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victron battery protect not working as expected

John Frum

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Victron bp-65

to reproduce:

make this setup:
battery.pos->fuse->bp_in->bp_out->fuse->inverter_ext_switch_terminal
battery.neg<-bp_pin_1.2_ground
Set the power switch on the inverter to external switching mode

baseline: Open the fuse between bp_out and inverter_ext_switch_terminal
notice the inverter turns off
reset for test

test: remove the short between remote 2.1 and remote 2.2
Expected results: the inverter should shut off
Observed results: the inverter does not shut off

Is my test valid?
How can I make the battery protect shut down my inverter?
 
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Battery positive -> fuse -> Battery protect,in -> battery protect,out -> inverter,+. On low voltage; Alarm at 12 seconds, shut down at 90 seconds more. That is almost 1 3/4 minutes. I got around that with latching relay from alarm terminal (on a different brand). I also use relays to disconnect the 120V load from the inverter before shut down.
 
I heard back from Victron and they are aware that the low voltage disconnect leaks residual voltage on the downstream.
I'm currently exploring the possibility of replacing my fairly expensive and thrice hobbled Victron battery protect with a $20.00CAD pwm solar charge controller.
The cheap solar charge controller has a load port that with an LVD configurable to a 10th of a volt.
The cheapy charge controller has a better configuration interface to add insult to injury.

1. Can't tolerate bi-directional current.
2. Can't tolerate the in-rush associated with priming the caps in an inverter.
3. Low voltage disconnect doesn't really disconnect.

Victron is a good company with good products and good support but the Victron battery protect is the red headed stepchild of their product line.

To any redheads and/or step children, its a figure of speech and I mean no dis-respect.☮
 
Victron bp-65

to reproduce:

make this setup:
battery.pos->bp_in->bp_out->fuse->inverter_ext_switch_terminal
battery.neg<-bp_pin_1.2_ground
Set the power switch on the inverter to external switching mode

baseline: Open the fuse between bp_out and inverter_ext_switch_terminal
notice the inverter turns off
reset for test

test: remove the short between remote 2.1 and remote 2.2
Expected results: the inverter should shut off
Observed results: the inverter does not shut off

Is my test valid?
How can I make the battery protect shut down my inverter?
battery protect is for DC loads, put it inline to the dc fuse box. putting it inline to the inverter is NOT GOOD and can in fact destroy the battery protect. Will updated his diagrams to NOT include the battery protect.
 
ahh. I don't understand how that CC is used to switch the inverter off at low voltage.
 
ahh. I don't understand how that CC is used to switch the inverter off at low voltage.

The solar charge controller has load terminals which support configurable lvd disconnect/reconnect,
 
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Battery positive -> fuse -> Battery protect,in -> battery protect,out -> inverter,+.
You must not connect a BatteryProtect to the supply circuit of an inverter. Apparently, many BatteryProtects have been destroyed this way and, as this is clearly stated in the manual, it would be a very generous Victron to replace such units under warranty.


Whilst I personally have a BatteryProtect, I do not use it to switch off my inverter, but I always thought that it could and have on occasion recommended using it for such purposes to others on here. I'm going to look into this. Hope I don't end up with egg on my face :oops:.
 
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:

2020-09-03_02-45-05.png

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:

2020-09-03_02-46-42.png

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)
BP on-off.png

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!!
 
Or you could simply connect OUT to '+', but this assumes that no voltage is on OUT when the BatteryProtect has activated, and that's far from certain and anyway, floating terminals are no good if you want reliable activation. Although I guess you clamp OUT to ground with a high value resister, but then you'd have a constant, albeit small, drain on the battery... argghhh! ;)

OK, OK, now I'm going to sleep!! ?
 
Or you could simply connect OUT to '+', but this assumes that no voltage is on OUT when the BatteryProtect has activated, and that's far from certain and anyway, floating terminals are no good if you want reliable activation. Although I guess you clamp OUT to ground with a high value resister, but then you'd have a constant, albeit small, drain on the battery... argghhh! ;)

OK, OK, now I'm going to sleep!! ?
I've wired my Phoenix inverter remote to the out of the smart battery protect as shown in the Victron manual and I can confirm that it does not switch off the inverter. There is a voltage of 1.63v at the remote terminal when the battery protect is activated. This voltage is sufficient to allow the inverter to operate. This issue has been reported on several forums including the Victron Community. Victron's reply to me was ' we are working on a solution and should have an answer next week and in the meantime why not purchase a smart dongle and set the LVD via Victron Connect'. That was 2 months ago and so far no reply from Victron. Several people have suggested using a resister but there doesn't seem to be an agreed solution.
 
OK, I'm back. Had some very weird dreams...

But anyway, I can't think of a way to 'invert' the Alarm control signal without resorting to a relay per the middle diagram in the inverter's manual. So I think you've got another two options, the first will need to be tested:

3. Test whether the floating OUT terminal on activation is sufficiently stable to de-activate the opto-coupler (and turn the inverter off)
4. Use a relay to invert the Alarm control signal

BP on-off mark 2.png

OPTION 3

When the BP is in normal operation voltage VIN is available on OUT, opto-coupler is energised via '+' and '-' to ground. Very simple, but floating voltage on OUT might cause problems. The dotted line indicates an available ground, but any system ground will do.

OPTION 4

Here we're just inverting the Alarm signal through a relay. When the BP is in normal operation no ground is available to the Relay so the opto-coupler finds a supply via IN, through the Relay contacts to ground, activates and switches on the inverter. The dotted line indicates an available ground, but any system ground will do. When Alarm is triggered a ground becomes available to the Relay so it switches over, disconnecting the ground to '-', de-energising the opto-coupler and, therefore, switches off the inverter.

Option 3 is obviously a lot simpler so this would be preferable if your test is successful. Option 4 requires an additional, albeit cheap, component but should provide a more reliable activation.

Fuse should be 1A per your manual's guidance.
 
Oh, bugger!! Option 4 doesn't fail-safe. Hope Option 3 works!!

Thats the one I started with in post #1.

I've replaced the battery protect with a <$20.00 PWM controller and it works just fine.
Has a better user interface and much more granular voltage parameters.
I'll be using the same battery protect in a more standard setup in an upcoming project.
 
Thats the one I started with in post #1.
I thought you were using the Remote terminals? Had you also tried with the Alarm terminal? Sorry, must have missed that. Ahhh, you were using the remote terminals simply to activate the BP. Got it.

So you mention ...
battery.pos->fuse->bp_in->bp_out->fuse->inverter_ext_switch_terminal
battery.neg<-bp_pin_1.2_ground
When you say, "inverter_ext_switch_terminal" do you mean the terminal marked 'S' in your user manual? If so, that's not what I am suggesting in Option 3. There would need to be two wires going into Terminal Block 4a, one supply, one ground.
 
When you say, "inverter_ext_switch_terminal" do you mean the terminal marked 'S' in your user manual? If so, that's not what I am suggesting in Option 3. There would need to be two wires going into Terminal Block 4a, one supply, one ground.
 
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