Battery Isolator Malfunction

Question

I have the Intellitec Big Boy solenoid and a BIRD Diesel controller which is the battery isolator.

Yesterday on shore power the house battery was being charged and the chassis battery needed to be charged (12.5V) but the solenoid was not connecting the two battery posts.

The solenoid was humming and the coil voltage was about 4V. My understanding is that this is normal after the initial 12V pulse to engage this latching solenoid.

With further testing in mind for this morning, it’s now working and charging the chassis battery. I now suspect that the solenoid operation is intermittent and it needs to be replaced.

Anyone else seen this or have any suggestions?

bdpreece · Answer

Maybe my thread on when my starting batteries would not charge would be of interest to you.  See Post #39 for a picture of what my relay looked like.  Dead starting batteries

onaquest · Answer

CA Traveler wrote:I have the Intellitec Big Boy solenoid and a BIRD Diesel controller which is the battery isolator.Yesterday on shore power the house battery was being charged and the chassis battery needed to be charged (12.5V) but the solenoid was not connecting the two battery posts. The solenoid was humming and the coil voltage was about 4V. My understanding is that this is normal after the initial 12V pulse to engage this latching solenoid.With further testing in mind for this morning, it’s now working and charging the chassis battery. I now suspect that the solenoid operation is intermittent and it needs to be replaced. Anyone else seen this or have any suggestions?First off, the Big Boy Isolator solenoid is NOT a latching solenoid,  It requires sufficient voltage across the coil to remain closed.I suspect you are right in thinking that the solenoid is failing.  Probably due to the constant coil heat, but that 4V sounds a little low from my experience and could be an indication that the Bird circuitry is beginning to fail.  Typically, the bird output only drops to about 8-9 volts.I would replace the solenoid before it ruins the Bird.

ca_traveler · Answer

Oops, I was thinking of the Big Boy battery disconnect which is a latching solenoid.

Appears to working OK this morning. Coil is 3.1V and 1.4A and case temperature is 105F, about 75F ambient and humming away nicely.

Think I'll call Intellitec before I buy another unit.

ca_traveler · Answer

Brian, Your link is Dead starting batteries

bdpreece · Answer

Oops;  Lets try this Dead Starting BatteriesThat one should work and shows the inside of my bad solenoid.

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Battery Isolator Malfunction

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