capable of handling 100a, and it's just what I had on hand at the time, a 70-80a would be more suitable per charger.

That's awesome.

 

[silverstone]

I'm considering doing a backplane, because it seems the most compact solution.

I got 12 of these Emerson/Vertiv R48-3000e3 right now and only 2 are cabled.

Because doing a wooden shelf is going to take A LOT of space (basically it would be taller than the charger itself ...) which I don't really have.



Any idea on how to approach this ?

Or any better alternative ?

Or maybe the crazy approach of just laying them on the short side on top of a shelf, maybe with the power connectors on the front side, in case I need to re-tighten or something ?

 

[jamiegreen]

I'm considering doing a backplane, because it seems the most compact solution.

I got 12 of these Emerson/Vertiv R48-3000e3 right now and only 2 are cabled.

Because doing a wooden shelf is going to take A LOT of space (basically it would be taller than the charger itself ...) which I don't really have.

View attachment 204715

Any idea on how to approach this ?

Or any better alternative ?

Or maybe the crazy approach of just laying them on the short side on top of a shelf, maybe with the power connectors on the front side, in case I need to re-tighten or something ?

How much battery capacity do you have to be able to charge at 36kw! And what supplies that on the AC side, grid?
I like the look of that rack, looks like it might also leave a small gap between the chargers, possibly a good idea if your running multiples for heat dissipation. I think some form of securement would be a good idea with that many, that's a lot of power to just.. sit around.

 

[silverstone]

How much battery capacity do you have to be able to charge at 36kw! And what supplies that on the AC side, grid?
I like the look of that rack, looks like it might also leave a small gap between the chargers, possibly a good idea if your running multiples for heat dissipation. I think some form of securement would be a good idea with that many, that's a lot of power to just.. sit around.

At the moment it's only 30 kWh. Soon it will be 60kWh. Planned to hit 120 kWh overall. If I stop there .

Grid is 35A so 3 x 230V x 35A = 24kW. But it's also best NOT to use these chargers at 100% all the time ... Both for wear, redundancy, maintenance, etc.

I'm not that keen on designing a whole PCB for it though. And the provided PCB Interfaces cannot be easily mounted (unless they are just "plugged in by hand", but not attached to anything, there is no mounting hole etc).

 

[silverstone]

The other alternative is just to lay the different units on the short edge on the shelf and separate each with a Polycarbonate plate, in order to avoid short-circuit if I have to do maintenance etc.

Designing a PCB backplane is not something I currently have the time for

 

[silverstone]

@upnorthandpersonal Do you know the type / model of the connector on the back of the Vertiv/Emerson R48-3000e3 ?



Maybe I'll do a very simple backplane after all, if the connectors are something that can be bought on Mouser / Digikey / etc ...

One weird thing I observed is that, even when NOT delivery any power to the DC bus, if the DC bus / Battery voltage rises, then the fans go much louder. Granted there is a BIT of extra power on the discharge resistors in the output capacitor filter, but it shouldn't be that massive, going from 52V to 56V (both at 0A).


EDIT 1: it seems like the very old ISA slots on old Motherboards


EDIT 2: 26 pins total / 19 pins installed

EDIT 3: Maybe this ? But it does NOT have the notch between the + and - connector but it's either 50 pins (25) or 56 pins (28).

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EDIT 4: Or rather this ? The notch seems to be too much towards the middle though (it's placed at 33% here, in reality it looks much less like 25%):

https://www.mouser.dk/ProductDetail/Samtec/HSEC8-125-01-S-DV-A?qs=Cqqh%252BS766wnTbCfCnG68Ig%3D%3D

 

[silverstone]

One weird thing I observed is that, even when NOT delivery any power to the DC bus, if the DC bus / Battery voltage rises, then the fans go much louder. Granted there is a BIT of extra power on the discharge resistors in the output capacitor filter, but it shouldn't be that massive, going from 52V to 56V (both at 0A).

@upnorthandpersonal: Are you also observing that ? Zero load, battery voltage higher-ish possibly also due to charging from the inverters (a few extra volts from 51-52 VDC "floor"), fans spin up quite a bit ?

My (temporary) cabling is as follows:

Each Battery <-----> 10 m cable 2x16mm2 each polarity <---> WAGO 285-150 Terminal Blocks paralleled together with jumpers <--> 10 m cable 1x16mm2 each polarity <--> Each Charger

and

Each Battery <-----> 10 m cable 2x16mm2 each polarity <---> WAGO 285-150 Terminal Blocks paralleled together with jumpers <--> 10 m cable 2x16mm2 each polarity <--> Each Inverter

10m of 1x16mm2 is approx. 10 mOhm.

So effectively the Inverter Voltage is quite a bit higher than the battery (I could see during testing 55.7V - 56V when battery was like 54V or so).

At 50A to make it easier ... each cable is approx 50A x 0.01 Ohm = 0.5 V


So:
Inverter Voltage (e.g. 55.5 VDC) <--> WAGO 285-150 (55.0 VDC) <--> Charger at no load (55.0 VDC)

Inverter Voltage (e.g. 55.5 VDC) <--> WAGO 285-150 (55.0 VDC) <--> Battery (54.5 VDC)


Do you observe the same just because of the output voltage increase ? Basically fans spinning up like crazy even at zero output current, as soon as the output voltage gets higher ?

I mean ... we are talking about 1.0-2.0 VDC, that's like in the worst case (56V/52V)^2 = 16 % extra power dissipation on the output filter resistor ... It's NOT that much.

 

[upnorthandpersonal]

@upnorthandpersonal: Are you also observing that ? Zero load, battery voltage higher-ish possibly also due to charging from the inverters (a few extra volts from 51-52 VDC "floor"), fans spin up quite a bit ?

I'll try to check. Mine tend to be only running when in use (AC is only there when actually charging from the generator).

 

[silverstone]

I'll try to check. Mine tend to be only running when in use (AC is only there when actually charging from the generator).

Yeah otherwise I think I'd really install a contactor maybe in combination with SSR (delayed contactor turn-on, delayed SSR turn off) to reduce as much as possible transients & power losses.

For the Fan lifetime for sure this isn't great. Let alone that you cannot hear anything in the garage once these chargers start going ...

 

[42OhmsPA]

Over a year later finally got around to ordering one of the Emersons.
$89.51 with shipping and tax.
Should be here in a couple weeks.

Went with the 57V pre-programmed.
Plan to use it for a 'quick charge' of 690Ah of cells I'm picking up Sunday before top balancing. Now to find the best price on more JBDs.

Here's the link I used, the one I had in my cart said no longer available, I panicked for a second, but the seller must have made a new listing.

I noticed a familiar looking photo in one of the reviews. .

Just found this amazing item on AliExpress. Check it out!
$49.82 | Emerson R48-3000e3 Communication Switching Power Supply Module 48V Induction Heater Power Supply Disassemble With interface

https://a.aliexpress.com/_mr73c18

I'll regret not ordering 2 of the them about 30 minutes in to charging

 

[silverstone]

Over a year later finally got around to ordering one of the Emersons.
$89.51 with shipping and tax.
Should be here in a couple weeks.

Went with the 57V pre-programmed.
Plan to use it for a 'quick charge' of 690Ah of cells I'm picking up Sunday before top balancing. Now to find the best price on more JBDs.

Here's the link I used, the one I had in my cart said no longer available, I panicked for a second, but the seller must have made a new listing.

I noticed a familiar looking photo in one of the reviews. .

Just found this amazing item on AliExpress. Check it out!
$49.82 | Emerson R48-3000e3 Communication Switching Power Supply Module 48V Induction Heater Power Supply Disassemble With interface

https://a.aliexpress.com/_mr73c18

I'll regret not ordering 2 of the them about 30 minutes in to charging

That seems quite expensive. Don't you have something in the US like in the EU, that Aliexpress automatically adds VAT on it, so you don't get customs surprises ?

I also ordered at that seller, but I buy in packs of 3 for that reason. Shipping is almost constant, yet VAT is pre-paid (up to 150 EUR I believe), so if you exceed 150 EUR you'll get an extra 25 EUR surcharge from customs. Buy in pack of 3 and it's alright (of course, always check that) .

Buying in Packs of 3 (with Cainao Shipping option - least expensive) for 200 EUR you get 3 chargers shipped including VAT and no extra surprises

 

[silverstone]

Back to my idea of a Rack, since PCB design and mechanical integration would take some time, I am considering some fasttrack methods ...

A rack built using Polycarbonate plates cut to size.




- Red is Polycarbonate Plates (6mm thick vertical, 3mm thick horizontal)
- Blue is the Charger
- Black/Grey is an Aluminium U-Profile outside 8mm x 8mm and inside 6mm slot/space (1mm thick only ... maybe I also need to buy the bigger brother and put one inside the other, so I would get 2mm thick total)

So on a width 440 mm x height 300mm x depth 400mm I could fit 24 chargers .

And connection wise, I could use the PCB that they delivered together with the charger, with connections accessible from the front, in case of needing to replace a charger, retorque connections, etc.

Some spacers towards the wall (to give fan some air to breathe, maybe 20mm or 30mm thick spacers).

Why polycarbonate so "deep" (400mm polycarbonate vertical slots, when charger is only 330mm) ? Well, I don't want short-circuits during maintenance, when I'm pulling one charger out and maybe the PCB hits the charger nearby .

But that's still around 140 EUR just for the Polycarbonate.

The U-Profiles I found quite cheap on Amazon or other Websites in Germany (approx. 2-4 EUR / 1 m). Not that I'm very found of aluminum near the charger, which seems somewhat steel case (NOT very magnetic though, but definitively somewhat - ideas ?).

Other ideas ?

It has to be compact. Losing 50-100 mm for each wooden shelf/bracket is NOT an option.

 

[42OhmsPA]

That seems quite expensive. Don't you have something in the US like in the EU, that Aliexpress automatically adds VAT on it, so you don't get customs surprises ?

I also ordered at that seller, but I buy in packs of 3 for that reason. Shipping is almost constant, yet VAT is pre-paid (up to 150 EUR I believe), so if you exceed 150 EUR you'll get an extra 25 EUR surcharge from customs. Buy in pack of 3 and it's alright (of course, always check that) .

Buying in Packs of 3 (with Cainao Shipping option - least expensive) for 200 EUR you get 3 chargers shipped including VAT and no extra surprises
View attachment 206445

I'll look into buying bulk quantities next time, I know I will use them. That cost should be all fees included.
You're getting them each ~$20 cheaper when you buy 3.

Back to my idea of a Rack, since PCB design and mechanical integration would take some time, I am considering some fasttrack methods ...

A rack built using Polycarbonate plates cut to size.

View attachment 206447


- Red is Polycarbonate Plates (6mm thick vertical, 3mm thick horizontal)
- Blue is the Charger
- Black/Grey is an Aluminium U-Profile outside 8mm x 8mm and inside 6mm slot/space (1mm thick only ... maybe I also need to buy the bigger brother and put one inside the other, so I would get 2mm thick total)

So on a width 440 mm x height 300mm x depth 400mm I could fit 24 chargers .

And connection wise, I could use the PCB that they delivered together with the charger, with connections accessible from the front, in case of needing to replace a charger, retorque connections, etc.

Some spacers towards the wall (to give fan some air to breathe, maybe 20mm or 30mm thick spacers).

Why polycarbonate so "deep" (400mm polycarbonate vertical slots, when charger is only 330mm) ? Well, I don't want short-circuits during maintenance, when I'm pulling one charger out and maybe the PCB hits the charger nearby .

But that's still around 140 EUR just for the Polycarbonate.

The U-Profiles I found quite cheap on Amazon or other Websites in Germany (approx. 2-4 EUR / 1 m). Not that I'm very found of aluminum near the charger, which seems somewhat steel case (NOT very magnetic though, but definitively somewhat - ideas ?).

Other ideas ?

It has to be compact. Losing 50-100 mm for each wooden shelf/bracket is NOT an option.

I think using the extrusions makes the most sense.
If you have a local fab shop around you could see what they would quote to make something.
Only other thought would be using sheet metal, angle iron and rivets to make a holder.

 

[silverstone]

I'll look into buying bulk quantities next time, I know I will use them. That cost should be all fees included.
You're getting them each ~$20 cheaper when you buy 3.



I think using the extrusions makes the most sense.
If you have a local fab shop around you could see what they would quote to make something.
Only other thought would be using sheet metal, angle iron and rivets to make a holder.

Metal is electrically conductive. I don't want to lose a PCB and causing a huge short-circuit when I'm doing maintenance .

About extrusions not sure ...Everything here in Denmark is extremely expensive. Surprisingly not so much cut-to-pieces polycarbonate or acrylic plates though (Germany is more expensive). Maybe I could try to find something in Poland or East Europe, that should be cheaper I guess.

Extrusions ... of Metal (Aluminium I guess) or Plastic (do they make Polycarbonate extrusions ?) ??? I guess Plastic wise it has to be somewhat high temperature resistance (e.g. PLA 3D printing would NOT work for instance, ABS might though at ~ 85°C service temperature or so).

EDIT 1: although I guess that something like Polyamide / Nylon with Glass Fiber reinforcement would be quite nice if it were to get extruded.

EDIT 2: somehow I'm skeptical that for a "1 piece prototype" order it will cost less than 150 EUR. If anybody has any contacts in Europe that does that prototype service feel free to suggest though .

 

[Gubman]

@upnorthandpersonal Do you know the type / model of the connector on the back of the Vertiv/Emerson R48-3000e3 ?

View attachment 205166

Maybe I'll do a very simple backplane after all, if the connectors are something that can be bought on Mouser / Digikey / etc ...

One weird thing I observed is that, even when NOT delivery any power to the DC bus, if the DC bus / Battery voltage rises, then the fans go much louder. Granted there is a BIT of extra power on the discharge resistors in the output capacitor filter, but it shouldn't be that massive, going from 52V to 56V (both at 0A).


EDIT 1: it seems like the very old ISA slots on old Motherboards
View attachment 205173

EDIT 2: 26 pins total / 19 pins installed

EDIT 3: Maybe this ? But it does NOT have the notch between the + and - connector but it's either 50 pins (25) or 56 pins (28).

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www.te.com

5530843-6 : Card Edge Power Connectors

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EDIT 4: Or rather this ? The notch seems to be too much towards the middle though (it's placed at 33% here, in reality it looks much less like 25%):

https://www.mouser.dk/ProductDetail/Samtec/HSEC8-125-01-S-DV-A?qs=Cqqh%252BS766wnTbCfCnG68Ig%3D%3D

They look like ISA slots not so much because of any relation to "ISA bus/protocols" but its because of a tried-and-tested physical connector standard for its time. Beefy contacts and a road tested ability are also a benefit. Notice how tiny the contact pints are on the PCI or PCI-E relative to "old school". This connector approach is also beneficial when you need to vary pin the contact count without the need to change the plastic injection moulding chucks or forms.