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EG4 Chargeverter Battery/Inverter Communications

If you have SOC, can't you use that to turn charging on and off instead of using voltage? Or am I misunderstanding and all the "ON" and "OFF" things do (either voltage or SOC) is control when the dry contacts are open or closed...
Yes, that is what I understand to be correct
 
Well ok then. Went back and read the thread, sounds like if AC power is applied, then it charges. Marion built an external box to turn AC power on and off to the CV, maybe I will need to do the same thing :fp2
 
Since I am not familar on how you have your whole system configured, I m not much help to your last message.. there may be other here on DIY will chime in and shed more light.. as I am not sure all your trying to accomplish.. be smart and stay safe..
 
SA seems to work using either pins 1&2 or 7&8 as best I can tell... (with Lifepower4 V1 batteries)
Although SA can use pins 7&8, however if you have a "Master" battery (address 0) then there will be a conflict on pins 7&8 as the "Master" and SA would both be trying to use the same bus.

The CV-GC is hardwired to use pins 1&2 and it only uses SOC to drive the dry contacts. Many on this forum have developed solutions using a contactor (like what is used in an HVAC unit) to control power to the CV-GC with lower power (i.e. 12vdc) circuitry. Same circuit could be used to control an auto-start generator. In addition many AIO and some batteries have programmable "dry contacts" that can be used.

As long as the CV-GC has input AC power it is in charge mode. It will only charge when it's output voltage setting is greater than the battery voltage. With AC input always ON the CV-GC would be providing power to the batteries AND the inverter depending on load. You only want to provide AC input power to the CV-GC when you need to charge the batteries and/or provide power to the inverter while charging the batteries.

For example; When I power the CV-GC from my generator (actually two CV-GC) they charge the batteries and provide the power via the battery bus to the inverter so I am indirectly powering the house from the generator.

If I were to power the CV-GC from the grid I would essentially be powering the inverter and it's loads from the grid and depending on the inverter load I would also charge the batteries. This is fine for those who do not want the AIO connected in any way to the grid but need an additional way to charge batteries

The CV-GC only needs to be powered on when you need to charge the batteries. How you control that power and where it comes from is up to you.
 
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As long as the CV-GC has input AC power it is in charge mode. It will only charge when it's output voltage setting is greater than the battery voltage.

And is it true that if it has an SOC value from the batteries, then it will only charge when the SOC is less than the SOC "target", ie when the SOC is less than the value in the "SOC START" field?
 
And is it true that if it has an SOC value from the batteries, then it will only charge when the SOC is less than the SOC "target", ie when the SOC is less than the value in the "SOC START" field?
Yes, what a pain if you are really off grid because,
if you want any power from the generator to be used for charging you have to be within the min/max range, so I set mine to 90min/95max, if I'm running the generator why waste the diesel. There is no 'charge now' button and if we do go away one has to reset the SOC/VOL not so aggressively like 30-98%SOC. There are discrepancies between SOC/VOL as many folks have pointed out on this form so to be able to

Also there is no GEN start/stop time, only AC TOD start/stop settings. (thought this was an off grid product)
 
And is it true that if it has an SOC value from the batteries, then it will only charge when the SOC is less than the SOC "target", ie when the SOC is less than the value in the "SOC START" field?
If the CV-GC has AC input power then it is in "Charge" mode" and the DC output is always "ON" regardless of any "Start" or "Stop" settings. The Start" or "Stop" settings are only used to determine when the CV-GC activates the "dry contacts"

The "dry contacts" can be used to auto start a generator or activate a contactor or other device that controls the AC input to the CV-GC. As long as the CV-GC DC output is connected to the batteries and the DC breaker is closed the CV-GC is powered on and "Idle"

In my case I have a small case with a heavy duty contactor that controls grid AC input to the CV-GC. The contactor has a 23vac coil (same as is used by HVAC systems and the thermostat). I can use the "dry contacts" in the CV-GC to control the 23vac power to the contactor coil thus controlling grid power to the CV-GC. The CV-GC controls the "dry contacts" based on the Start" or "Stop" SOC setting or in the absence of an RS485 input the Start" or "Stop" voltage settings.
 
If the CV-GC has AC input power then it is in "Charge" mode" and the DC output is always "ON" regardless of any "Start" or "Stop" settings. The Start" or "Stop" settings are only used to determine when the CV-GC activates the "dry contacts"
Wow, I knew it was useless, and I knew I didn’t ever want to bother with any of those features, but I didn’t realize just how useless it was. At least the UI is nice and the ramp is a good feature. Sure would have made life a lot easier if there was a signal you could send to it to turn it on and off.
 
Wow, I knew it was useless, and I knew I didn’t ever want to bother with any of those features, but I didn’t realize just how useless it was. At least the UI is nice and the ramp is a good feature. Sure would have made life a lot easier if there was a signal you could send to it to turn it on and off.
It would also be nice if via a program you could set the various parameters such as charging voltage and current
 
It would also be nice if via a program you could set the various parameters such as charging voltage and current
Indeed, but it's not a responder, it's a host. So many things they could have done right, and instead we've got a box that nearly everyone adds relays to the AC input on. 🤷‍♂️
 
In my setup, I'll be using grid power exclusively on the AC In. I purchased the CV thinking the batt start batt stop actually controlled the voltage swing, but I guess not when it's on grid without fooling it. Not the end of the world, I guess. So if I set the CV to 51.5-52V it looks like it should only draw enough power to keep it there and keep my loads powered off the battery bank at a low SOC safe enough to absorb spikes and function as a few hours worth of UPS. Then my solar charge controllers will be free to charge up to 100% SOC, which will be above the voltage supplied by the CV, meaning the CV power will drop to near-0 (other than what it needs to "idle). Hopefully I am understanding this right, as it's what I was banking on to maximize the amount of solar I can use and minimize the grid charging.
 
Hopefully I am understanding this right, as it's what I was banking on to maximize the amount of solar I can use and minimize the grid charging.
Yes, this is correct. Set the CV to a relatively low voltage (51-52V depending on your personal acceptable low SOC tolerance) to just prevent the batteries from completely discharge. The CV will not provide power if the battery voltage rises above this value (e.g. because of PV is charging in parallel).
 
Yes, this is correct. Set the CV to a relatively low voltage (51-52V depending on your personal acceptable low SOC tolerance) to just prevent the batteries from completely discharge. The CV will not provide power if the battery voltage rises above this value (e.g. because of PV is charging in parallel).
Great thanks! On second thought this is actually better because I was worried about the 5v swing minimum between start and stop. I would have had to let it get fairly low SOC if I wanted less than 52v as my holding-point until the sun comes back out. Do you happen to know what the low-voltage shut-down voltage is? I didn't see it in the manual. This would be in case the generator fails to start, or the grid goes down. I don't want to run into the BMS low voltage shutdown, since that's supposed to be an extreme minimum voltage. The 10 watts the CV takes at idle is actually significant when the batteries are down to <5% SOC. Plus, then I'd have to restart the BMS which would be a whole PITA.
 
Great thanks! On second thought this is actually better because I was worried about the 5v swing minimum between start and stop. I would have had to let it get fairly low SOC if I wanted less than 52v as my holding-point until the sun comes back out. Do you happen to know what the low-voltage shut-down voltage is? I didn't see it in the manual. This would be in case the generator fails to start, or the grid goes down. I don't want to run into the BMS low voltage shutdown, since that's supposed to be an extreme minimum voltage. The 10 watts the CV takes at idle is actually significant when the batteries are down to <5% SOC. Plus, then I'd have to restart the BMS which would be a whole PITA.
I don't know the low-voltage shut-down value of the EG4 CV (I don't own the EG4 CV, instead I've DIY my own chargeverter based on Huawei R4875G1, but the working principle is the same).

But I'm not sure if I understand your question correct. So far I thought you don't use the EG4 CV with closed loop communication (using just programmed voltages to control the CV)?! In this case, a low-voltage shutdown of the CV would not really prevent your batteries to run in an under voltage situation - it would just shutdown the CV. Usually, your inverters will shutdown before the batteries are running in an under voltage situation where the BMS shuts them off - either by a low voltage setting in your inverter or, in case you use closed loop communication between battery in inverter, depending on the low cut-off SOC settings in your inverter.
As far as I know, the CV is not able to tell your inverters to shutdown (not longer using batteries) because the CV don't have grid/generator power available... this would not make sense, because the inverters are the "consumers" of your battery and to prevent a deep discharge, the inverters have to stop using the batteries... but as I said, I don't own the EG4 CV...
 
I don't know the low-voltage shut-down value of the EG4 CV (I don't own the EG4 CV, instead I've DIY my own chargeverter based on Huawei R4875G1, but the working principle is the same).

But I'm not sure if I understand your question correct. So far I thought you don't use the EG4 CV with closed loop communication (using just programmed voltages to control the CV)?! In this case, a low-voltage shutdown of the CV would not really prevent your batteries to run in an under voltage situation - it would just shutdown the CV. Usually, your inverters will shutdown before the batteries are running in an under voltage situation where the BMS shuts them off - either by a low voltage setting in your inverter or, in case you use closed loop communication between battery in inverter, depending on the low cut-off SOC settings in your inverter.
As far as I know, the CV is not able to tell your inverters to shutdown (not longer using batteries) because the CV don't have grid/generator power available... this would not make sense, because the inverters are the "consumers" of your battery and to prevent a deep discharge, the inverters have to stop using the batteries... but as I said, I don't own the EG4 CV...
My Inverter will shutdown based on low voltage. But it seems the CV is drawing power from the battery to keep its management circuitry active to know when to turn on the generator, etc. That would happen outside of the jurisdiction of every low voltage shutdown except the BMS.
 
My Inverter will shutdown based on low voltage. But it seems the CV is drawing power from the battery to keep its management circuitry active to know when to turn on the generator, etc. That would happen outside of the jurisdiction of every low voltage shutdown except the BMS.
Yes, it's frightfully shortsighted and dumb of Eg4 to not have an eco mode or LV shutdown of the chargeverter.
 
Yes, it's frightfully shortsighted and dumb of Eg4 to not have an eco mode or LV shutdown of the chargeverter.
I just messaged their support to confirm whether it does or doesn't have LV shutdown. I am hoping I'm just overlooking something where it'll turn off at some threshold below the batt_start point, once it detects there is no AC input happening.
 
As long as the CV-GC has battery input (breaker closed) the CV-GC will remain on and monitor the battery voltage as measured at it's battery cables. The CV-GC is looking for the battery voltage to drop to the "Bat Start" setting (Or "SOC Start" setting if communications is hooked up to the "Master" battery) at which time the CV-GC will close it's "Dry Contacts" thinking it is starting a generator.

The sole purpose of the "SOC Start", "SOC Stop", "Bat Start" and "Bat Stop" is for "Dry Contact" control. nothing else. As long as the CV-GC has AC power it will provide charge power when the battery voltage is less than the "Voltage" setpoint of the CV-GC, regardless of the "SOC Start", "SOC Stop", "Bat Start" and "Bat Stop" settings.

The communications between the CV-GC and the "Master" battery is only for the CV-GC to know what the battery stack SOC is. This only works with certain EG4 batteries.

Without AC input the CV-GC will do nothing but (with the breaker closed) monitor the battery.

Many folks have opted to use the "Dry Contacts" to instead of starting a generator, control an HVAC/Motor type "Contactor" (heavy duty 120/240vac relay) to control the AC input to the CV-GC. The CV-GC will with it's AC input hot, charge the batteries until the battery voltage (Or SOC; "SOC Stop") reaches the "Bat Stop" setting.

While the CV-GC has AC input it will charge the batteries AND provide input power to the Inverter as long as the battery voltage is less then the CV-GC Voltage setpoint. If the CV-GC always has AC input power available (i.e. permanently plugged into an AC outlet) and the battery voltage is lower than the Voltage setpoint, the CV-GC will provide charge power which means that under many conditions you are essentially running the Inverter on Grid input via the CV-GC.
 
As long as the CV-GC has battery input (breaker closed) the CV-GC will remain on and monitor the battery voltage as measured at it's battery cables. The CV-GC is looking for the battery voltage to drop to the "Bat Start" setting (Or "SOC Start" setting if communications is hooked up to the "Master" battery) at which time the CV-GC will close it's "Dry Contacts" thinking it is starting a generator.

The sole purpose of the "SOC Start", "SOC Stop", "Bat Start" and "Bat Stop" is for "Dry Contact" control. nothing else. As long as the CV-GC has AC power it will provide charge power when the battery voltage is less than the "Voltage" setpoint of the CV-GC, regardless of the "SOC Start", "SOC Stop", "Bat Start" and "Bat Stop" settings.

The communications between the CV-GC and the "Master" battery is only for the CV-GC to know what the battery stack SOC is. This only works with certain EG4 batteries.

Without AC input the CV-GC will do nothing but (with the breaker closed) monitor the battery.

Many folks have opted to use the "Dry Contacts" to instead of starting a generator, control an HVAC/Motor type "Contactor" (heavy duty 120/240vac relay) to control the AC input to the CV-GC. The CV-GC will with it's AC input hot, charge the batteries until the battery voltage (Or SOC; "SOC Stop") reaches the "Bat Stop" setting.

While the CV-GC has AC input it will charge the batteries AND provide input power to the Inverter as long as the battery voltage is less then the CV-GC Voltage setpoint. If the CV-GC always has AC input power available (i.e. permanently plugged into an AC outlet) and the battery voltage is lower than the Voltage setpoint, the CV-GC will provide charge power which means that under many conditions you are essentially running the Inverter on Grid input via the CV-GC.
Got all that. Thanks! It wasn't how I thought it worked when I ordered it but that's OK. I'm really more worried about the power it uses to monitor battery voltage and to close the dry contacts in case the generator doesn't start (or grid goes down, in my case). That idle power albeit small will drag the cell voltage down to the bms LV disconnect setpoint eventually if it has no low-dc cutoff if no AC input detected. 10 watts idle, stated in the manual is about all I'm comfortable with if I can't make it "give up" at say, 43v when there's no AC input. It's gotta make it thru the night until the sun comes out to start recharging off solar - could be 14 hours in the winter which would be 1% SOC lost in that timeframe. It's an edge case, but its a consideration that would require manual intervention to restart the system if the BMS turns off, which could be annoying if it happens while I'm out of town, etc.
 
Got all that. Thanks! It wasn't how I thought it worked when I ordered it but that's OK. I'm really more worried about the power it uses to monitor battery voltage and to close the dry contacts in case the generator doesn't start (or grid goes down, in my case). That idle power albeit small will drag the cell voltage down to the bms LV disconnect setpoint eventually if it has no low-dc cutoff if no AC input detected. 10 watts idle, stated in the manual is about all I'm comfortable with if I can't make it "give up" at say, 43v when there's no AC input. It's gotta make it thru the night until the sun comes out to start recharging off solar - could be 14 hours in the winter which would be 1% SOC lost in that timeframe. It's an edge case, but its a consideration that would require manual intervention to restart the system if the BMS turns off, which could be annoying if it happens while I'm out of town, etc.
Heck, When I ordered mine I thought "RS485", I can software control the thing. Boy was I disappointed.
I did build a contactor box controlled by the CV-GC Dry contacts that will provide 240vac power to the CV-GC when the battery voltage drops below the "Bat Start" voltage. This setup works

BTW: many batteries and inverters also have "Dry" contacts for the same purpose.
 
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As long as the CV-GC has battery input (breaker closed) the CV-GC will remain on and monitor the battery voltage as measured at it's battery cables. The CV-GC is looking for the battery voltage to drop to the "Bat Start" setting (Or "SOC Start" setting if communications is hooked up to the "Master" battery) at which time the CV-GC will close it's "Dry Contacts" thinking it is starting a generator.

The sole purpose of the "SOC Start", "SOC Stop", "Bat Start" and "Bat Stop" is for "Dry Contact" control. nothing else. As long as the CV-GC has AC power it will provide charge power when the battery voltage is less than the "Voltage" setpoint of the CV-GC, regardless of the "SOC Start", "SOC Stop", "Bat Start" and "Bat Stop" settings.

The communications between the CV-GC and the "Master" battery is only for the CV-GC to know what the battery stack SOC is. This only works with certain EG4 batteries.

Without AC input the CV-GC will do nothing but (with the breaker closed) monitor the battery.

Many folks have opted to use the "Dry Contacts" to instead of starting a generator, control an HVAC/Motor type "Contactor" (heavy duty 120/240vac relay) to control the AC input to the CV-GC. The CV-GC will with it's AC input hot, charge the batteries until the battery voltage (Or SOC; "SOC Stop") reaches the "Bat Stop" setting.

While the CV-GC has AC input it will charge the batteries AND provide input power to the Inverter as long as the battery voltage is less then the CV-GC Voltage setpoint. If the CV-GC always has AC input power available (i.e. permanently plugged into an AC outlet) and the battery voltage is lower than the Voltage setpoint, the CV-GC will provide charge power which means that under many conditions you are essentially running the Inverter on Grid input via the CV-GC.
After reading your explanations, I'm really happy that I've gone the DIY Chargeverter path instead of using the CV-GC (which I had considered first). With the own ESP32 CAN Bus controller, I can do what I want and when I want with them.
These units have usually an hibernate (OFF) mode which I use if I don't need them. In this mode they draw nearly no power (no fans are spinning), but the CAN communication is still working! I'm sure the rectifiers used inside the CV-GC are also able to do this. I don't understand why they are not using this feature...
 
The sole purpose of the "SOC Start", "SOC Stop", "Bat Start" and "Bat Stop" is for "Dry Contact" control. nothing else. As long as the CV-GC has AC power it will provide charge power when the battery voltage is less than the "Voltage" setpoint of the CV-GC, regardless of the "SOC Start", "SOC Stop", "Bat Start" and "Bat Stop" settings.
That’s the unbelievable part. Not that I don’t believe you, I don’t believe EG4 specified a product with such poor functionality.
 

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