Intellitec Bigboy relay

[caymann]

I gave up on diode based battery isolators and bought an intellitec bigboy battery isolator relay, mainly because it can handle 200A (although the alternator will never pump that high).

All i want to do is, have this relay connect the engine and house batteries when the alternator is working and isolate the batteries when the alternator is not powered.

The big boy relay takes a reversing ciruit to energize (CLOSE) and deenrgize (OPEN)

What battery isolator controller do i need?

[texnet]

I don't have the answer to your question, but curious why you "gave up" on the diode based battery isolators? I had one burn out and replaced it with a 200A unit and have had no problems since I replaced it.

[caymann]

Quote:

Originally Posted by texnet I don't have the answer to your question, but curious why you "gave up" on the diode based battery isolators? I had one burn out and replaced it with a 200A unit and have had no problems since I replaced it.

I went thru 2 of these diode based isolators and also lost an alternator due to high heat inside. After speaking to alternator rebuild shop, i decided against getting another 200A diode based isolator.

If you dry camp and run down your house battery, having a diode based isolator (with 0.6V or so voltage drop) means your alternator is working harder to overcome that voltage drop. In the situation when battery is low, this creates more work for alternator and it runs hotter for long time thereby killing the rotor (magnet based) some day. Use generator instead.

I have measured upto 175A of current from alternator in a situation and temperatures inside close to 270F measured using an IR thermometer

If you always use hookups, then no worries.

I can't predict my usage plus if i move to an electric refrigerator someday (when the norcold 1200 dies), this will be a major factor.

[KIX]

You could simply have a manual switch but then you have to remember to use it.

I think Intellitec makes the B.I.R.D. system which would make it automatic

[Mike Canter]

I agree with KIX. This is what normally controls a Big Boy relay in a B.I.R.D. System http://intellitec.com/PDF/5300839.000.pdf. I have this setup on my MH and it works great.

[YC1]

If possible return that relay and buy one that is energized when voltage is applied. You then ground one side of the control of the solenoid and have voltage with the ignition switch in the on position control the action of the solenoid.

If you give me the part number of the solenoid you have I will see if there is a way to do it without a reverser circuit.

I'm glad you mentioned running the generator to charge the batteries because run down batteries can put a tremendous strain on an alternator.

[nodine]

Quote:

Originally Posted by caymann I went thru 2 of these diode based isolators and also lost an alternator due to high heat inside. After speaking to alternator rebuild shop, i decided against getting another 200A diode based isolator. If you dry camp and run down your house battery, having a diode based isolator (with 0.6V or so voltage drop) means your alternator is working harder to overcome that voltage drop. In the situation when battery is low, this creates more work for alternator and it runs hotter for long time thereby killing the rotor (magnet based) some day. Use generator instead. I have measured upto 175A of current from alternator in a situation and temperatures inside close to 270F measured using an IR thermometer If you always use hookups, then no worries. I can't predict my usage plus if i move to an electric refrigerator someday (when the norcold 1200 dies), this will be a major factor.

Do you have the large relay that connects the house batteries to the chassis batteries as my coach does? This is done by a momentary switch labeled Batt Boost. If you do, then get a relay with normally open contacts and connect it across the switch. Connect the coil of the relay to any circuit that is Hot only when the ignition is on. Add a switch in line with the Key On hot wire so that you can disable the circuit when you want. By using the relay and the Key On circuit you will not have to remember to turn the solenoid off when you park. The switch in-line with the coil circuit will let you disable the circuit until you get moving down the road and the alternator has already replenished the chassis batteries with the power used to start the engine.


Bob

[moisheh]

Nodine: Your suggestion is right on but first one would have to make sure that the solenoid is rated for continuous duty. Probably not. There is also another solenoid in his circuitry that is a lock out to prevent the gennie and the alternator from charging at the same time. I dont know if that would affect anything.