Dual battery switch and isolator

[salvageyard saviour]

These are new to me and I think I burnt the isolator. Guest 2111 switch and 2401 isolator.

Using one battery only and connected to 2 position of switch.

While trying to do carburetor work on a 1968, 283ci 210hp OMC. After running long enough to reach operating temp the volts climbed to full field (16+). Alternator and ballast were very hot to touch.

Assumed external regulator is bad. Installed a used one from a 73 OMC but accidentally left the sense wire poorly connected.

Voltage started okay then got very erratic. Shut down right away. Fixed connector. Now no power from isolator. Did the surge fry it?

I moved battery to #1 position on switch, still no power from isolator. Moved wire connected to output of isolator to output of #1 from switch. (Bypassing isolator)Works.

Can I use just the switch? Or should I buy another isolator? What's the benefits of both?

 

[dingbat]

These are new to me and I think I burnt the isolator. Guest 2111 switch and 2401 isolator.

Using one battery only and connected to 2 position of switch.

While trying to do carburetor work on a 1968, 283ci 210hp OMC. After running long enough to reach operating temp the volts climbed to full field (16+). Alternator and ballast were very hot to touch.

Assumed external regulator is bad. Installed a used one from a 73 OMC but accidentally left the sense wire poorly connected.

Voltage started okay then got very erratic. Shut down right away. Fixed connector. Now no power from isolator. Did the surge fry it?

I moved battery to #1 position on switch, still no power from isolator. Moved wire connected to output of isolator to output of #1 from switch. (Bypassing isolator)Works.

Can I use just the switch? Or should I buy another isolator? What's the benefits of both?

If you only have one battery the isolator serves no purpose. Just use the switch.

 

[salvageyard saviour]

I plan to use a second battery later, mostly for electric downrigggers yet to be installed.

Only using 1 battery now while working on engine that hasn't been ran in 20 years.

 

[dingbat]

I plan to use a second battery later, mostly for electric downrigggers yet to be installed.

Only using 1 battery now while working on engine that hasn't been ran in 20 years.

You could replace, but I would looked into a Blue Seas “add a battery” kit.

Not a fan of 1/2/both switches

Add-A-Battery Kit - 120A - Blue Sea Systems

Simplifies switching and automates charging for a complete two battery bank solution.

www.bluesea.com

 

[440roadrunner]

I am not a fan AT ALL of solid state "isolators." These are nothing more than 2 diodes on a heat sink, and diodes can fail. What happens?

Let's say you have an RV, with one of these. The VR sense wire goes to the main battery, the isolator feeds both the main and RV battery, and "everybody" is somewhat happy. The main battery sees MOST OF THE CURRENT so that diode is MOST LIKELY to fail. And they do sometimes

What's next?

The voltage sense is on the main, with the blown isolator diode, slowly going dead. The sense tells the VR HEY!! We need CHARGE!!! And ramps up the VR to FULL OUTPUT!!! But the sense does not see that as the blown diode is blocking current to the main.

So now the RV battery is BUBBLING AND BOILING FURIOUSLY as the alternator is at full tilt to that battery

Know what? There was a boat on Lake Pond Oreille that suffered a bad engine explosion because of one of these. Several I'm aware of (I sold auto parts for about 15 years) cause battery failure/ rupture in RV or pickup installations.

USE A CONTINUOUS DUTY SOLENOID for charging. Personally I see nothing wrong with an A/B/ BOTH switch as long as it's a quality product, is installed away from splash, and NOT SWITCHED HOT.

 

[sam am I]

I am not a fan AT ALL of solid state "isolators." These are nothing more than 2 diodes on a heat sink, and diodes can fail. What happens?

How old are the Isolators and/or are they being wired properly?

I can totally disconnect one and/or two of three batts on my three bank diode battery Iso and the sense voltage that feeds the alt never exceeds the lowest battery voltage plus the Vf of the diode (0.2V/0.3V Schottky Type)

Most if not all more modern(maybe 70's on) diode (or FET) Isolators have a onboard "sense" connection terminal.........Internally, this connection is wired to not only provide compensated sensing feedback for thermal tracking because of varying Vf of the diode's/FETs PN junctions verse temp, it also "OR's" the two voltages..........Therefor, if one or the two diodes opens to one or the other of the two battery's, the remaining battery's connection through the remaining diode/FET will not allow the sense voltage to climb above battery's cell voltage plus the forward voltage drop of the diode (VBatt + Vf = Vsense).

Know what? There was a boat on Lake Pond Oreille that suffered a bad engine explosion because of one of these.

I've practically lived my entire life boating/working/fishing on lake Pend Oreille, not to say this couldn't have happened as I don't know of every instant of every accident, but this I never heard of, a diode isolator caused a "engine to explode"? WTH? When was this? I'm curious if there's a bit more here..........Is there a news report or link you can share? I know the few the Marine Deputies and some of the regular Navy guys I used to work with there, I can perhaps do some digging.....

 

[salvageyard saviour]

It's still going to full output.
Going to wire single battery, no switch, no isolator.
Something wrong with voltage sense, so I'll see if it's somewhere else in the system and not the dual battery stuff.