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aceclement asked

Relay switch for an inverter to be shut off by the battery protect

I am confused about how I can use my battery protect to shut off my inverter when low voltage occurs. I understand that I should not connect the inverter to the battery protect and that I can instead wire the inverter remote on off switch ground to the alarm terminal and the positive to the battery protect positive. But that doesn't seem to shut off the inverter as it should. Does that mean the battery protect does not have a relay switch inside and I need to wire on myself? If so, can someone help me out and show me what I need to buy and how to connect it. At least what I need to buy and I can research how to do it. I really wish the battery protect manual was more detailed and specific on the topic. Thank you in advance.

Battery Protect
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Vance Mitchell avatar image Vance Mitchell commented ·
What Inverter do you have? Does it have a remote switch option? Once we know what you are working with it will be easier to advise on your options.
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Vance Mitchell answered ·

If you have been able to successfully turn your inverter on/off with a remote switch you should be able to replace the switch with a relay.

On a standard automotive relay you would connect the two wires that are currently on your switch to pins 30 and 87 on the relay. 85 would go to your negative bus bar, and 86 would be connected to switched power ( In this case the output from the battery protect). This will turn the relay on any time there is power coming the battery protect and will turn the relay off if the battery protect shuts its output off.

There is also the option of connecting the relay to the smaller terminals on the battery protect, but I would have to check the manual for how that works.

If you still want a seperate switch to turn the inverter off as well it can be cut into the wire going to 86.

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aceclement avatar image aceclement commented ·

Just before I read your reply I figured it out. Thank you so much for taking the time to respond. What I figured out is pin 30 gets a fuse and is connected to the positive terminal closest to the remote pins on the battery protect. Then the blue ground pin 85 on the relay goes into the alarm pin on the battery protect, then the white/ground from the inverter remote switch goes to the green 86 pin of the relay, finally the red load from the inverter remote switch goes to a positive battery terminal, but not to the battery connection terminal or a terminal where the main positive goes to the inverter form the battery. The yellow87 and Orange87a go to nothing. Boom! Poor choice of words there but it works perfectly now.


I can't tell you how relieved I am that i finally did it correctly after so many attempts.

Here is a video I made about it to help others. https://youtu.be/KOl12gB-vYk


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Vance Mitchell avatar image Vance Mitchell aceclement commented ·
What you have described seems odd.

A relay works like a switch, pin 85 and 86 go to an electromagnet which causes the switch to change state.

When no power is applied to the coil (electromagnet) pin 30 connects to 87a, when power is applied, pin 30 connects to 87.

If you have nothing connected to 87 or 87a then the relay shouldn’t be actually switching anything.

From what you have described the fused power wire to pin 30 is not actually doing anything, if you have a chance could you try disconnecting it and letting me know what happens?


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aceclement avatar image aceclement Vance Mitchell commented ·
Sure ill try that. It will take me several days to get back to you as we are leaving to go camping today. You may be correct about that 30 pin. At this point it is working as intended. We shall see. Hey thanks again. I really appreciate your input.
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