What is this?
 

Found this while cleaning the garage.

Looks like a big heat sink for charging a battery? someone here will know for sure

I think it's a Solid State Battery Protector.

That's the limit of my helpfulness :)

Possibly a one way charging module for a secondary battery. Allows the second battery to charge but not discharge the primary(starting) battery when a load is applied.

:confused2

Found this after a quick search

https://forums.maxperformanceinc.com...6&d=1640209401

It's an RV charging system splitter. You need to isolate the "car" battery from the "house" battery when charging them by the alternator while driving the RV.

Typically the house battery also gets charged by a charger that runs off 110VAC, either plugged into the campsite power or when running the generator.

Side note, that requires an ATS, or automatic transfer switch. You'd need the same type of switch for your home if you hard-wire a whole-house generator so the guys working on the power lines during an outage don't get electrocuted from backfeed power from your house.

Alum scrap

Hehehe ... that made me laugh.

battery isolater. used to charge 2 batteries and if one goes dead from use without the machine running the other battery stays charged to start the machine. Often used on boats limos and cars running stereo without the car running

Also commonly found in pickups with dual batteries and tow vehicles with batteries in the trailer that are charged by the truck. They were factory options as far back as the late 1960's on GM's and other manufacturers.
Allowed you to run the lights in your camper all night and still be able to start the engine in the morning

I thought it was a McGanzer Flange but dataway would've recognized that.

Guess it's that charging circuit isolator module thingy...


Frank

These are true. Also, dissimilar batteries need to be isolated as well, they will discharge if joined.

Typically, no. The isolator does just what it's called, it isolates the second battery from the rest of the vehicle's original electrical system Here's a typical schematic, there are a number of them online (just search for 'RV battery isolator wiring diagram'.)

https://images.etrailer.com/static/i...259273_800.jpg

Thank you sir ... I was "This Close" to identifying it as a McGanzer Flange :)

Actually my 2011 GMC has one built in, cables hanging by a spare battery tray just waiting for the battery I never installed.

While it looks sophisticated, it is still a couple of diodes with a big heat sink. I had problems with them and prefer a simple large solenoid switching the RV battery in line when when the ignition switch is on (and isolating the two when ignition is off). Maybe it was just luck of the draw, but I had two isolators where the diodes didn't switch off and drained the vehicle battery. The local RV repair said they replace them with the old reliable solenoid when the isolators go bad. Might be why this one is in your garage instead of installed.

I think it's missing a McGanzer Flange, would probably work great if it had one.

I also prefered to install the solenoid system. I found it to be more reliable, smaller, and easier on the charging system. The isolator will lower the voltage from the alternator connection to the two battery connections by 1/2 to 1 volt. If anyone is thinking about using the solenoid system, be sure to use a solenoid that is made for continous duty. Start solenoids are limited duty and will fry if used for this application.

the ATS is unrelated to the battery isolator. That's why I wrote "side note" as I was referring to the 110 volt AC circuitry.