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victron battery protect not working as expected

I use the alarm contact to trigger locking relay. locking relay can off any device. I use it for the AC side of the inverter and the thermostat of the furnace. The furnace must run on for a few to clear the chamber. The inverter doesn't want to shut off under load.
 
OK, investigation complete ... don't use the 'Remote' connections. These are solely for turning the BatteryProtect on or off i.e. just a master of/off switch. You need to use the Alarm terminal.

The Alarm terminal basically provides a ground return when it activates i.e. depending on voltage IN and whatever programme is selected:

View attachment 21727

And your inverter's (when switch to EXT) Terminal Block 4a has an opto-coupler that is seeking a power supply referenced to an independent ground in order to activate:

View attachment 21728

So you should be able to mary-up the ground-seeking circuit to the ground-providing circuit to control the inverter either by:
  1. Providing a ground for the in-built supply that I assume is offered on terminal 'S' (Option 1) OR
  2. Provide both supply and ground to terminals '+' and '-' (Option 2)
View attachment 21734

Now unfortunately, this will turn the inverter on when the BatteryProtect tells it to turn off!! I'm working on that, but for now, my brain is mush - I need some sleep!!

Actually I tried it again and option #2 works nicely.
There were 2 changes since last I tried it.
1. I put the converter in constant voltage mode.
2. I disconnected the converter equipment ground.

@tictag thanks for your excellent support on this.
In my estimation the Battery protect has only 2 black marks now ;)
 
And your inverter's (when switch to EXT) Terminal Block 4a has an opto-coupler that is seeking a power supply referenced to an independent ground in order to activate:

Not quite sure I understand "referenced to an independent ground".
 
Not quite sure I understand "referenced to an independent ground".
According to the manual on page 52, the '-' terminal of the opto-coupler is not grounded internally, so it must be provided with an independent ground i.e. one external to the inverter:

2020-09-03_23-11-23.png
 
Actually I tried it again and option #2 works nicely.
Crikiebobs, I figured that would switch the inverter ON when the BatteryProtect activated on low voltage ... exactly the opposite of the required behaviour! But, hey, if it works, it works!
 
According to the manual on page 52, the '-' terminal of the opto-coupler is not grounded internally, so it must be provided with an independent ground i.e. one external to the inverter:

View attachment 21822
Why does the manual show the third option with just a fused link to the + ?
 
I'm not sure, tbh, I kinda imagined the opto-coupler circuitry to be something like this:

opto.png

Where an independent supply and ground would activate the opto-coupler and switch the device on, but that wouldn't obviously work with only a supply present on '+'.
 
Did a bit more poking around.
Actually I tried it again and option #2 works nicely.
There were 2 changes since last I tried it.
1. I put the converter in constant voltage mode.
2. I disconnected the converter equipment ground.

Did a bit more poking around.
There was one more change.
I had added a hall effect sensor monitor and the display part was drawing through the battery protect.
In the meantime I attached the battery monitor upstream because I don't want it disconnected by the battery.
And... the battery protect disgraced itself.
Added a buck converter downstream of the battery protect and things are working as expected.
 
OK, investigation complete ... don't use the 'Remote' connections. These are solely for turning the BatteryProtect on or off i.e. just a master of/off switch. You need to use the Alarm terminal.

The Alarm terminal basically provides a ground return when it activates i.e. depending on voltage IN and whatever programme is selected:

View attachment 21727

And your inverter's (when switch to EXT) Terminal Block 4a has an opto-coupler that is seeking a power supply referenced to an independent ground in order to activate:

View attachment 21728

So you should be able to mary-up the ground-seeking circuit to the ground-providing circuit to control the inverter either by:
  1. Providing a ground for the in-built supply that I assume is offered on terminal 'S' (Option 1) OR
  2. Provide both supply and ground to terminals '+' and '-' (Option 2)
View attachment 21734

Now unfortunately, this will turn the inverter on when the BatteryProtect tells it to turn off!! I'm working on that, but for now, my brain is mush - I need some sleep!!
I just bought a Victron Battery Protect on Amazon and NOTHING in the description on Amazon even mentioned anything about not using it to control an inverter and I carefully read the whole thing. When it arrived, I read ALL of the accompanying documents provided by Victron and, again, not one mention of not using it to control an inverter. Of course it did not work and wasted my day trying. I contacted Amazon and they are reimbursing me for the purchase and the Battery Protect unit is going back to them intact but possibly damaged. That is their problem though since using one of these things to disconnect an inverter is a pretty intuitive function and Victron should have a seriously obvious warning both in their sales material AND especially in their user manuals. They can of course be used to control the bms remotely, but in my case I do not have access to my bms units and opening the power supply source is the only option left outside of opening the AC output. So my plan going forward is to attempt control a heavy duty automotive starter relay with a low current under voltage cut off unit. There certainly needs to be something on the market that can monitor battery voltage and cut power to inverters. But apparently the problem with Battery Protect is they use solid state current control rather than old fashioned mechanical switching devices.
 
I just bought a Victron Battery Protect on Amazon and NOTHING in the description on Amazon even mentioned anything about not using it to control an inverter and I carefully read the whole thing. When it arrived, I read ALL of the accompanying documents provided by Victron and, again, not one mention of not using it to control an inverter. Of course it did not work and wasted my day trying. I contacted Amazon and they are reimbursing me for the purchase and the Battery Protect unit is going back to them intact but possibly damaged. That is their problem though since using one of these things to disconnect an inverter is a pretty intuitive function and Victron should have a seriously obvious warning both in their sales material AND especially in their user manuals. They can of course be used to control the bms remotely, but in my case I do not have access to my bms units and opening the power supply source is the only option left outside of opening the AC output. So my plan going forward is to attempt control a heavy duty automotive starter relay with a low current under voltage cut off unit. There certainly needs to be something on the market that can monitor battery voltage and cut power to inverters. But apparently the problem with Battery Protect is they use solid state current control rather than old fashioned mechanical switching devices.
My guess is that this problem only occurs with lithium batteries.
 
Perhaps this thread will help:


@rhino may have the answer with the battery protect he is using?
 
Thanks! I am already thinking along those lines. Seemingly that would require a momentary "signal" though, and how one would achieve that is the question. I have yet to see any documentation from Victron suggesting that any of their devices are capable of that. The inexpensive device I have on order is capable of doing either a closed circuit or an open circuit when voltage reaches a certain level and in far less expensive than the Victron device, but the question remains, can I shut down the inverter with a simple shorting or opening of one of the pairs on the remote unit?
 
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