Dual Battery Isolator Help

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by CarpenterGuy, Apr 28, 2013.

  1. CarpenterGuy

    CarpenterGuy Epic Member 5+ Years 500 Posts

    Hey guys, I haven't been on here in a looong time due to college! But I'm in need of help, so I'm turning to the best source of truck info I know of. I need to put a dual battery isolator in my truck. I work in construction on the side and I charge tool batteries off the truck, run the radio, and at night, run the lights. I'm always horrified that my battery is going to die and i'll be stuck (i've had some pretty close calls). I'm looking at a battery isolator, but I don't know what to get. I've seen different isolators at different amp ratings and I have no idea what I should be getting. If anyone could guide me in a direction, or even show me what product to buy, it would be greatly appreciated!

    Also, I have another problem that I have. My rear brake lights (excluding the cab mount) aren't working. I've replaced the bulbs, checked fuses, and checked all connections that I could get to. What other things could it be? Someone was telling me something about a signal box in the steering wheel, but I didn't understand what he was saying.

    Thanks for the help!
  2. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    By 'dual battery isolator' I presume you mean you want two-way isolation ... so that you could, say drain one battery and not impact the other ... or even jump one battery off the other. If that's the case, look into a dual rectifier by Perfect Switch. It's MOSFET-based, so it won't have the voltage drop associated with diode-based isolators ... and it will be a hell of a lot more reliable than solenoid-based isolators. It's potted, as well, so it'll withstand the rigors of being in ugly environments (mud, snow, salt, sand, you name it...).

    Here's a link: http://www.perfectswitch.com/isolators/dual-rectifier-isolator/

    I run a 300 amp dual rectifier, myself, by the way. I've had it for more than a year and never had one issue. Be warned, though ... these are not cheap ... and you absolutely do get what you pay for. These guys are suppliers for NASA, General Dynamics, L3 Communications, US Navy, US Army, Lockheed Martin, Raytheon, and the FBI...
  3. CarpenterGuy

    CarpenterGuy Epic Member 5+ Years 500 Posts

    Do i need a 300 amp? Also, would i have to change out the stock alternator for a beefier one?

    $700 is quite a bit to spend. Are there any less expensive that you would recommend? I understand that they wouldn't be as good.

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    Also, wouldn't a single rectifier work? I don't mind the aux battery being used to start the truck, i just don't want the main battery to run the aux.
  4. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    You said 'dual isolatation' so I linked you something meeting that criterion that is as close to bullet-proof and ideal (in terms of functionality) as it gets. Whether you require a single or dual rectifier is totally up to you, as it's an application-dependent choice. Likewise, how many amps you require is application dependent and totally up to you.

    There are a plethora of ways to do battery isolation. You'll need to do some homework to determine the approach that best suits the combination of your application's needs, your reliability requirements, and your budget.
  5. CarpenterGuy

    CarpenterGuy Epic Member 5+ Years 500 Posts

    alright, thanks for the help.
  6. Z71_guy

    Z71_guy Epic Member 5+ Years 1000 Posts

    for the brake lights could be your brake light switch by the brake ped
  7. j cat

    j cat Epic Member 5+ Years 1000 Posts

    the rear lamps go thru a block mounted on the rear /under bed area. this some have had corroded or damaged connectors/board interface. since the cab light lights and not the tail lamps this is the most common cause. ////your sure the fuses are good ?

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    battery isolator with diodes is not good because of the voltage drop. the other method using an switching diode rated to handle battery power is nice but very expensive.

    boaters like myself have 2 batteries one is for starting , the other to operate the fish finding and depth , pump , radio etc operating electrical equipment. we use these type of manual switches . reliable and not expensive . you will need to buy heavy gauge copper wire and properly secure the wire with soldering and using the proper heat shrink to protect the wire junctions .

    after a day of fishing , what you don't want is a dead battery ..


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