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Hellroaring Technologies, inc.

Polson, Montana  -  USA

Our 4 way switch Page 

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4 Way Switch. Starter and Loads Common.

If  you like the ability to switch from one battery to the other battery,  then consider Figure 3 below.    Connect a simple micro-switch to the BIC-75300 so you can manually combine batteries before switching.    This will reduce arcing and save wear on the switch contacts.    As above, the remote manual switch and remote LED indicator connections are not shown.

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Figure 3


  • Optimized configuration for a single "two-bank switch".
  • Simple.    Minimal wiring needs.  
  • External solenoids NOT required.   Can be used with  up to a 110 Amp alternator.
  • Two or more can be used in parallel to increase current handling capacity.
  • Medium Cost.   (Unless you already own the switch.)
  • Simple to understand, installation!  
  • Simple automatic charging operation!    No need to leave the switch in the Both position for charging.   No hassle, worry free.
  • Ability to switch positions while the engine is operating (even to OFF) without damage to the alternator.   The only risk here is in the event of a circuit failure that causes the circuit breakers to open while the engine is running.
  • Simple manual parallel combination via a remote micro-switch.    From a remote console, you can use very small wire running a long distance to switch the batteries in parallel.  
  • The Hellroaring BIC-75300 and BIC-75150 limits inrush currents when switching.   No arcing to wear out the device!
  • Ability to switch from one battery at 50% discharge to the other battery for an additional 50% discharge thereby extending battery life.  
  • No diode voltage drop effect when ON!  

Cons: (these may not all be cons)

  • Alternator protection device recommended.   If the circuit breakers, fuses, or fusible links open while the engine is running, the alternator may be damaged.
  • The dc load buss voltage will drop while starting.   Electronic devices sensitive to this may experience trouble.   Consider moving the starter load to either position 1 or 2 on the switch (see Figure 4.)
  • In this configuration, the BIC-75300 handles up to 110 amps continuos for either battery circuit and up to 170 amps total from the alternator when "ON".   We recommend you limit your alternator size to 110 Amps for this circuit.   When combined manually, it will handle up to 150 amps short term between batteries.    Therefore, when starting while you have one dead battery, the switch must select either the good battery or both but not the dead one unless you have allowed at least 15 minutes for charge to transfer. 

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Copyright 1998-2008 Hellroaring Technologies, inc.
Last modified: 1/5/2008