automatic charging relay

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=121104
Printed Date: May 15, 2025 at 8:55 PM

Topic: automatic charging relay

Posted By: coolen
Subject: automatic charging relay
Date Posted: March 31, 2010 at 4:20 PM

I just got one of these: https://bluesea.com/category/2/productline/overview/387

it has a feature that when it sees 12v on the starter inturrupt input it isolates the batteries. My question is, if I took a switch and ran the wire to that Starter Inturrupt terminal, with the switch on would it keep my batteries isolated? Or is this just a bad idea??

Thanks

Replies:

Posted By: oldspark
Date Posted: March 31, 2010 at 6:29 PM

Which terminal are you talking about?

On the heavy side, one is connected to battery +12V, the other is only +12V when the voltage exceeds whatever voltage. (It is normally open - ie, only closed when above whatever voltage.)

I assume the light terminals are GND, and its sense & supply from batt+12V.
If you break either, the relay will open.

Alternative set ups include a relay controlled by the ACC position (off whilst cranking); the alternator-regulator's charge lamp circuit (ie, parallel the batteries or connect the load only whilst charging), or having a low-voltage cutout (MW728) control a relay.

Posted By: coolen
Date Posted: April 01, 2010 at 5:27 AM

so my idea would work then

Posted By: oldspark
Date Posted: April 07, 2010 at 6:35 AM

If it's in accordance with what I said, then yes.

Otherwise....

oldspark wrote:

Which terminal are you talking about?