How do I properly install a battery Isolator 4

[gr8fandini]

Want to add a deep cycle battery to run my acc. when the vehicle is not running. What would be the proper way to install an isolator so that I'm only using the deep cycle when the key is off or in acc. position?

 

[patprimmer]

I would open the packet the isolator came in and read the instructions as a starting point.

Regards
Pat
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[gr8fandini]

Instructions....... Good idea, just trying to figure out if it's worth my while to add a deep cycle or just purchase 2 deep cycles as my starting batteries (vehicle takes two). Would cost me more than double to purchase deep cycles and I still would not have the acc. draw isolated from the starting batts. Have seen a few reviews on some of the isolation switches and many complain about the lack of concise instructions. Thought I would ask a few questions first.

 

[patprimmer]

So your real question is do we know a brand of isolator that has good instructions included.

As I understand it battery isolators are designed to isolate one battery for normal vehicle use and one for ancillary only use for extended use without the engine running and to not drain the starting battery, THEN to recharge each battery at an appropriate rate without the ancillary battery drawing dangerous charge rates from the other battery.

If that is their design purpose, simply wiring them up as normal in the instructions must be all that is required.

Regards
Pat
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[gr8fandini]

I've been looking online for parts or a kit, but I'm not sure a kit that was designed for another use (i.e. Marine) would be a good idea (MARINE=MONEY!!!!) and I know if I bought parts only I could desighn it to operate exactly they way I want. Maybe a link to reference some schematics is where I need to start, any ideas?

 

[gr8fandini]

I guess I ought to give you an idea of the way I want to set it up. I would like to draw power from the aux. battery when the ignition key is off or in the acc. position. Then when I turn the key to the on/ignition position I wish to bring the starting batteries into the cicuit to start the vehicle. While the vehicle is running I want to have the aux. battery in the cicuit with everything else to charge it. I know these types of setups exist in marine applications, but as I stated, any setup that involves marine parts is extremely expensive and most of them are set up to switch to shore power when available, something that I don't need.

 

[patprimmer]

4 wheel drive accessory outlets have them specifically for running camping gear off one battery and the vehicle off another with regulated charge rate to both batteries when running. I think from vague memories that the two cannot be just in parallel on charging as one battery can supply to much current to the other if charge levels are to different and therefore it needs a dual regulator.

Two alternatives are to run dual alternators so that each one independantly charges its own battery and keep both systems totally independant.

I am sure something could be worked out with a few relays and diodes and maybe a voltage controlled switch or maybe even a timer.

Regards
Pat
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[evelrod]

The isolator on my motor home is pretty simple. It just links the house batts to the vehicle charging system when the engine is running. All other times the vehicle and house batts are separate. On my setup I added a Ford starter solenoid and a push button switch on the dash so that if I ever needed to use the house batts to start the engine all I need do is push the switch and both systems are linked.
It came in handy once when the house batts were to low to start the on board generator. Pushed the button and, voila, power!

Rod

 

[gr8fandini]

That's a clever idea evelrod, and your ideas have spurred some thought as well patprimmer. Gotta go to a meeting will check back in with some thoughts later.

 

[LionelHutz]

There are fairly cheap isolators available. Hook the alternator output to one post and a battery to each of the other 2 posts. The alternator can then charge both batteries without one battery discharging the other one. I'm thinking easily less than $100. Not rocket science.

You could also get some continous duty solenoids so you can connect the batteries together when you want them in parallel.

 

[gr8fandini]

Thanks Lionelhutz. I'm getting some great suggestions here and that's getting the creative juices stirring. I want to keep this simple, but with the suggestions I'm getting here that might not happen. Currently I'm leaning towards a pair AGM batteries as the mains and I want to back them up with a deep cycle or two.

 

[dicer]

What you need is some or one latching relay/s. Pretty simple to connect.
The problem is you would not want to remove both batterys from the circuit at the same instant, you would first have both in parallel and then remove one or the other. Or just have the relay to remove the main vehical battery and always have the deep cycle one connected, this maybe the best way to go. Because it makes switching simpler and you get to constantly charge both batterys, when running down the road.

 

[LionelHutz]

There's 2 things being discussed here. The origional request was to have an accessory battery so the main battery was not drained during accessory operation without the engine running. This can be handled by a semiconductor device. I've seen them many times, they're a big chunk of heatsink with 3 terminals that allow both batteries to charge from a common alternator while still keeping them seperate. I believe they are just 2 diodes on the heatsink.

The other one is allowing 2-way power where the auxilaries and main could operate independently or together. This would require some type of high current DC relay, similar to a starter solenoid but rated for continous use.

 

[waross]

If you are driving a vehicle that presently requires two batteries, it may be better to add a third battery (via an isolator) for your accessory loads. The power out wire from the alternator is connected to the input of the regulator and the two output terminals of the isolator are connected to the two battery systems.
Automotive charging is voltage controlled, not current controlled. The alternator outputs the maximum charging voltage and any/either battery that is below that voltage will charge until it is up to the charge voltage.
The isolator diodes prevent either battery from feeding the other system. It is two separate battery systems charged (through the isolator)by a single alternator.
A push button controlled solenoid may be added to temporarily connect both systems together should the need arise. The solenoid should be capable of carrying starting current. It may be intermittent rated. It should be push button controlled and used only in case of need. It will defeat the purpose of the isolator to leave the batteries connected with a switch or solenoid.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[waross]

I don't know about your screen but this sponsored link appears below my post on my screen.

http://www.ASE-Supply.com/Isolators

Unfortunately the link doesn't work.
Try this one.

http://www.ase-supply.com/category_s/153.htm

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[waross]

Here's a picture;

http://www.bcae1.com/battiso.htm

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[waross]

Here is a picture;

http://www.bcae1.com/battiso.htm

Here is your friend

http://www.google.com/

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[LionelHutz]

Here is your friend

http://www.google.com/

like this?

http://www.lmgtfy.com/?q=battery+isolator

The Hellroaring ones look interesting...