DIY 'Chargenectifier'

[42OhmsPA]

16AWG is less than 1.5mm2, I wouldn't put 10A on it, let alone 40A.

6mm2 for 40A is a gamble (depending if PVC/XLPE Insulation and Installation Conditions among other Things), I would just take 10mm2 or, since I never use that size, standardize to 16mm2 since that's the next size I commonly use.

So probably AWG8 or AWG7 ...

I was using 16AWG on the AC, ~20A
I knew it was a bad idea when I grabbed it out of the pile, it was the only thing I could find that had an end on it.... It's been replaced (temporarily ) with 12AWG silicone insulation and a new cord end.
The 10AWG on the DC side is marine rated.

When I get everything wired up permanently I'm going to use 10AWG on the AC side and 6AWG or 8AWG on the DC side.

I'll be using it primarily with the 120V inverter generator in the winter but could also use the big noisy 240V generator.

Thank you for taking the time to reply.

 

[silverstone]

I was using 16AWG on the AC, ~20A
I knew it was a bad idea when I grabbed it out of the pile, it was the only thing I could find that had an end on it.... It's been replaced (temporarily ) with 12AWG silicone insulation and a new cord end.
The 10AWG on the DC side is marine rated.

When I get everything wired up permanently I'm going to use 10AWG on the AC side and 6AWG or 8AWG on the DC side.

I'll be using it primarily with the 120V inverter generator in the winter but could also use the big noisy 240V generator.

Thank you for taking the time to reply.

The 3000W version r48-3000e3 should be able to do 50A actually.

Did you get another Version ? Or you limited via Software to 40A DC output (or Input Current/Power Limited) ?

 

[42OhmsPA]

The 3000W version r48-3000e3 should be able to do 50A actually.

Did you get another Version ? Or you limited via Software to 40A DC output (or Input Current/Power Limited) ?

I'm input power limited currently, I didn't expect 40A with 120VAC, I was quite happy and figured I'd only see around 25A.

Thanks for verifying, I was figuring I'd see around 50A with 240VAC.

 

[silverstone]

I'm input power limited currently, I didn't expect 40A with 120VAC, I was quite happy and figured I'd only see around 25A.

Thanks for verifying, I was figuring I'd see around 50A with 240VAC.

With the wires you have in your circuit, it might simply be a case of Ohm's Law .

If your current is BELOW 50A, then the Charger is in Voltage Control mode. That's the case near the Top of the Charge Curve OR if your Wire/Connection Resistance is quite high. Otherwise, the charger would be in Current Control mode at 50A and not moving from there.

As a reference example I have temporary Cabling in my Garage (2 x 16mm2 in parallel on each Polarity, approx 10 meters Length, for each Battery and for each Inverter). Charger is single 16mm2 Cable.

With the Charging Voltage of 55.3 VDC set by the Inverter, I barely can exceed 60A / Battery. I'll never reach 100A / Battery because the voltage drop (at 100A) is simply too much. And the Batteries are roughly 54 V-ish most of the Time.

I tried a short-term Experiment: increase the Charge Voltage to 56.0 VDC. Then I see 100 A. Of course that needs much better Software Control near the end of the Charge Curve, so I went immediately back to 55.3 VDC.

So if you CANNOT reach the 50A, one Thing to check is: make your Schematic, draw your Wires, calculate the Resistance of each Path and check the Delta Voltage between Battery and Charger/Inverter. Changes is you'll find that there is just NOT enough Voltage Difference provided by the Charger/Inverter to compensate for the High-ish Resistance of your Cables/Connections. NOT necessarily a Bad Connection (although it could also be).

 

[42OhmsPA]

With the wires you have in your circuit, it might simply be a case of Ohm's Law .

If your current is BELOW 50A, then the Charger is in Voltage Control mode. That's the case near the Top of the Charge Curve OR if your Wire/Connection Resistance is quite high. Otherwise, the charger would be in Current Control mode at 50A and not moving from there.

As a reference example I have temporary Cabling in my Garage (2 x 16mm2 in parallel on each Polarity, approx 10 meters Length, for each Battery and for each Inverter). Charger is single 16mm2 Cable.

With the Charging Voltage of 55.3 VDC set by the Inverter, I barely can exceed 60A / Battery. I'll never reach 100A / Battery because the voltage drop (at 100A) is simply too much. And the Batteries are roughly 54 V-ish most of the Time.

I tried a short-term Experiment: increase the Charge Voltage to 56.0 VDC. Then I see 100 A. Of course that needs much better Software Control near the end of the Charge Curve, so I went immediately back to 55.3 VDC.

So if you CANNOT reach the 50A, one Thing to check is: make your Schematic, draw your Wires, calculate the Resistance of each Path and check the Delta Voltage between Battery and Charger/Inverter. Changes is you'll find that there is just NOT enough Voltage Difference provided by the Charger/Inverter to compensate for the High-ish Resistance of your Cables/Connections. NOT necessarily a Bad Connection (although it could also be).

Thank you.
That makes sense, 2 years ago my head would have been spinning, what an amazing forum.

 

[silverstone]

Thank you.
That makes sense, 2 years ago my head would have been spinning, what an amazing forum.

At the end of the Day, Power Electronics is just Ohms Law (although using Complex Impedances instead of Resistances) as well as Kirchoff's 2 Laws (Sum of Voltages around a Loop = 0V and Sum of Currents at a Node = 0A) plus maybe how you calculate Power and Energy (P = U*I*cops(phi) and E = integral of P). It can get VERY Complicated (and Complex Numbers) with several equations and Variables, but it's still quite simple in Terms of Fundamentals.

Essentially with these 3-5 Laws you can analyze Any Circuit in Power Electronics. Start Simple. Draw your Diagram. Mark Current and Voltages. And take it from there. I'm not saying it's always easy and you definitively will make mistakes (especially on the +/- SIGN) or over-simply at the beginning, put stuff in parallel except of series etc. But it's something that everybody can understand.

When you go into Analytical or Finite elements analysis on Electromagnetic Fields, RF, etc, then it's a different Thing with Faradays Law, near/far Field, etc .

 

[silverstone]

@42OhmsPA: by the way, you "expected" to be limited to 25A ... Unless you set the limitation in software, the Limit is going to be determined based on the Voltage Difference and the Cabling/Connection Resistance.

Essentially: you need Volts to push Amps .

And if your AC 120V Grid or Generator is limited to a lower Rating that what you are pulling, it might get damaged or the Breaker there (hoping that you have one !) would trip, after a while (hopefully). It will NOT limit what the Charger can pull (minus some limitation on e.g. the Inrush Current at startup to charge Capacitors, but that's a very short term Event).

The Limit is given by a) Software Regulation (if any) and b) The System Impedance/Resistance. If a Protection kicks in at a later stage (e.g. Breaker tripping or Fuse melting), that's a separate issue. It's not limiting you in the short-medium Term (unless you have a short-circuit).

Key Point: Limit != Protection. If Protection << Limit you get nuisance trip. if Protection >> Limit, you'll never Trip. It's a whole Compromise and Coordination Discussion that needs to be done on System Level.

 

[silverstone]

Another piece arrived. Fits the back of the flatpack nicely.
I would love to fab a nice enclosure for it, but I have no skills or tools to do so, so it will likely live bolted to the side of my battery shelf in some form or another.

View attachment 209927
View attachment 209930

Now just waiting for the control board/display.

It actually looks way nicer than the Emerson PCB, especially with Regards to the CANBus connection (but also the Power Terminals).

I bought a few terminals/pins for the CANbus Connection for the Emerson, but still need to test if they work as expected.

It's definitively easier to have a VIA to put some Header through, rather than just a PAD on the Emerson.

Hope your AC N/L/PE terminals are properly Insulated though ...

 

[42OhmsPA]

@42OhmsPA: by the way, you "expected" to be limited to 25A ... Unless you set the limitation in software, the Limit is going to be determined based on the Voltage Difference and the Cabling/Connection Resistance.

Essentially: you need Volts to push Amps .

And if your AC 120V Grid or Generator is limited to a lower Rating that what you are pulling, it might get damaged or the Breaker there (hoping that you have one !) would trip, after a while (hopefully). It will NOT limit what the Charger can pull (minus some limitation on e.g. the Inrush Current at startup to charge Capacitors, but that's a very short term Event).

The Limit is given by a) Software Regulation (if any) and b) The System Impedance/Resistance. If a Protection kicks in at a later stage (e.g. Breaker tripping or Fuse melting), that's a separate issue. It's not limiting you in the short-medium Term (unless you have a short-circuit).

Key Point: Limit != Protection. If Protection << Limit you get nuisance trip. if Protection >> Limit, you'll never Trip. It's a whole Compromise and Coordination Discussion that needs to be done on System Level.

Thank you for all the help and explanations.

Yes, the AC side was protected with a breaker.
I need to build out a box with some DIN rail breakers for additional protection when I'm charging from the generator.

I also need to re-read the thread and get communication setup so I can make adjustments and tell the Emerson what to do.

It's all a journey towards eventually being off the grid on top of a mountain somewhere.

 

[silverstone]

I'd like to hear the Experiences from some of you ... Especially @upnorthandpersonal since you seem to be the one that played the longest with them (Emerson/Vertiv R48 3000W).

Today I was in the Garage and I could hear "something weird" near the Battery. Like some Sparks / small Arcing / maybe Buzzing-like noise but high-ish Pitch. I turned off the Chargers because you cannot really hear anything with their Fans running. Then the noise disappeared. Turned Charger on again, the noise came back.

Visually I couldn't see anything, neither Inside (looking from the Backside), nor Outside (on the Adapter PCB). Load was non-existent / very low since the Battery Voltage was above the Charger Voltage Set Point.

And while my Ear is not really a good Tracer by any means (and getting worse the older I get), I'd take a Wild Guess that it was coming "towards the back", possibly on the PCB Copper Traces - Connector Interface on the back of the Charger.

Given the low-Load situation at that Time, this definitively looks weird. Series Arcs usually require relatively high Currents and the load current at the time was probably < 0.2 AAC / < 2 ADC. Parallel Arcs usually means a Faulty Design (or e.g. Metal Chips bridging Insulation Barriers, Failure of Cables Insulation, etc), but those Devices should have passed a Factory HiPot Test ...

I'd say that both the Chargers that are currently Operating are affected. I don't feel it's Coil Whining. Maybe Discontinuous Current Conduction Mode and/or some weird PFC-related Harmonics at Low-Load causing this weird /pulsating Noise ?

Did anybody else observe this ?

 

[upnorthandpersonal]

Did anybody else observe this ?

Sorry, can't say that I have...

 

[silverstone]

Sorry, can't say that I have...

Should I try to record a Audio and try to upload it ? I might need to filter the fan noise though ...

@upnorthandpersonal: You might only be able to notice it well if you put one of your ears like 30cm away from the back of the Charger ...

Alternative would be to do a HiPot test but I'd rather not go there (rewiring etc).

 

[upnorthandpersonal]

I'll give it a try - I need to do a test run on the generator one of these days anyway.

 

[silverstone]

I'll give it a try - I need to do a test run on the generator one of these days anyway.

You could also just connect it to the output of the Inverter (but yeah, don't lose time on that, I can wait for the Generator) ... IIRC the Issue was at no-load/extremely low-load.

 

[Warpspeed]

Next time you hear that noise, try placing a piece of rubber or plastic tube to one ear and go hunting for the source with the free end.

I was caught out recently with a couple of adjustable 0 to 15v dc 500 watt switching power supplies purchased from China.
I thought they might be useful as a general bench power supply.

All of these types of supplies have some kind of fast current limit or overload protection.
Most just slide into constant current mode, and that is fine for most of our applications, and particularly useful for battery charging.

But very occasionally these supplies use a foldback current limit. When you reach max rated current, the supply drastically reduces both voltage and current together, and the supply locks up into a low dissipation mode to protect it from a dead short circuit on the output.

You need to switch it off, and then on again, to get it back working.
Fine for many applications, but a total disaster for battery charging or general test bench use.
So before dumping a lot of cash into a monster bargain switching power supply, its probably a good idea to read the fine print in the specifications about the type of current limit and find out exactly how it works.

 

[BarracudaBob]

The Ham Radio guys have been modifying "rectifiers" for their Solid State LDMOS Amplifiers. The small Flatpack2 are nice little units.

HP ESP 120 Power Supply​

 

[42OhmsPA]

Did anybody else observe this ?

I'll pay attention next time I'm using mine, unfortunately I hope that isn't for a long time...

 

[BarracudaBob]

Has anybody looked at this 40A charger. Seems like a modification of voltage would make a nice universal charger $179.99

​

 

[silverstone]

Next time you hear that noise, try placing a piece of rubber or plastic tube to one ear and go hunting for the source with the free end.

I was caught out recently with a couple of adjustable 0 to 15v dc 500 watt switching power supplies purchased from China.
I thought they might be useful as a general bench power supply.

All of these types of supplies have some kind of fast current limit or overload protection.
Most just slide into constant current mode, and that is fine for most of our applications, and particularly useful for battery charging.

But very occasionally these supplies use a foldback current limit. When you reach max rated current, the supply drastically reduces both voltage and current together, and the supply locks up into a low dissipation mode to protect it from a dead short circuit on the output.

You need to switch it off, and then on again, to get it back working.
Fine for many applications, but a total disaster for battery charging or general test bench use.
So before dumping a lot of cash into a monster bargain switching power supply, its probably a good idea to read the fine print in the specifications about the type of current limit and find out exactly how it works.

I actually went again in the Garage yesterday for another Thing. And of course I couldn't hear it at that Time .

But to be Fair, the Battery Voltage might have been quite different (it was Fully Charged yesterday when I checked again in the Garage) ... IIRC when I saw the Issue, the Battery Voltage was maybe 52-53 VDC (as opposed to 54-55 VDC). Small Difference but can of course influence the Duty Cycle etc.

If it's NOT a real Problem, Chances are that it's just some "low-frequency" "Pumping" of the DC Capacitor since the load is so small (essentially Fan + Controller + some Losses) and for some Reason that generates a high-ish Pitch Noise (maybe PFC/Harmonics doing that).