Q.   WHAT IS A "BBS" (BEST BATTERY SELECTOR)?
A.    A BEST BATTERY SELECTOR IS A DEVICE THAT IS INCREASINGLY USED IN ENGINE STARTING ENVIRONMENTS THAT DEMAND EXTREMELY HIGH RELIABILITY. MANY
       SPECIFICATIONS NOW CALL FOR TWO SETS OF BATTERIES TO BE COUPLED TO A SINGLE ENGINE. IF ONE SET IS WEAK OR DEAD, THE OTHER SET CAN STILL START THE
       ENGINE. A BBS COUPLES THESE TWO SETS OF BATTERIES TO A SINGLE ENGINE, AUTOMATICALLY USING WHATEVER CURRENT IS AVAILABLE FROM BOTH SETS OF   
       BATTERIES TO START THE ENGINE, BUT AT THE SAME TIME, ISOLATING THE BATTERIES SO THAT ONE BAD SET DOES NOT BRING THE OTHER SET DOWN.
Q.    HOW ARE "EQUALIZE", "BOOST" AND "FAST CHARGING" DIFFERENT?
A.    EACH OF THESE TERMS DESCRIBES THE SAME FUNCTION OF THE CHARGER WHERE THE CHARGER TEMPORARILY ELEVATES THE BATTERY'S VOLTAGE ABOVE THE FLOAT  LEVEL.

                          COMMONLY UNDERSTOOD MEANING OF THE TERM:
​       EQUALIZE          PERIODIC "TOPPING UP" OF BATTERY CAPACITY AND CORRECT CELL CAPACITY DIFFERENCES.
       BOOST                CAN REFER TO "EQUALIZE", "FAST CHARGE" AND SOMETIMES BOTH.
       FAST CHARGE   FASTER RECHARGE OF A DISCHARGED BATTERY.

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BATTERIES / CHARGERS
Q.    I FIND THE MANY DIFFERENT TERMS USED WITH LEAD-ACID BATTERIES CONFUSING. CAN YOU CLARIFY?
A.    YES. PLEASE REFER TO BATTERY GLOSSARY.

Q.  HOW DO I IDENTIFY A MARATHON ELECTRIC GENERATOR FROM THE GENERATOR MODEL NUMBER?
A.  CLICK ON GENERATOR MODEL CODES FOR MATRIX OF GENERATOR MODEL CODES TO DETERNINE THE GENERATOR TYPE, FRAME SIZE, NUMBER OF BEARING, VOLTAGE RANGE AND 
      SPECIAL ENGINE ADAPTIONS.
Q.  WHAT ARE THE ADVANTAGES OF ADDING A PMG TO A SYNCHROUNOUS GENERATOR?
A.  CLICK ON PMG FOR AN ARTICLE DISCUSSING THE ADVANTAGES OF PMG EXCITATION SUPPORT SYSTEM.


Q.    IF I USE A BBS, CAN I USE ONE BATTERY CHARGER TO CHARGE BOTH SETS OF BATTERIES?
A.    NO. EACH SET OF BATTERIES REQUIRES A CHARGER SO THAT IT CAN BE INDEPENDENT AND ISOLATED FROM THE OTHER SET OF BATTERIES.
Q.  WHAT IS A SYNCHRONOUS GENERATOR?
A.  A SYNCHRONOUS AC GENERATOR (ALTERNATOR) IS AN ALTERNATING CURRENT GENERATOR WHOSE ROTATING SPEED IS DIRECTLY PROPORTIONAL TO THE FREQUENCY OF THE AC
      VOLTAGE WAVE IT PRODUCES. ALL MARATHON MAGNAPOWER®, MAGNAMAXDVR®, MAGNAPLUS®, PANCAKE®, and LIMA®MAC GENERATORS ARE SYNCHRONOUS GENERATORS.
GENERATORS
Q.  WHAT IS A GENERATOR'S TRANSIENT REACTANCE (X'd)?
A.  THIS VALUE DETERMINES THE CURRENT FLOWING DURIG THE PERIOD WHEN THE SUBTRANISNET REACTANCE IS THE CONTROLLING VALUE.
Q.  WHAT IS A GENERATOR'S SUB-TRANSIENT REACTANCE (X"d)?
A.  THE APPARENT REACTANCE OF THE STATOR(MAIN ARMATURE) WINDING AT THE INSTANT A SHORT CIRCUIT (FAULT) OCCURS. THIS REACTANCE IS USED FOR THE CALCULATION OF
      THE INITIAL MAXIMUM SYMMETRICAL AND ASSYMETRICAL FAULT CURRENT.