Solenoid isolator won't disconnect chassis and aux battery, causing depletion.

[Basement Yeti]

And I am certain it's the solenoid isolator, but I can't figure out why. The status light on the solenoid isolator is on indicating the solenoid is connected and both batteries are connected together thus they are trying to equalize with each other. I think.

This is the solenoid isolator I have, model 48525, 85A.
http://www.its-distributing.com/Portals/5/Products/Cole Hersee/ColeHersee 48530 Brochure.pdf


I am using a yellow top Optima battery for my chassis battery, and a blue top Optima battery for my auxiliary battery.

The right side terminal on the isolator is connected to the positive top post stud on my aux battery, and the left side terminal on the isolator is attached to the positive jump post on my chassis battery, with 1 gauge cables.

From the negative top post stud on my aux battery to the negative jump post on my chassis battery I have a 1 gauge cable run.The manual does not say to connect the aux and chassis batteries together directly with a ground cable, but for jump starting purposes this cable is needed. I disconnected this cable for a few minutes and the solenoid isolator did not shut itself off anyway.

The ground wire on the solenoid isolator is connected to a screw drilled into the rib on my van. When I remove this screw the solenoid isolator shuts itself off, thus solving the problem of my chassis battery depleting, but disallowing my aux battery from charging.

Does anyone have a clue as to why the solenoid isolator isn't disconnecting the batteries?

 

[MakersTeleMark]

Try removing the ground connections between the 2 batteries.

 

[pods8]

Sounds like you have an always "hot" line connected to the positive terminal on the switch portion of the solenoid which is why when you undo the neutral/ground line it opens up (the circuit has finally been broken). You either need that line to only be ignition positive or put a switch in the line so you break the circuit going through the top posts. Otherwise yeah it'll stay connected the whole time.

 

[Basement Yeti]

I disconnected the black 1 gauge ground cable going from the aux to chassis battery.

Pods, I am not sure what you mean. The positive cable from the solenoid runs to the top jump post on the chassis battery. You mean instead of running the 1 gauge positive cable from the solenoid to the jump post on my chassis battery to run it to the ignition post on my main electrical control box on my van? If I did that then I could not self jump start myself, I had that problem.


I'll report back with findings.

 

[pods8]

Your solenoid has 4 posts.

The two on each side are the main "switched" path of the solenoid, those connect the two battery positives together. The other two on the top are for turning the solenoid on and off, one gets a positive line and one gets a neutral/ground. The only way the solenoid opens/closes is when the circuit on the top posts is connected/disconnected. You stated above your solenoid is always connected until you disconnected the neutral line coming from the top post. In that case you must have wired an always hot line on the positive top post of the solenoid. The only way to get your solenoid to open/close is to either put a manual switch in that line (in which case you need to remember to turn the solenoid on and off) or run an ignition hot only line to the solenoid so it opens/closes when the ignition is engaged/disengaged.

 

[Basement Yeti]

The ground wire comes out of the bottom of the solenoid isolator, it's prewired just like the status and boost lines, that ground wire is the wire that is connected to the rib of my van providing ground/neutral.

The dimensions diagram in the PDF shows what my solenoid looks like, there are no posts on top, just the two side posts, and the two posts on the front, plus the three wires coming out the bottom.

 

[pods8]

My bad, I didn't follow the link and thought it a normal solenoid. Sounds link the voltage sensing 12.7V disconnect is screwed up.

 

[dwh]

Connecting the grounds is not a problem. They'd both be connected via the frame anyway, so leave the big neg-neg cable in place.

The behavior sounds normal for that unit. It does not isolate the batteries until the voltage of the tied pair drops to 12.7v.

So the question is - ARE they getting down to 12.7v? And IS it disconnecting them when they get to 12.7v? If so, then it's working as designed. If not, then it's stuck on.


(And a quick note on nomenclature: DC has no neutral - that's for AC only, and a vehicle has no ground because it isn't connected to the planet. So to say, "ground/neutral" is all wrong. The proper term is "negative". Yah, I know...picky picky... )

 

[pods8]

Very true I usually say negative/ground since folks often misuse ground rather than negative, no idea why I was typing nuetral earlier though. Been a long day.

 

[Basement Yeti]

Connecting the grounds is not a problem. They'd both be connected via the frame anyway, so leave the big neg-neg cable in place.

The behavior sounds normal for that unit. It does not isolate the batteries until the voltage of the tied pair drops to 12.7v.

So the question is - ARE they getting down to 12.7v? And IS it disconnecting them when they get to 12.7v? If so, then it's working as designed. If not, then it's stuck on.


(And a quick note on nomenclature: DC has no neutral - that's for AC only, and a vehicle has no ground because it isn't connected to the planet. So to say, "ground/neutral" is all wrong. The proper term is "negative". Yah, I know...picky picky... )

I am not sure if the solenoid is stuck on. For the past 3 days I have left the van without starting it. At first the voltage was 13.6, then over the course of 2 days it dropped to what you said, 12.7V. Yesterday when I checked the voltage was 12.7 at 4pm, now today at 11am, nearly 20 hours later the voltage has dropped by .5-.7Vs.

The LED indicator never shut off when the battery was at or below 12.7.

 

[Basement Yeti]

Also, I was thinking. If I got a dual battery MPPT controller to charge both batteries from my solar panel setup I plan on investing in, wouldn't that conflict with the solenoid isolator?

The solar controller would constantly monitor the batteries and turn itself on, thus keeping the batteries at 13.6v. If the solar controller did that then that means the solenoid would never open and the batteries would be constantly connected.

Maybe since this solenoid isolator is probably broke I should go with a simpler isolator like this?
http://atrwatersports.com/images/10840.gif

With this I could still connect the two batteries together to jump start myself, right? And it'd be a better solution since I can control separating the batteries.

Sorry for all the threads and being a dumb ***, I appreciate your help guys.

 

[dwh]

That's not an isolator, that's a switch.

A solenoid isolator would be exactly what you have, but without the little black box to switch the solenoid on and off.

So you take a standard solenoid - like the one that is on your isolator now - and wire it so it ties the batteries when the key is on "run" (not when the key is on accessory). The, when you turn the key on, they are tied and you start the truck. Once the engine is running, they both charge.

What I just described is a normal, regular ol' "split-charge relay" that's been used in boats and trucks and RVs since around the time Alexander the Great lived in Jericho. Simple and bulletproof. That is what I personally use in my truck.


The unit you have is a split-charge relay - with a little black box added on to sense voltage and energize the solenoid. Powerstream is the same thing but with 13.6v/12.6v instead of 13.2v/12.7v like yours has:

http://www.powerstream.com/battery-isolator.htm



As for the dual solar - MPPT is expensive. Dual MPPT is hideously expensive. And neither one is worth the money for a small under 200w solar setup.

But yea, if your existing solenoid (which BTW I don't like and would never use) ties the batteries whenever the engine battery gets to 13.2v...then you wouldn't really need a dual controller, just run a single to the engine battery and let the isolator tie in the aux once the engine battery comes up enough.

And no, there wouldn't be any conflict even if you used a dual. It would basically be two charge controllers charging two separate batteries - and then at 13.2v it would be two chargers charging a single battery bank.

You can hook up many different chargers to a single battery or battery bank - the chargers won't butt heads.

 

[Basement Yeti]

So since my isolator isn't working, obviously, what do you recommend I do? I have the receipt and it's under warranty so it's getting returned.

Do you think I should replace it with a switch? I like the idea of a switch. It's simple. Less to break.

 

[dwh]

Split-charge relay.

Get one of these:

http://www.amazon.com/SOLENOID-GOLF..._9?s=automotive&ie=UTF8&qid=1311306915&sr=1-9


Which is exactly what you have, but without the little black box controller on it.

Wire it up so it's on when the key is on and forget about it.

That's what I have.

 

[Basement Yeti]

Can I self jump start myself with that?